Research ArticleForced Air Precooling Enhanced Storage Quality by Activating theAntioxidant System of Mango Fruits
Jian Li 1 Yingli Fu1 Jiaqi Yan23 Huanlu Song 13 and Weibo Jiang2
1Beijing Engineering and Technology Research Center of Food Additives Beijing Technology and Business UniversityNo 11 Fucheng Road Beijing 100048 China2College of Food Science and Nutritional Engineering China Agricultural University Beijing 100083 China3Beijing Advanced Innovation Center for Food Nutrition and Human Health Beijing Technology and Business UniversityBeijing 100048 China
Correspondence should be addressed to Huanlu Song songhlthbtbueducn
Received 23 November 2018 Accepted 11 February 2019 Published 4 March 2019
Academic Editor Antoni Szumny
Copyright copy 2019 Jian Li et al is is an open access article distributed under the Creative Commons Attribution License whichpermits unrestricted use distribution and reproduction in any medium provided the original work is properly cited
Eects of forced air precooling on storage quality and physiological metabolism of mangoes were evaluated in this study Mangofruits were forced air precooled for 30min at 0degC and then stored at 13degC Control fruits were stored at 13degC directly Resultsshowed that forced air precooling treatment maintained fruit rmness inhibited fruit peel coloration retarded hydrolysis ofpolysaccharide to soluble sugar and decreased fruit decay during storage Biochemical studies revealed that precooling treatmentcould eliminate reactive oxygen species (ROS) eects by enhancing related antioxidant enzyme activities such as superoxidedismutase (SOD) catalase (CAT) peroxidase (POD) glutathione reductase (GR) and polyphenoloxidase (PPO) ey allcontributed to the delay of mango fruit ripening and senescence in storage ese results indicate that forced air precoolingtreatment could maintain mango fruit quality by enhancing antioxidant activity and delaying fruit ripening
1 Introduction
Mango is a typical climacteric fruit that is characterized byincreased ethylene production and a rise in respiration duringfruit ripening [1] To reduce postharvest losses mango fruitsare always harvested at the physiologically mature green stageand allowed to ripen after harvest en mango fruits notonly have the best quality for consumption but also aresusceptible to pathogen invasion and begin to senescePostharvest respiration and ripening can constantly de-compose fruitrsquos nutritional compounds resulting in highbiochemical metabolism fruit softening and quality de-terioration and it is closely related to storage temperature[1ndash3] Meanwhile the temperature of mango fruits increasedrapidly after harvest due to both eld heat and respirationheat erefore it is important to cool down mango fruitsimmediately after harvest to delay fruit ripening after harvest
Postharvest precooling is a common process to decreasethe fruit temperature rapidly to the expected core
temperature It not only slows down fruit respiration waterloss and metabolism but also inhibits nutrition loss andpathogen development during subsequent storage [4]Precooling has made a great signicance such as removingeld heat maintaining postharvest quality and prolongingshelf-life in cold-chain transportation for many fruits andvegetables [5 6] Now precooling is regarded as an in-dispensable rst step by many developed countries likeEurope and Japan Among various industrial postharvestprecooling techniques forced air precooling is widely ac-cepted as an eective method to maintain postharvestquality and prolong shelf-life for many fruits like apple andplum [7ndash9] Forced air cooling is much faster than otherconventional cooling methods because the cool air comes indirect contact with the surfaces of the horticultural product[10]
During the late ripening stages fruit senescence wasaccompanied by membrane deterioration programmed celldeath and some other associated biochemical changes [11]
HindawiJournal of Food QualityVolume 2019 Article ID 1606058 12 pageshttpsdoiorg10115520191606058
Excessive production of reactive oxygen species (ROS) suchas O2minus and H2O2 can cause progressive oxidative damageand ultimately cell death accelerating fruit senescence [12]Fruits also produce a natural defense system scavengingROS enhancing membrane stability and protecting fruitsfrom senescence deterioration e antioxidant enzymesystem includes superoxide dismutase (SOD) peroxidase(POD) catalase (CAT) ascorbate peroxidase (APX) andglutathione reductase (GR) Mango fruits also include fla-vonoids which could eliminate O2minus and inhibit senescence ofplants [13]
So far there have been fewer reports on the changes inquality and physiological metabolism ofmango fruits treatedwith forced air precooling In this study the effect of forcedair precooling on postharvest qualities of mango fruitsduring the storage period was investigated e changes ofreactive oxygen species and eliminate system were alsodiscussed
2 Materials and Methods
Tainongmango fruits (Mangifera indica L cv Tainong) wereharvested from a nearby orchard and transported to thelaboratory immediately e maturity of the fruit wasindicted by mature green Fruits that were uniform in sizecolor shape and free of mechanical damage and pathogeninfection were selected for experiments Seventy-two fruitswere placed in a 45 cmtimes 30 cmtimes 30 cm plastic box with 20whole area Each box was placed in a tube which containedan exhaust fan Fruits were forced air precooled with 1ms0degC air for 30min until the central temperature reached 13degCand then stored at 13degC and 85sim95 relative humidity(RH) e control fruits were directly stored at 13degC and85sim95 RH e experiment contained two hundred andseventy fruits Fruit quality was evaluated and fruit flesh andpeel were sampled on the 0th 5th 10th 15th and 20th day ofstorage
211 Weight Loss Weight loss was determined by weighingfruit at harvest (initial weight) and every evaluation time andexpressed as percentage loss of the initial weight
212 Firmness Firmness was measured by using a Boschpenetrometer (Model FT 327) at two opposite points on theequatorial region of mango fruits
213 Color e yellow index of fruit peel was visuallyevaluated and scored on a 0 to 4 scale from green to yellowe yellow index was calculated using the following formula
yellow index() 1 times n1 + 2 times n2 + 3 times n3 + 4 times n4
4 times n
times 100
(1)
where n1 to n4 represent the number of fruits in differentscores 1 to 4 respectively and n represents the total numberof fruit
Fruit peel color was measured by using a chromameter(ADCI-60C China) at two opposite points on the equatorialregion of mango fruits and recorded ldquoLlowastrdquo ldquoalowastrdquo and ldquoblowastrdquovalue
214 Pigment Contents For determination of chlorophyll aand chlorophyll b contents 4ml of 90 acetone was addedinto 10 g of mango flesh (05 g peel) and then centrifuged at10000times g for 20min at 4degC Absorbance of the supernatantwas measured at 663 nm and 645 nm
For all external quality evaluation there were threereplicates in each treatment with one replicate containingten fruits
22 Internal Quality Evaluation
221 Total Soluble Solid Content Total soluble solids (TSSs)content was expressed as using a digital refractometer(Atago PAL-1 Japan)
222 Titratable Acidity Content Titratable acidity (TA)content was titrated by NaOH
223 Soluble Sugar Content For soluble sugar contentdetermination 3 g of fruit flesh was mixed with 60ml ofdistilled water e mixture was heated in a boiling waterbath for 20min and then centrifuged at 10000times g for15min Finally the abstained supernatant was used forsoluble sugar analysis Soluble solid content (SSC) wasmeasured by using an Atago digital refractometer (PAL-1Japan)
224 Starch Content According to Elloumi et al [14] thephenol-sulfuric acid method was used to determine thestarch content 10 g fruit flesh was added into 50ml ofdistilled water and placed in a boiling water bath for 20mine residue was shifted to the graduate test tube added withdistilled water to 10ml and boiled for another 15minen20ml of 96M perchloric acid was added to the graduatedtest tube to extract for 6 h After centrifugation at 10000times gfor 15min the supernatant was collected for starch contentanalysis Starch content was measured by using a spectro-photometer (PerkinElmer Lambda 35 UK)
225 Flavonoid Content 10 g fruit flesh was added in 4mlof 1 HCl-methyl alcohol extracted for 2 h and centrifugedat 10000times g at 4degC for 20min e absorbance of the
2 Journal of Food Quality
supernatant was measured at 325 nm e content of theflavonoids was expressed as OD325g at 325 nm by using aspectrophotometer (PerkinElmer Lambda 35 UK)
For all the internal quality evaluations three replicateswere performed for each treatment and ten fruits were usedfor each replicate
226 Decay Evaluation e decay rate of fruit was visuallyevaluated Fruits with visible disease development wereconsidered decayed and the percentage of decay fruits wasused for expressing decay rate
decay rate total number of decayed fruits
total number of fruitstimes 100 (2)
e decay index of fruit was visually evaluated andscored on from 0 to 4 ere were three replicates in eachtreatment and each replicate contained thirty fruits
23 Reactive Oxygen Species and Related Enzymes
231 O2minus Production Rate According to Liu et al [15] fruitflesh (20 g) was added with 4ml of 100mM phosphatebuffer (pH 78 containing 2 PVPP and precooled at 4degC)and grinded on ice After centrifugation at 10000times g at 4degCfor 20min the supernatant was collected for the mea-surement of O2minus production rate e KNO2 solution wasused to make the standard curve e O2minus production ratewas expressed as nmolmiddotgminus1middotFWmiddotminminus1
232 Malondialdehyde Content According to Hodges et al[16] 10 g fruit flesh was added with 10 (wv) TCA solutionthat was precooled at 4degC After grinding and centrifugationat 10000times g at 4degC for 20min the supernatant was used forMDA measurement by using a spectrophotometer (Perki-nElmer Lambda 35 UK) e MDA content was calculatedusing the following formula
CMDAμmolL
1113888 1113889 645 times OD532 minusOD600( 1113857minus 056 times OD450
(3)
233 Glutathione Content According to Brehe and Burch[17] fruit flesh (10 g) was homogenized on ice with 3ml of5 (wv) TCA solution that contained 5mMEDTA-Na2 andwas precooled at 4degC After centrifugation at 10000times g at4degC for 20min the supernatant was collected for GSHmeasurement GSH content was expressed as nmolmiddotgminus1middotFW
234 Superoxide Catalase Ascorbic Peroxidase and Glu-tathione Reductase Activities Superoxide catalase ascorbicperoxidase and glutathione reductase activities wereexpressed as 001 changes in absorbance at correspondingnm per minute per g flesh tissue by using a spectropho-tometer (PerkinElmer Lambda 35 UK)
Superoxide (SOD) activity was determined according toProchazkova et al [18] and Larrigaudiere et al [19] e
amount of enzyme that inhibited 50 of NBTphotochemicalreduction was defined as a SOD activity unit
Catalase (CAT) activity was determined according toNaima et al [20] and expressed as 001 change in absorbanceat 240 nm per minute per g flesh tissue
Ascorbic peroxidase (APX) activity was determinedaccording to Nakano and Asada [21] and expressed as 001changes in absorbance at 290 nm per minute per g fleshtissue
Glutathione reductase (GR) activity was determinedaccording to Foyer and Halliwell [22] and expressed as 001changes in absorbance at 340 nm per minute per g of fleshtissue
235 Peroxidase and Polyphenoloxidase ActivityPeroxidase (POD) activity was determined according to Zhuet al [23] 500 μL of 05 (vv) guaiacol and 15mL of 50mMacetate buffer (pH 55) were added into 500 μL enzymeextraction e reaction started when 500 μL of0059MH2O2 was added e enzyme activity unit wasdetermined by monitoring the increase of absorbance at470 nm per min e enzyme activity was expressed asUmiddotgminus1middotFWminus1 Polyphenoloxidase (PPO) activity was de-termined according to Zhu and Ma [24] One PPO activityunit was defined as 1 change in absorbance at 420 nm perminute per g of flesh tissue by using a spectrophotometer(PerkinElmer Lambda 35 UK)
24 Statistical Analysis SPSS 110 for Windows (SPSS IncChicago IL) was used for data collection and analysis with aone-way analysis of variance (ANOVA) Duncanrsquos multiplecomparison was used to separate means at the 5 level
3 Results
31 Effects of Forced Air Precooling on External Quality ofMango Fruits during Storage
311 Firmness Mango fruits firmness decreased dramati-cally after harvest while precooling treatment retarded thedecrease e precooled fruit had higher firmness than thecontrol group during the whole period On the 10th day and15th day precooled fruits had 333 and 624 higherfirmness than control fruits respectively (Figure 1(a))
312 Weight Loss As shown in Figure 1(b) weight loss ofmango fruits increased steadily and precooling treatmentincreased fruit weight loss slightly On the 20th day ofstorage precooled fruits had 22 higher weight loss thancontrol fruits
313 Color As shown in Figure 2(a) the yellow index inmango fruits was increased steadily during storage whileprecooling treatment inhibited the color change On the 10thday and 15th day the precooled fruits had 233 and 145 alower yellow index than control fruits respectively e
Journal of Food Quality 3
0
1
2
3
4
0 5 10 15 20
Firm
ness
(N)
Days of storage
ControlPrecooling
(a)
0
2
4
6
8
5 10 15 20
Wei
ght l
oss (
)
Days of storage
ControlPrecooling
(b)
Figure 1 Eects of forced air precooling treatment on rmness (a) and weight loss (b)
Days of storage
0
20
40
60
80
100
10 15 20
Yello
w in
cide
nce (
)
ControlTreatment
(a)
40
50
60
70
80
0 5 10 15 20
Llowast
ControlPrecooling
Days of storage
(b)
ndash30
ndash20
ndash10
0
10
20
0 5 10 15 20
alowast
Days of storage
ControlPrecooling
(c)
30
40
50
60
70
0 5 10 15 20
blowast
Days of storage
ControlPrecooling
(d)
FIGURE 2 Eects of forced air precooling treatment on the (a) yellow index (b) Llowast value (c) alowast value and (d) blowast value
4 Journal of Food Quality
difference between precooled and control fruit was notsignificant at the end of storage
Llowast value from low to high indicates that the lightnessincreases Llowast value of mango fruits peel increased with theprolonging of the storage time Llowast value in precooled fruitswas lower than control fruits during the entire storageperiod On the 10th day the Llowast value of precooled fruits was115 lower than that of control fruits (Figure 2(b)) alowast valuefrom negative to positive represents that the color changesfrom green to red and blowast was from blue to yellow With theextension of storage alowast and blowast values of mango fruits peelwere all increased steadily which showed that the peel colorwas changing from green to yellow Precooling treatmentretarded the increase of alowast and blowast during the beginning ofthe storage On the 10th day precooled fruits had 478lower alowast and 149 lower blowast than that of control fruitsrespectively (Plt 005) e differences between precooledand control fruits were not significant at the end of storage(Figures 2(c) and 2(d))
314 Pigment Content Figure 3 showed pigment changes inmango fruit flesh and peel With the ripening of mangofruits chlorophyll a in mango fruits peel decreased dra-matically and the decrease of control fruits was higher thanprecooled fruits On the 20th day of storage precooled fruitspeel had 84 higher chlorophyll a than control fruits(Figure 3(a)) Chlorophyll a in mango fruits flesh was alsodecreased dramatically On the 10th day precooled fruitsfresh had a significantly higher level of chlorophyll a thanthat of control fruits At other times there was no significantdifference (Figure 3(b))
e change tendency of chlorophyll b in mango fruitspeel was similar to chlorophyll a and precooling treatmentalso retarded chlorophyll b reduction On the 15th and 20thday of storage precooled fruits peel had 188 and 200higher chlorophyll b than that of control fruits re-spectively (Figure 3(c)) However there was no significantdifference in chlorophyll b between precooled fruitsflesh and control fruits flesh during the storage period(Figure 3(d))
32 Effects of Forced Air Precooling on Internal Quality ofMango Fruits during Storage
321 Total Soluble Solids As shown in Figure 4(a) TSS ofcontrol fruits increased during the first 15 days and thendecreased Precooling treatment retarded the increase ofTSS and there was no decrease until the end of storageerefore on the 20th day of storage the TSS in precooledfruits was 116 higher than the control
322 Titratable Acidity Figure 4(b) showed the changes ofTA content in mango fruits during storage TA in mangofruits changed slightly during first 10 days after which TAdecreased rapidly Precooled fruits exhibited less decreasecompared to the control On the 15th day precooled fruitshad 395 higher TA content than control fruits
323 Soluble Sugar Content Soluble sugar content ofmango fruits in both precooled fruits and control fruitsincreased steadily with the increase of storage time At thebeginning of storage soluble sugar content in precooledfruits was slightly lower than that of control fruits At the endof the storage however soluble sugar content in precooledfruits was slightly higher than that of controls fruit But therewas no significant difference between the two groups(Figure 4(c))
324 Starch Content Figure 4(d) showed that starchcontent decreased continuously during the whole storageperiod On the 20th day starch content was only 25 of theinitial value Precooling treatment delayed the decrease ofstarch content during the beginning of the storage periodOn the 5th 10th and 15th precooled fruits had 273 223and 377 higher starch content than the control grouprespectively
325 Flavonoid Content As shown in Figure 5 flavonoidscontent was decreased in both precooled and control fruitsand then increased slightly at the first 5 days Flavonoid inprecooled fruits increased more rapidly than that in thecontrol On the 10th 15th and 20th day precooled fruits had103 112 and 61 higher flavonoids content thancontrol respectively
33 Effects of Forced Air Precooling Treatment on Decay In-cidence and Decay Severity of Mango Fruits during StorageDecay incidence and decay severity of mango fruits that werestored at 13degC and 85sim95 RH was shown in Figures 6(a)and 6(b) Precooling treatment decreased fruit decay in bothdecay incidence and decay index On the 20th day precooledfruits had 397 lower decay rate and 413 lower decayindex than control fruits respectively
34 Effects of Forced Air Precooling Treatment on ReactiveOxygen Species and Related Enzymes of MangoFruits during Storage
341 O2minus Production ere was no significant change ofO2minus production rate in mango fruits during the beginning ofstorage After 10 days rate of O2minus production in controlfruits increased rapidly and suddenly while that in pre-cooled fruits increased slightly On the 15th and 20th day rateof O2minus production in precooled fruits was only 678 and645 of control fruits respectively (Figure 7(a))
342 Malondialdehyde Content Figure 7(b) showed thatMDA content in control fruits increased rapidly at the first5 days of storage and then kept steady while MDA contentin precooled fruits increased steadily during the wholestorage On the 5th and 10th day MDA content in precooledfruits was only 661 and 802 of that in control fruits Inthe storage period MDA content of precooled fruits wasgradually close to the control At the end of the storage
Journal of Food Quality 5
period there was no signicant dierence between theMDAcontent of two groups
343 Superoxide Catalase Peroxidase and Ascorbic Per-oxidase Activities As shown in Figure 8 during the wholestorage period the activities of SOD CAT POD and APXin mango fruits showed a constant increase tendencyPrecooled fruits exhibited higher SOD and CAT activitiesin the entire storage period On the 20th day treated fruitshad 232 higher CAT activity and 27 higher SOD ac-tivity than control fruits respectively (Figures 8(a) and8(b))
Precooling treatment enhanced POD activity in mangofruits except on the 5th day of storage On the 15th and 20thday of storage precooled fruits had 236 and 105 higherPOD activity than control fruits respectively (Figure 8(c))At the beginning of storage precooled fruits showed higherAPX activity which was 1266 higher than the controlWhile at the end of storage precooling treatment had no
signicant incopyuence on APX activity in mango fruits(Figure 8(d))
344 Glutathione Content and Glutathione ReductaseActivity As shown in Figure 9(a) GSH content in mangofruits showed a gradually increase during rst 10 days andthen decreased slowly Precooled fruits had higher GSHcontent than control fruits during the whole storage On the10th and 15th day of storage treated fruits had 221 and127 higher GSH content than control fruits respectively
GR activity in mango fruits increased with the pro-longing of the storage time Precooled fruits had lower GRactivity than control fruits at earlier storage At the end of thestorage the GR activity in precooled fruits was slightlyhigher but the dierence was not signicant (Pgt 005Figure 9(b))
345 Polyphenoloxidase Activity As shown in Figure 10PPO activity in control fruits increased dramatically at
0
2
4
6
8
0 5 10 15 20
Chlo
roph
yll a
cont
ent
(mgmiddot
100g
ndash1middotF
W)
ControlPrecooling
Days of storage
(a)
Chlo
roph
yll a
cont
ent
(mgmiddot
100g
ndash1middotF
W)
ControlPrecooling
00
02
04
06
0 5 10 15 20Days of storage
(b)
Chlo
roph
yll b
cont
ent
(mgmiddot
100g
ndash1middotF
W)
ControlPrecooling
00
05
10
15
20
25
0 5 10 15 20Days of storage
(c)
Chlo
roph
yll b
cont
ent
(mgmiddot
100g
ndash1middotF
W)
ControlPrecooling
00
01
02
0 5 10 15 20Days of storage
(d)
Figure 3 Eects of forced air precooling treatment on chlorophyll a of peel (a) and copyesh (b) and chlorophyll b of mango fruit peel (c) and copyesh(d)
6 Journal of Food Quality
earlier storage and had a peak activity on the 5th day ofstorage after which PPO activity decreased and was keptstable PPO activity in precooled fruits was always at a lowerlevel On the 5th day and 20th day precooled fruits had 819and 674 lower PPO activity than control fruitsrespectively
4 Discussion
Mango fruits are a typical climacteric fruit and commonlyharvested at a green mature stage to prevent the postharvestloss [25] After harvest fruits begin to ripe with the char-acteristic changes on peel coloration textural softeningsugar maintenance suer from over softening and ripeningduring storage which result in postharvest quality de-terioration and short shelf-life [26] In this study the resultsshowed that precooling treatment could retard fruit soft-ening peel coloration accumulation of sugar and organicacid and disease development on mango fruits and all ofwhich were closely related to the maintenance of fruitripening [27]
04
05
06
07
08
09
10
0 5 10 15 20
Flav
onoi
ds co
nten
t (O
D32
5 gndash1
middotFW
)
Days of storage
ControlPrecooling
Figure 5 Eects of forced air precooling treatment on copyavonoidcontent
4
8
12
16
20
0 5 10 15 20
Tota
l sol
uble
solid
s (
)
ControlPrecooling
Days of storage
(a)
0
1
2
0 5 10 15 20
Titr
atab
le ac
idity
cont
ent (
)
ControlPrecooling
Days of storage
(b)
ControlPrecooling
02
03
04
05
06
0 5 10 15 20
Solu
ble s
ugar
cont
ent (
)
Days of storage
(c)
ControlPrecooling
00
02
04
06
08
0 5 10 15 20
Star
ch co
nten
t (
)
Days of storage
(d)
FIGURE 4 Eects of forced air precooling treatment on TSS (a) TA (b) soluble sugar (c) and starch (d) content
Journal of Food Quality 7
Firmness is an important parameter in postharveststorage and marketing Loss of rmness caused by degra-dation of cell wall and starch may result in physical damagesin transportation and fruit susceptibility to pathogen attacks[2] In this study precooled fruits showed higher rmnessduring the entire storage It is in coincidence with previousstudy on waxberry and black mulberry fruits [1] It indicatedthat precooling treatment could retard mango fruitrsquos soft-ening and ripening and it might be related to the decreasedrespiration in the early of storage During postharvest rip-ening the chlorophyll content in mango peel decreased andthe peel color changes from green to yellow [28] Usually thepeel color was considered as an important indicator of fruitmaturity and a critical parameter in fruit marketing [29] Inthis study precooled fruits showed a lower yellow index andblowast value than control fruits and it was closely related to
higher chlorophyll a and chlorophyll b content in mangofruits peel during the storage [13] However the pigment inmango copyesh was not incopyuenced by precooling treatmentFruit weight loss is an important postharvest parameterincopyuencing fruit storage quality shelf-life and economicvalue In the current study however precooling treatmentpromoted fruit weight loss in storage at might be becausethat precooling treatment speeded water transpiration onmango fruitrsquos surface and enhanced fruit water loss Forcedair precooling was done without humidied air leading tohigher weight loss
After harvest mango fruits showed high respiration rateand metabolism activity which accelerated the consumptionof nutritional compounds and fruit ripening With fruitripening SSC and soluble sugar increase because of poly-saccharide hydrolysis while starch a vital polysaccharide in
0
2
4
6
8
10
0 5 10 15 20Days of storage
ControlTreatment
Rate
of O
2ndash pro
duct
ion
(nm
olmiddotg
ndash1middotF
Wmiddotm
inndash1
)
(a)
ControlTreatment
005
010
015
0 5 10 15 20
MD
A co
nten
t (nm
olmiddotg
ndash1middotF
W )
Days of storage
(b)
Figure 7 Eects of forced air precooling treatment on Ominus2 production (a) and MDA content (b)
0
20
40
60
80
100
10 15 20
Dec
ay in
cide
nce (
)
Days of storage
ControlPrecooling
(a)
ControlPrecooling
0
1
2
3
4
10 15 20
Dec
ay se
verit
y (
)
Days of storage
(b)
Figure 6 Eects of forced air precooling treatment on decay incidence (a) and decay severity (b)
8 Journal of Food Quality
fruit decreases continuously [30] In the current studyprecooled fruits showed lower SSC and higher starch contentduring the entire storage It indicated precooling treatmentretarded the hydrolysis of polysaccharides to SSC Mean-while starch degradation is closely related with fruit soft-ening Inhibiting the degradation of starch to SSC alsocontributed to the fruit rmness maintenance [15] econtent of TA represents the concentration of organic acidin fruits Fruit respiration can promote organic acid con-sumption and reduce TA content [31] During storage thecontent of TA in mango fruits decreased rapidly and pre-cooling treatment inhibited the tendency e change ofSSC TA and starch content might be related to the delay inthe ripening process and reduction of respiration rate Incoincidence with the previous study on apricot [10] pre-cooling treatment enhanced copyavonoids content in mangofruits in the late stage of storage Flavonoids content is animportant indicator of fruitrsquos antioxidant capacity [32] and
precooling treatment might contribute to mango fruitsantioxidant capacities However possible mechanisms needto be studied further
With the prolonging of storage fruit resistance topathogen decreases because of ripening and softening anddecay happens e current study found that precoolingtreatment reduced decay on mango fruits including decayincidence and decay index (decay severity) which is similarto the study on green asparagus and broccoli [33] It ispossible because that precooling treatment retarded mangofruit ripening and maintained fruit resistance to postharvestpathogens
Although reactive oxygen species (ROS) was benecial tothe improvement of plant disease resistance excessive ROScan aect DNA replication and protein synthesis resultingin fruit senescence [34] According to free radical theorysenescence was a process of active oxygen metabolismdisorders and accumulation When the fruits are forced by
0
10
20
30
40
0 5 10 15 20
CAT
activ
ity (U
middotgndash1
middotFW
middotmin
ndash1)
ControlTreatment
Days of storage
(a)
ControlTreatment
Days of storage
50
55
60
0 5 10 15 20
SOD
activ
ity (U
middotgndash1
middotFW
)
(b)
ControlTreatment
0
200
400
600
0 5 10 15 20
POD
activ
ity (U
middotgndash1
middotFW
middotmin
ndash1)
Days of storage
(c)
ControlTreatment
0
100
200
300
400
500
0 5 10 15 20
APX
activ
ity (U
middotgndash1
middotFW
middotmin
ndash1)
Days of storage
(d)
Figure 8 Eects of forced air precooling treatment on CAT (a) SOD (b) POD (c) and APX (d) activity
Journal of Food Quality 9
outside stresses reactive oxygen species metabolism balanceis broken free radicals are accumulated in abundance andthe peroxidation of membrane lipid is improved or aggra-vated all of which induce the fruit senescence [13] O2minus is akind of reactive oxygen species with relatively high viru-lence playing an important role in horticultural plant rip-ening and senescence processes particularly in membranedeterioration [35] is study showed that the O2minus pro-duction rate in mango fruits increased rapidly at the end ofstorage leading to senescence of mango Precooling treat-ment inhibited the increase of O2minus production rate andsubsequent fruit senescence Moreover being as the productof membrane lipid peroxidation MDA was usually used toevaluate the degree of membrane damage [36] and lipidperoxidation [37] In this study MDA content was increasedrapidly during the later storage period and was always at ahigher levelis veried that the mango fruitrsquos cellulose was
peroxidated and the integrity of the cell membrane wasdestroyed
ere are many active oxygen removal systems in planttissue e excessive active oxygen was eliminated by dif-ferent antioxidant enzymes [13] O2minus can be transformedinto H2O2 by SOD in the plants is study found thatprecooling treatment enhanced the SOD activity of mangofruits during storage at might be why precooled fruit hadlower O2minus production rate than control fruits In additionwe also found that precooled fruits had higher CAT andPOD activities than control fruits We could include thatprecooled fruits had lower reactive oxygen species thancontrol fruits However there was no signicant dierenceof APX between the precooled fruits and control fruits in thisstudy is could be due to the higher activity of CAT andPOD in mango fruits and APX had not played a major partin elimination of H2O2 erefore the balance betweenSOD POD CAT and APX activities in plants is importantfor determining the steady-state levels of H2O2 and ROS[38]
Glutathione (GSH) is also a very important kind of theactive oxygen removal material [35] In plant tissue GSHcan reduce dehydroascorbic acid (DHA) to ascorbic acid(ASA) and ASA can eliminate H2O2 directly Glutathionereductase (GR) is the key enzyme involved in the GSHgeneration from oxidized glutathione (GSSC) [13 35] isstudy showed that precooled fruits had a higher GSHcontent and GR activity than control fruits during thestorage all of which contributed to the delay of fruit ripeningand senescence
Previous reports indicated that PPO was directly relatedto browning and decay Decrease in its activity would lead toan induced resistance to browning and decay [25] In normalcircumstances PPO usually exists in organelles membraneand cell membrane so the PPO activity is low [13]When thestructure of cell membrane is destroyed PPO is released andthe activity increases In this study the PPO activity in
20
40
60
80
0 5 10 15 20
GSH
cont
ent (
nmol
middotgndash1
middotFW
)
Days of storage
ControlTreatment
(a)
ControlTreatment
0
100
200
300
0 5 10 15 20
GR
activ
ity (U
middotgndash1
middotFW
middotmin
ndash1)
Days of storage
(b)
Figure 9 Eects of forced air precooling treatment on GSH content (a) and GR activity (b)
0
2
4
6
8
10
12
14
0 5 10 15 20
PPO
activ
ity (U
middotgndash1
middotFW
middotmin
ndash1)
Days of storage
ControlTreatment
Figure 10 Eects of forced air precooling treatment on PPOactivity
10 Journal of Food Quality
precooled fruits was always kept in a low level and thismight be because the precooling treatment enhanced theantioxidant defense capabilities and helped to maintain cellintegrity
5 Conclusion
Mango fruitrsquos quality was significantly improved by forcedair precooling treatment Precooling treatment delayed fruitripening and senescence with inhibition of ROS and en-hancement of active oxygen removal enzymes such as su-peroxide dismutase (SOD) catalase (CAT) peroxidase(POD) glutathione reductase (GR) and polyphenoloxidase(PPO) e firmness was maintained and fruit decay wasinhibited during storage ese results indicate that forcedair precooling treatment could maintain mango fruitrsquosquality by enhancing antioxidant activity and delaying fruitripening erefore it is suggested that mango fruits shouldbe precooled immediately after harvest for maintaining fruitquality and prolonging shelf-life
Data Availability
e data used to support the findings of this study areavailable from the corresponding author upon request
Conflicts of Interest
e authors declare that there are no conflicts of interestassociated with the publication of this manuscript
Acknowledgments
is research was supported by Support Project of High-Level Teachers in Beijing Municipal Universities in thePeriod of the 13th Five-Year Plan (CITampTCD201704037)Construction of Scientific Research Innovation ServiceAbility-Basic Scientific Research Operating Expense-FoodFeature Project (PXM2018_014213_000033) and SupportProject of High-Level Teachers in Beijing Municipal Uni-versities (IDHT20180506)
References
[1] Q Han H Gao H Chen X Fang and W Wu ldquoPrecoolingand ozone treatments affects postharvest quality of blackmulberry (Morus nigra) fruitsrdquo Food Chemistry vol 221pp 1947ndash1953 2017
[2] G M Cosme Silva W B Silva D B Medeiros et al ldquoechitosan affects severely the carbon metabolism in mango(Mangifera indica L cv Palmer) fruit during storagerdquo FoodChemistry vol 237 pp 372ndash378 2017
[3] J Li Q Li X J Lei et al ldquoEffects of wax coating on themoisture loss of cucumbers at different storage temperaturesrdquoJournal of food quality vol 2018 no 12 pp 1ndash6 2018
[4] H J Zhou Z W YE M S Su and J H Du ldquoEffects of lowtemperature and forced air precooling on precooling per-formance of different varieties of peach fruitsrdquo Storage ampProcess vol 15 pp 16ndash19 2015
[5] A Rab H Rehman I Haq M Sajid K Nawab and K AlildquoHarvest stages and pre-cooling influence the quality and
storage life of tomato fruitrdquo Journal Animal amp Plant Sciencevol 23 no 5 pp 1347ndash1357 2013
[6] M Zhou K H Ndeurumio L Zhao and Z Hu ldquoImpact ofprecooling and controlled-atmosphere storage on γ--aminobutyric acid (GABA) accumulation in longan (dimo-carpus longan lour) fruitrdquo Journal of Agricultural and FoodChemistry vol 64 no 33 pp 6443ndash6450 2016
[7] D Martinez-Romero S Castillo and D Valero ldquoForced aircooling applied before fruit handling to prevent mechanicaldamage of plums (Prunus salicina Lindl)rdquo Postharvest Biologyamp Technology vol 28 no 1 pp 135ndash142 2003
[8] H Nalbandi S Seiiedlou H R Ghasemzadeh andF Rangbar ldquoInnovative parallel airflow system for forced-aircooling of strawberriesrdquo Food and Bioproducts Processingvol 100 pp 440ndash449 2016
[9] J L OrsquoSullivan M J Ferrua R Love P VerbovenB Nicolaı and A East ldquoForced air cooling of polylinedhorticultural produce optimal cooling conditions andpackage designrdquo Postharvest Biology amp Technology vol 126pp 67ndash75 2017
[10] J Yan Y Song J Li and W Jiang ldquoForced-air precoolingtreatment enhanced antioxidant capacities of apricotsrdquoJournal of Food Processing and Preservation vol 42 no 1article e13320 2018
[11] M Jincy M Djanaguiraman P JeyakumarK S Subramanian S Jayasankar and G Paliyath ldquoInhibitionof phospholipase D enzyme activity through hexanal leads todelayed mango (Mangifera indica L) fruit ripening throughchanges in oxidants and antioxidant enzymes activityrdquo Sci-entia Horticulturae vol 218 pp 316ndash325 2017
[12] J Li G W Ma L Ma et al ldquoMultivariate analysis of fruitantioxidant activities of blackberry treated with 1-Methyl-cyclopropene or vacuum precoolingrdquo International Journal ofAnalytical Chemistry vol 2018 Article ID 2416461 5 pages2018
[13] P Sharma A B Jha R S Dubey andM Pessarakli ldquoReactiveoxygen species oxidative damage and antioxidative defensemechanism in plants under stressful conditionsrdquo Journal ofBotany vol 2012 Article ID 217037 26 pages 2012
[14] O Elloumi M Ghrab andM BenMimoun ldquoEffects of flowerbuds removal on seasonal starch storage and mobilization infruiting and non-fruiting branches of pistachio trees cvMateur under dry and warm climaterdquo Scientia Horticulturaevol 172 no 3 pp 19ndash25 2014
[15] K Liu J Liu H Li C Yuan J Zhong and Y Chen ldquoInfluenceof postharvest citric acid and chitosan coating treatment onripening attributes and expression of cell wall related genes incherimoya (Annona cherimola Mill) fruitrdquo Scientia Horti-culturae vol 198 no 10 pp 1ndash11 2016
[16] D M Hodges J M Delong C F Forney and R K PrangeldquoImproving the thiobarbituric acid-reactive-substances assayfor estimating lipid peroxidation in plant tissues containinganthocyanin and other interfering compoundsrdquo Plantavol 207 no 4 pp 604ndash611 1999
[17] J E Brehe andH B Burch ldquoEnzymatic assay for glutathionerdquoAnalytical Biochemistry vol 74 no 1 pp 189ndash197 1976
[18] D Prochazkova R K Sairam G C Srivastava andD V Singh ldquoOxidative stress and antioxidant activity as thebasis of senescence in maize leavesrdquo Plant Science vol 161no 4 pp 765ndash771 2001
[19] C Larrigaudiere I Lentheric J Puy and E Pinto ldquoBio-chemical characterisation of core browning and brown heartdisorders in pear bymultivariate analysisrdquo Postharvest Biologyand Technology vol 31 no 1 pp 29ndash39 2004
Journal of Food Quality 11
[20] S Naima M R Khan and S Maria ldquoAntioxidant activitytotal phenolic and total flavonoid contents of whole plantextracts Torilis leptophylla Lrdquo BMC Complementary and Al-ternative Medicine vol 12 no 1 p 221 2012
[21] Y Nakano and K Asada ldquoPurification of ascorbate peroxi-dase in spinach chloroplasts its inactivation in ascorbate-depleted medium and reactivation by monodehydroascorbateradicalrdquo Plant amp Cell Physiology vol 28 no 1 pp 131ndash1401987
[22] C H Foyer and B Halliwell ldquoe presence of glutathione andglutathione reductase in chloroplasts a proposed role inascorbic acid metabolismrdquo Planta vol 133 no 1 pp 21ndash251976
[23] F Zhu Z Yun Q Ma et al ldquoEffects of exogenous 24-epi-brassinolide treatment on postharvest quality and resistanceof Satsuma Mandarin (Citrus unshiu)rdquo Postharvest Biologyand Technology vol 100 pp 8ndash15 2015
[24] S Zhu and B Ma ldquoBenzothiadiazole- or methyl jasmonate-induced resistance toColletotrichum musaein harvested ba-nana fruit is related to elevated defense enzyme activitiesrdquolteJournal of Horticultural Science and Biotechnology vol 82no 4 pp 500ndash506 2007
[25] J-W Han J-P Qian C-J Zhao X-T Yang and B-L FanldquoMathematical modelling of cooling efficiency of ventilatedpackaging integral performance evaluationrdquo InternationalJournal of Heat andMass Transfer vol 111 pp 386ndash397 2017
[26] X Zheng L Ye T Jiang G Jing and J Li ldquoLimiting thedeterioration of mango fruit during storage at room tem-perature by oxalate treatmentrdquo Food Chemistry vol 130no 2 pp 279ndash285 2012
[27] J K Dhemre D P Waskar S D Masalkar andR S Gaikwad ldquoEffect of post-harvest treatments on shelf lifeand quality of mango cv Kesar in cool storage and ambientconditionsrdquo Agricultural Science Digest vol 25 no 2pp 79ndash84 2005
[28] M Fleancu ldquoCorrelations among some physiological pro-cesses in apple fruit during growing and maturation pro-cessesrdquo International Journal of Agriculture amp Biologyvol 8530 pp 9ndash4 2007
[29] H Vergara-Domınguez J J Rıos B Gandul-Rojas andM Roca ldquoChlorophyll catabolism in olive fruits (var Arbe-quina and Hojiblanca) during maturationrdquo Food Chemistryvol 212 pp 604ndash611 2016
[30] S S Zaharah and Z Singh ldquoPostharvest nitric oxide fumi-gation alleviates chilling injury delays fruit ripening andmaintains quality in cold-stored ldquoKensington Priderdquo mangordquoPostharvest Biology and Technology vol 60 no 3 pp 202ndash210 2011
[31] M Babalar M Asghari A Talaei and A Khosroshahi ldquoEffectof pre- and postharvest salicylic acid treatment on ethyleneproduction fungal decay and overall quality of Selva strawberryfruitrdquo Food Chemistry vol 105 no 2 pp 449ndash453 2007
[32] A Ali M K Ong and C F Forney ldquoEffect of ozone pre-conditioning on quality and antioxidant capacity of papayafruit during ambient storagerdquo Food Chemistry vol 142 no 2pp 19ndash26 2014
[33] X Wang S Gu and B Chen ldquoe mechanism of cholesterol-effect on the quality of green asparagus (Asparagus officinalisL) spears during low temperature storagerdquo Scientia Horti-culturae vol 231 pp 36ndash42 2018
[34] M Sivapriya and S Leela ldquoIsolation and purification of anovel antioxidant protein from the water extract of Sundakai(Solanum torvum) seedsrdquo Food Chemistry vol 104 no 2pp 510ndash517 2007
[35] F V Breusegem E Vranova J F Dat and D Inze ldquoe roleof active oxygen species in plant signal transductionrdquo PlantScience vol 161 no 3 pp 405ndash414 2001
[36] L M Segal and R A Wilson ldquoReactive oxygen speciesmetabolism and plant-fungal interactionsrdquo Fungal Geneticsand Biology vol 110 pp 1ndash9 2018
[37] Y Wang X Xie and L E Long ldquoe effect of postharvestcalcium application in hydro-cooling water on tissue calciumcontent biochemical changes and quality attributes of sweetcherry fruitrdquo Food Chemistry vol 160 no 11 pp 22ndash30 2014
[38] Y Imahori J Bai and E Baldwin ldquoAntioxidative responses ofripe tomato fruit to postharvest chilling and heating treat-mentsrdquo Scientia Horticulturae vol 198 no 75 pp 398ndash4062016
Excessive production of reactive oxygen species (ROS) suchas O2minus and H2O2 can cause progressive oxidative damageand ultimately cell death accelerating fruit senescence [12]Fruits also produce a natural defense system scavengingROS enhancing membrane stability and protecting fruitsfrom senescence deterioration e antioxidant enzymesystem includes superoxide dismutase (SOD) peroxidase(POD) catalase (CAT) ascorbate peroxidase (APX) andglutathione reductase (GR) Mango fruits also include fla-vonoids which could eliminate O2minus and inhibit senescence ofplants [13]
So far there have been fewer reports on the changes inquality and physiological metabolism ofmango fruits treatedwith forced air precooling In this study the effect of forcedair precooling on postharvest qualities of mango fruitsduring the storage period was investigated e changes ofreactive oxygen species and eliminate system were alsodiscussed
2 Materials and Methods
Tainongmango fruits (Mangifera indica L cv Tainong) wereharvested from a nearby orchard and transported to thelaboratory immediately e maturity of the fruit wasindicted by mature green Fruits that were uniform in sizecolor shape and free of mechanical damage and pathogeninfection were selected for experiments Seventy-two fruitswere placed in a 45 cmtimes 30 cmtimes 30 cm plastic box with 20whole area Each box was placed in a tube which containedan exhaust fan Fruits were forced air precooled with 1ms0degC air for 30min until the central temperature reached 13degCand then stored at 13degC and 85sim95 relative humidity(RH) e control fruits were directly stored at 13degC and85sim95 RH e experiment contained two hundred andseventy fruits Fruit quality was evaluated and fruit flesh andpeel were sampled on the 0th 5th 10th 15th and 20th day ofstorage
211 Weight Loss Weight loss was determined by weighingfruit at harvest (initial weight) and every evaluation time andexpressed as percentage loss of the initial weight
212 Firmness Firmness was measured by using a Boschpenetrometer (Model FT 327) at two opposite points on theequatorial region of mango fruits
213 Color e yellow index of fruit peel was visuallyevaluated and scored on a 0 to 4 scale from green to yellowe yellow index was calculated using the following formula
yellow index() 1 times n1 + 2 times n2 + 3 times n3 + 4 times n4
4 times n
times 100
(1)
where n1 to n4 represent the number of fruits in differentscores 1 to 4 respectively and n represents the total numberof fruit
Fruit peel color was measured by using a chromameter(ADCI-60C China) at two opposite points on the equatorialregion of mango fruits and recorded ldquoLlowastrdquo ldquoalowastrdquo and ldquoblowastrdquovalue
214 Pigment Contents For determination of chlorophyll aand chlorophyll b contents 4ml of 90 acetone was addedinto 10 g of mango flesh (05 g peel) and then centrifuged at10000times g for 20min at 4degC Absorbance of the supernatantwas measured at 663 nm and 645 nm
For all external quality evaluation there were threereplicates in each treatment with one replicate containingten fruits
22 Internal Quality Evaluation
221 Total Soluble Solid Content Total soluble solids (TSSs)content was expressed as using a digital refractometer(Atago PAL-1 Japan)
222 Titratable Acidity Content Titratable acidity (TA)content was titrated by NaOH
223 Soluble Sugar Content For soluble sugar contentdetermination 3 g of fruit flesh was mixed with 60ml ofdistilled water e mixture was heated in a boiling waterbath for 20min and then centrifuged at 10000times g for15min Finally the abstained supernatant was used forsoluble sugar analysis Soluble solid content (SSC) wasmeasured by using an Atago digital refractometer (PAL-1Japan)
224 Starch Content According to Elloumi et al [14] thephenol-sulfuric acid method was used to determine thestarch content 10 g fruit flesh was added into 50ml ofdistilled water and placed in a boiling water bath for 20mine residue was shifted to the graduate test tube added withdistilled water to 10ml and boiled for another 15minen20ml of 96M perchloric acid was added to the graduatedtest tube to extract for 6 h After centrifugation at 10000times gfor 15min the supernatant was collected for starch contentanalysis Starch content was measured by using a spectro-photometer (PerkinElmer Lambda 35 UK)
225 Flavonoid Content 10 g fruit flesh was added in 4mlof 1 HCl-methyl alcohol extracted for 2 h and centrifugedat 10000times g at 4degC for 20min e absorbance of the
2 Journal of Food Quality
supernatant was measured at 325 nm e content of theflavonoids was expressed as OD325g at 325 nm by using aspectrophotometer (PerkinElmer Lambda 35 UK)
For all the internal quality evaluations three replicateswere performed for each treatment and ten fruits were usedfor each replicate
226 Decay Evaluation e decay rate of fruit was visuallyevaluated Fruits with visible disease development wereconsidered decayed and the percentage of decay fruits wasused for expressing decay rate
decay rate total number of decayed fruits
total number of fruitstimes 100 (2)
e decay index of fruit was visually evaluated andscored on from 0 to 4 ere were three replicates in eachtreatment and each replicate contained thirty fruits
23 Reactive Oxygen Species and Related Enzymes
231 O2minus Production Rate According to Liu et al [15] fruitflesh (20 g) was added with 4ml of 100mM phosphatebuffer (pH 78 containing 2 PVPP and precooled at 4degC)and grinded on ice After centrifugation at 10000times g at 4degCfor 20min the supernatant was collected for the mea-surement of O2minus production rate e KNO2 solution wasused to make the standard curve e O2minus production ratewas expressed as nmolmiddotgminus1middotFWmiddotminminus1
232 Malondialdehyde Content According to Hodges et al[16] 10 g fruit flesh was added with 10 (wv) TCA solutionthat was precooled at 4degC After grinding and centrifugationat 10000times g at 4degC for 20min the supernatant was used forMDA measurement by using a spectrophotometer (Perki-nElmer Lambda 35 UK) e MDA content was calculatedusing the following formula
CMDAμmolL
1113888 1113889 645 times OD532 minusOD600( 1113857minus 056 times OD450
(3)
233 Glutathione Content According to Brehe and Burch[17] fruit flesh (10 g) was homogenized on ice with 3ml of5 (wv) TCA solution that contained 5mMEDTA-Na2 andwas precooled at 4degC After centrifugation at 10000times g at4degC for 20min the supernatant was collected for GSHmeasurement GSH content was expressed as nmolmiddotgminus1middotFW
234 Superoxide Catalase Ascorbic Peroxidase and Glu-tathione Reductase Activities Superoxide catalase ascorbicperoxidase and glutathione reductase activities wereexpressed as 001 changes in absorbance at correspondingnm per minute per g flesh tissue by using a spectropho-tometer (PerkinElmer Lambda 35 UK)
Superoxide (SOD) activity was determined according toProchazkova et al [18] and Larrigaudiere et al [19] e
amount of enzyme that inhibited 50 of NBTphotochemicalreduction was defined as a SOD activity unit
Catalase (CAT) activity was determined according toNaima et al [20] and expressed as 001 change in absorbanceat 240 nm per minute per g flesh tissue
Ascorbic peroxidase (APX) activity was determinedaccording to Nakano and Asada [21] and expressed as 001changes in absorbance at 290 nm per minute per g fleshtissue
Glutathione reductase (GR) activity was determinedaccording to Foyer and Halliwell [22] and expressed as 001changes in absorbance at 340 nm per minute per g of fleshtissue
235 Peroxidase and Polyphenoloxidase ActivityPeroxidase (POD) activity was determined according to Zhuet al [23] 500 μL of 05 (vv) guaiacol and 15mL of 50mMacetate buffer (pH 55) were added into 500 μL enzymeextraction e reaction started when 500 μL of0059MH2O2 was added e enzyme activity unit wasdetermined by monitoring the increase of absorbance at470 nm per min e enzyme activity was expressed asUmiddotgminus1middotFWminus1 Polyphenoloxidase (PPO) activity was de-termined according to Zhu and Ma [24] One PPO activityunit was defined as 1 change in absorbance at 420 nm perminute per g of flesh tissue by using a spectrophotometer(PerkinElmer Lambda 35 UK)
24 Statistical Analysis SPSS 110 for Windows (SPSS IncChicago IL) was used for data collection and analysis with aone-way analysis of variance (ANOVA) Duncanrsquos multiplecomparison was used to separate means at the 5 level
3 Results
31 Effects of Forced Air Precooling on External Quality ofMango Fruits during Storage
311 Firmness Mango fruits firmness decreased dramati-cally after harvest while precooling treatment retarded thedecrease e precooled fruit had higher firmness than thecontrol group during the whole period On the 10th day and15th day precooled fruits had 333 and 624 higherfirmness than control fruits respectively (Figure 1(a))
312 Weight Loss As shown in Figure 1(b) weight loss ofmango fruits increased steadily and precooling treatmentincreased fruit weight loss slightly On the 20th day ofstorage precooled fruits had 22 higher weight loss thancontrol fruits
313 Color As shown in Figure 2(a) the yellow index inmango fruits was increased steadily during storage whileprecooling treatment inhibited the color change On the 10thday and 15th day the precooled fruits had 233 and 145 alower yellow index than control fruits respectively e
Journal of Food Quality 3
0
1
2
3
4
0 5 10 15 20
Firm
ness
(N)
Days of storage
ControlPrecooling
(a)
0
2
4
6
8
5 10 15 20
Wei
ght l
oss (
)
Days of storage
ControlPrecooling
(b)
Figure 1 Eects of forced air precooling treatment on rmness (a) and weight loss (b)
Days of storage
0
20
40
60
80
100
10 15 20
Yello
w in
cide
nce (
)
ControlTreatment
(a)
40
50
60
70
80
0 5 10 15 20
Llowast
ControlPrecooling
Days of storage
(b)
ndash30
ndash20
ndash10
0
10
20
0 5 10 15 20
alowast
Days of storage
ControlPrecooling
(c)
30
40
50
60
70
0 5 10 15 20
blowast
Days of storage
ControlPrecooling
(d)
FIGURE 2 Eects of forced air precooling treatment on the (a) yellow index (b) Llowast value (c) alowast value and (d) blowast value
4 Journal of Food Quality
difference between precooled and control fruit was notsignificant at the end of storage
Llowast value from low to high indicates that the lightnessincreases Llowast value of mango fruits peel increased with theprolonging of the storage time Llowast value in precooled fruitswas lower than control fruits during the entire storageperiod On the 10th day the Llowast value of precooled fruits was115 lower than that of control fruits (Figure 2(b)) alowast valuefrom negative to positive represents that the color changesfrom green to red and blowast was from blue to yellow With theextension of storage alowast and blowast values of mango fruits peelwere all increased steadily which showed that the peel colorwas changing from green to yellow Precooling treatmentretarded the increase of alowast and blowast during the beginning ofthe storage On the 10th day precooled fruits had 478lower alowast and 149 lower blowast than that of control fruitsrespectively (Plt 005) e differences between precooledand control fruits were not significant at the end of storage(Figures 2(c) and 2(d))
314 Pigment Content Figure 3 showed pigment changes inmango fruit flesh and peel With the ripening of mangofruits chlorophyll a in mango fruits peel decreased dra-matically and the decrease of control fruits was higher thanprecooled fruits On the 20th day of storage precooled fruitspeel had 84 higher chlorophyll a than control fruits(Figure 3(a)) Chlorophyll a in mango fruits flesh was alsodecreased dramatically On the 10th day precooled fruitsfresh had a significantly higher level of chlorophyll a thanthat of control fruits At other times there was no significantdifference (Figure 3(b))
e change tendency of chlorophyll b in mango fruitspeel was similar to chlorophyll a and precooling treatmentalso retarded chlorophyll b reduction On the 15th and 20thday of storage precooled fruits peel had 188 and 200higher chlorophyll b than that of control fruits re-spectively (Figure 3(c)) However there was no significantdifference in chlorophyll b between precooled fruitsflesh and control fruits flesh during the storage period(Figure 3(d))
32 Effects of Forced Air Precooling on Internal Quality ofMango Fruits during Storage
321 Total Soluble Solids As shown in Figure 4(a) TSS ofcontrol fruits increased during the first 15 days and thendecreased Precooling treatment retarded the increase ofTSS and there was no decrease until the end of storageerefore on the 20th day of storage the TSS in precooledfruits was 116 higher than the control
322 Titratable Acidity Figure 4(b) showed the changes ofTA content in mango fruits during storage TA in mangofruits changed slightly during first 10 days after which TAdecreased rapidly Precooled fruits exhibited less decreasecompared to the control On the 15th day precooled fruitshad 395 higher TA content than control fruits
323 Soluble Sugar Content Soluble sugar content ofmango fruits in both precooled fruits and control fruitsincreased steadily with the increase of storage time At thebeginning of storage soluble sugar content in precooledfruits was slightly lower than that of control fruits At the endof the storage however soluble sugar content in precooledfruits was slightly higher than that of controls fruit But therewas no significant difference between the two groups(Figure 4(c))
324 Starch Content Figure 4(d) showed that starchcontent decreased continuously during the whole storageperiod On the 20th day starch content was only 25 of theinitial value Precooling treatment delayed the decrease ofstarch content during the beginning of the storage periodOn the 5th 10th and 15th precooled fruits had 273 223and 377 higher starch content than the control grouprespectively
325 Flavonoid Content As shown in Figure 5 flavonoidscontent was decreased in both precooled and control fruitsand then increased slightly at the first 5 days Flavonoid inprecooled fruits increased more rapidly than that in thecontrol On the 10th 15th and 20th day precooled fruits had103 112 and 61 higher flavonoids content thancontrol respectively
33 Effects of Forced Air Precooling Treatment on Decay In-cidence and Decay Severity of Mango Fruits during StorageDecay incidence and decay severity of mango fruits that werestored at 13degC and 85sim95 RH was shown in Figures 6(a)and 6(b) Precooling treatment decreased fruit decay in bothdecay incidence and decay index On the 20th day precooledfruits had 397 lower decay rate and 413 lower decayindex than control fruits respectively
34 Effects of Forced Air Precooling Treatment on ReactiveOxygen Species and Related Enzymes of MangoFruits during Storage
341 O2minus Production ere was no significant change ofO2minus production rate in mango fruits during the beginning ofstorage After 10 days rate of O2minus production in controlfruits increased rapidly and suddenly while that in pre-cooled fruits increased slightly On the 15th and 20th day rateof O2minus production in precooled fruits was only 678 and645 of control fruits respectively (Figure 7(a))
342 Malondialdehyde Content Figure 7(b) showed thatMDA content in control fruits increased rapidly at the first5 days of storage and then kept steady while MDA contentin precooled fruits increased steadily during the wholestorage On the 5th and 10th day MDA content in precooledfruits was only 661 and 802 of that in control fruits Inthe storage period MDA content of precooled fruits wasgradually close to the control At the end of the storage
Journal of Food Quality 5
period there was no signicant dierence between theMDAcontent of two groups
343 Superoxide Catalase Peroxidase and Ascorbic Per-oxidase Activities As shown in Figure 8 during the wholestorage period the activities of SOD CAT POD and APXin mango fruits showed a constant increase tendencyPrecooled fruits exhibited higher SOD and CAT activitiesin the entire storage period On the 20th day treated fruitshad 232 higher CAT activity and 27 higher SOD ac-tivity than control fruits respectively (Figures 8(a) and8(b))
Precooling treatment enhanced POD activity in mangofruits except on the 5th day of storage On the 15th and 20thday of storage precooled fruits had 236 and 105 higherPOD activity than control fruits respectively (Figure 8(c))At the beginning of storage precooled fruits showed higherAPX activity which was 1266 higher than the controlWhile at the end of storage precooling treatment had no
signicant incopyuence on APX activity in mango fruits(Figure 8(d))
344 Glutathione Content and Glutathione ReductaseActivity As shown in Figure 9(a) GSH content in mangofruits showed a gradually increase during rst 10 days andthen decreased slowly Precooled fruits had higher GSHcontent than control fruits during the whole storage On the10th and 15th day of storage treated fruits had 221 and127 higher GSH content than control fruits respectively
GR activity in mango fruits increased with the pro-longing of the storage time Precooled fruits had lower GRactivity than control fruits at earlier storage At the end of thestorage the GR activity in precooled fruits was slightlyhigher but the dierence was not signicant (Pgt 005Figure 9(b))
345 Polyphenoloxidase Activity As shown in Figure 10PPO activity in control fruits increased dramatically at
0
2
4
6
8
0 5 10 15 20
Chlo
roph
yll a
cont
ent
(mgmiddot
100g
ndash1middotF
W)
ControlPrecooling
Days of storage
(a)
Chlo
roph
yll a
cont
ent
(mgmiddot
100g
ndash1middotF
W)
ControlPrecooling
00
02
04
06
0 5 10 15 20Days of storage
(b)
Chlo
roph
yll b
cont
ent
(mgmiddot
100g
ndash1middotF
W)
ControlPrecooling
00
05
10
15
20
25
0 5 10 15 20Days of storage
(c)
Chlo
roph
yll b
cont
ent
(mgmiddot
100g
ndash1middotF
W)
ControlPrecooling
00
01
02
0 5 10 15 20Days of storage
(d)
Figure 3 Eects of forced air precooling treatment on chlorophyll a of peel (a) and copyesh (b) and chlorophyll b of mango fruit peel (c) and copyesh(d)
6 Journal of Food Quality
earlier storage and had a peak activity on the 5th day ofstorage after which PPO activity decreased and was keptstable PPO activity in precooled fruits was always at a lowerlevel On the 5th day and 20th day precooled fruits had 819and 674 lower PPO activity than control fruitsrespectively
4 Discussion
Mango fruits are a typical climacteric fruit and commonlyharvested at a green mature stage to prevent the postharvestloss [25] After harvest fruits begin to ripe with the char-acteristic changes on peel coloration textural softeningsugar maintenance suer from over softening and ripeningduring storage which result in postharvest quality de-terioration and short shelf-life [26] In this study the resultsshowed that precooling treatment could retard fruit soft-ening peel coloration accumulation of sugar and organicacid and disease development on mango fruits and all ofwhich were closely related to the maintenance of fruitripening [27]
04
05
06
07
08
09
10
0 5 10 15 20
Flav
onoi
ds co
nten
t (O
D32
5 gndash1
middotFW
)
Days of storage
ControlPrecooling
Figure 5 Eects of forced air precooling treatment on copyavonoidcontent
4
8
12
16
20
0 5 10 15 20
Tota
l sol
uble
solid
s (
)
ControlPrecooling
Days of storage
(a)
0
1
2
0 5 10 15 20
Titr
atab
le ac
idity
cont
ent (
)
ControlPrecooling
Days of storage
(b)
ControlPrecooling
02
03
04
05
06
0 5 10 15 20
Solu
ble s
ugar
cont
ent (
)
Days of storage
(c)
ControlPrecooling
00
02
04
06
08
0 5 10 15 20
Star
ch co
nten
t (
)
Days of storage
(d)
FIGURE 4 Eects of forced air precooling treatment on TSS (a) TA (b) soluble sugar (c) and starch (d) content
Journal of Food Quality 7
Firmness is an important parameter in postharveststorage and marketing Loss of rmness caused by degra-dation of cell wall and starch may result in physical damagesin transportation and fruit susceptibility to pathogen attacks[2] In this study precooled fruits showed higher rmnessduring the entire storage It is in coincidence with previousstudy on waxberry and black mulberry fruits [1] It indicatedthat precooling treatment could retard mango fruitrsquos soft-ening and ripening and it might be related to the decreasedrespiration in the early of storage During postharvest rip-ening the chlorophyll content in mango peel decreased andthe peel color changes from green to yellow [28] Usually thepeel color was considered as an important indicator of fruitmaturity and a critical parameter in fruit marketing [29] Inthis study precooled fruits showed a lower yellow index andblowast value than control fruits and it was closely related to
higher chlorophyll a and chlorophyll b content in mangofruits peel during the storage [13] However the pigment inmango copyesh was not incopyuenced by precooling treatmentFruit weight loss is an important postharvest parameterincopyuencing fruit storage quality shelf-life and economicvalue In the current study however precooling treatmentpromoted fruit weight loss in storage at might be becausethat precooling treatment speeded water transpiration onmango fruitrsquos surface and enhanced fruit water loss Forcedair precooling was done without humidied air leading tohigher weight loss
After harvest mango fruits showed high respiration rateand metabolism activity which accelerated the consumptionof nutritional compounds and fruit ripening With fruitripening SSC and soluble sugar increase because of poly-saccharide hydrolysis while starch a vital polysaccharide in
0
2
4
6
8
10
0 5 10 15 20Days of storage
ControlTreatment
Rate
of O
2ndash pro
duct
ion
(nm
olmiddotg
ndash1middotF
Wmiddotm
inndash1
)
(a)
ControlTreatment
005
010
015
0 5 10 15 20
MD
A co
nten
t (nm
olmiddotg
ndash1middotF
W )
Days of storage
(b)
Figure 7 Eects of forced air precooling treatment on Ominus2 production (a) and MDA content (b)
0
20
40
60
80
100
10 15 20
Dec
ay in
cide
nce (
)
Days of storage
ControlPrecooling
(a)
ControlPrecooling
0
1
2
3
4
10 15 20
Dec
ay se
verit
y (
)
Days of storage
(b)
Figure 6 Eects of forced air precooling treatment on decay incidence (a) and decay severity (b)
8 Journal of Food Quality
fruit decreases continuously [30] In the current studyprecooled fruits showed lower SSC and higher starch contentduring the entire storage It indicated precooling treatmentretarded the hydrolysis of polysaccharides to SSC Mean-while starch degradation is closely related with fruit soft-ening Inhibiting the degradation of starch to SSC alsocontributed to the fruit rmness maintenance [15] econtent of TA represents the concentration of organic acidin fruits Fruit respiration can promote organic acid con-sumption and reduce TA content [31] During storage thecontent of TA in mango fruits decreased rapidly and pre-cooling treatment inhibited the tendency e change ofSSC TA and starch content might be related to the delay inthe ripening process and reduction of respiration rate Incoincidence with the previous study on apricot [10] pre-cooling treatment enhanced copyavonoids content in mangofruits in the late stage of storage Flavonoids content is animportant indicator of fruitrsquos antioxidant capacity [32] and
precooling treatment might contribute to mango fruitsantioxidant capacities However possible mechanisms needto be studied further
With the prolonging of storage fruit resistance topathogen decreases because of ripening and softening anddecay happens e current study found that precoolingtreatment reduced decay on mango fruits including decayincidence and decay index (decay severity) which is similarto the study on green asparagus and broccoli [33] It ispossible because that precooling treatment retarded mangofruit ripening and maintained fruit resistance to postharvestpathogens
Although reactive oxygen species (ROS) was benecial tothe improvement of plant disease resistance excessive ROScan aect DNA replication and protein synthesis resultingin fruit senescence [34] According to free radical theorysenescence was a process of active oxygen metabolismdisorders and accumulation When the fruits are forced by
0
10
20
30
40
0 5 10 15 20
CAT
activ
ity (U
middotgndash1
middotFW
middotmin
ndash1)
ControlTreatment
Days of storage
(a)
ControlTreatment
Days of storage
50
55
60
0 5 10 15 20
SOD
activ
ity (U
middotgndash1
middotFW
)
(b)
ControlTreatment
0
200
400
600
0 5 10 15 20
POD
activ
ity (U
middotgndash1
middotFW
middotmin
ndash1)
Days of storage
(c)
ControlTreatment
0
100
200
300
400
500
0 5 10 15 20
APX
activ
ity (U
middotgndash1
middotFW
middotmin
ndash1)
Days of storage
(d)
Figure 8 Eects of forced air precooling treatment on CAT (a) SOD (b) POD (c) and APX (d) activity
Journal of Food Quality 9
outside stresses reactive oxygen species metabolism balanceis broken free radicals are accumulated in abundance andthe peroxidation of membrane lipid is improved or aggra-vated all of which induce the fruit senescence [13] O2minus is akind of reactive oxygen species with relatively high viru-lence playing an important role in horticultural plant rip-ening and senescence processes particularly in membranedeterioration [35] is study showed that the O2minus pro-duction rate in mango fruits increased rapidly at the end ofstorage leading to senescence of mango Precooling treat-ment inhibited the increase of O2minus production rate andsubsequent fruit senescence Moreover being as the productof membrane lipid peroxidation MDA was usually used toevaluate the degree of membrane damage [36] and lipidperoxidation [37] In this study MDA content was increasedrapidly during the later storage period and was always at ahigher levelis veried that the mango fruitrsquos cellulose was
peroxidated and the integrity of the cell membrane wasdestroyed
ere are many active oxygen removal systems in planttissue e excessive active oxygen was eliminated by dif-ferent antioxidant enzymes [13] O2minus can be transformedinto H2O2 by SOD in the plants is study found thatprecooling treatment enhanced the SOD activity of mangofruits during storage at might be why precooled fruit hadlower O2minus production rate than control fruits In additionwe also found that precooled fruits had higher CAT andPOD activities than control fruits We could include thatprecooled fruits had lower reactive oxygen species thancontrol fruits However there was no signicant dierenceof APX between the precooled fruits and control fruits in thisstudy is could be due to the higher activity of CAT andPOD in mango fruits and APX had not played a major partin elimination of H2O2 erefore the balance betweenSOD POD CAT and APX activities in plants is importantfor determining the steady-state levels of H2O2 and ROS[38]
Glutathione (GSH) is also a very important kind of theactive oxygen removal material [35] In plant tissue GSHcan reduce dehydroascorbic acid (DHA) to ascorbic acid(ASA) and ASA can eliminate H2O2 directly Glutathionereductase (GR) is the key enzyme involved in the GSHgeneration from oxidized glutathione (GSSC) [13 35] isstudy showed that precooled fruits had a higher GSHcontent and GR activity than control fruits during thestorage all of which contributed to the delay of fruit ripeningand senescence
Previous reports indicated that PPO was directly relatedto browning and decay Decrease in its activity would lead toan induced resistance to browning and decay [25] In normalcircumstances PPO usually exists in organelles membraneand cell membrane so the PPO activity is low [13]When thestructure of cell membrane is destroyed PPO is released andthe activity increases In this study the PPO activity in
20
40
60
80
0 5 10 15 20
GSH
cont
ent (
nmol
middotgndash1
middotFW
)
Days of storage
ControlTreatment
(a)
ControlTreatment
0
100
200
300
0 5 10 15 20
GR
activ
ity (U
middotgndash1
middotFW
middotmin
ndash1)
Days of storage
(b)
Figure 9 Eects of forced air precooling treatment on GSH content (a) and GR activity (b)
0
2
4
6
8
10
12
14
0 5 10 15 20
PPO
activ
ity (U
middotgndash1
middotFW
middotmin
ndash1)
Days of storage
ControlTreatment
Figure 10 Eects of forced air precooling treatment on PPOactivity
10 Journal of Food Quality
precooled fruits was always kept in a low level and thismight be because the precooling treatment enhanced theantioxidant defense capabilities and helped to maintain cellintegrity
5 Conclusion
Mango fruitrsquos quality was significantly improved by forcedair precooling treatment Precooling treatment delayed fruitripening and senescence with inhibition of ROS and en-hancement of active oxygen removal enzymes such as su-peroxide dismutase (SOD) catalase (CAT) peroxidase(POD) glutathione reductase (GR) and polyphenoloxidase(PPO) e firmness was maintained and fruit decay wasinhibited during storage ese results indicate that forcedair precooling treatment could maintain mango fruitrsquosquality by enhancing antioxidant activity and delaying fruitripening erefore it is suggested that mango fruits shouldbe precooled immediately after harvest for maintaining fruitquality and prolonging shelf-life
Data Availability
e data used to support the findings of this study areavailable from the corresponding author upon request
Conflicts of Interest
e authors declare that there are no conflicts of interestassociated with the publication of this manuscript
Acknowledgments
is research was supported by Support Project of High-Level Teachers in Beijing Municipal Universities in thePeriod of the 13th Five-Year Plan (CITampTCD201704037)Construction of Scientific Research Innovation ServiceAbility-Basic Scientific Research Operating Expense-FoodFeature Project (PXM2018_014213_000033) and SupportProject of High-Level Teachers in Beijing Municipal Uni-versities (IDHT20180506)
References
[1] Q Han H Gao H Chen X Fang and W Wu ldquoPrecoolingand ozone treatments affects postharvest quality of blackmulberry (Morus nigra) fruitsrdquo Food Chemistry vol 221pp 1947ndash1953 2017
[2] G M Cosme Silva W B Silva D B Medeiros et al ldquoechitosan affects severely the carbon metabolism in mango(Mangifera indica L cv Palmer) fruit during storagerdquo FoodChemistry vol 237 pp 372ndash378 2017
[3] J Li Q Li X J Lei et al ldquoEffects of wax coating on themoisture loss of cucumbers at different storage temperaturesrdquoJournal of food quality vol 2018 no 12 pp 1ndash6 2018
[4] H J Zhou Z W YE M S Su and J H Du ldquoEffects of lowtemperature and forced air precooling on precooling per-formance of different varieties of peach fruitsrdquo Storage ampProcess vol 15 pp 16ndash19 2015
[5] A Rab H Rehman I Haq M Sajid K Nawab and K AlildquoHarvest stages and pre-cooling influence the quality and
storage life of tomato fruitrdquo Journal Animal amp Plant Sciencevol 23 no 5 pp 1347ndash1357 2013
[6] M Zhou K H Ndeurumio L Zhao and Z Hu ldquoImpact ofprecooling and controlled-atmosphere storage on γ--aminobutyric acid (GABA) accumulation in longan (dimo-carpus longan lour) fruitrdquo Journal of Agricultural and FoodChemistry vol 64 no 33 pp 6443ndash6450 2016
[7] D Martinez-Romero S Castillo and D Valero ldquoForced aircooling applied before fruit handling to prevent mechanicaldamage of plums (Prunus salicina Lindl)rdquo Postharvest Biologyamp Technology vol 28 no 1 pp 135ndash142 2003
[8] H Nalbandi S Seiiedlou H R Ghasemzadeh andF Rangbar ldquoInnovative parallel airflow system for forced-aircooling of strawberriesrdquo Food and Bioproducts Processingvol 100 pp 440ndash449 2016
[9] J L OrsquoSullivan M J Ferrua R Love P VerbovenB Nicolaı and A East ldquoForced air cooling of polylinedhorticultural produce optimal cooling conditions andpackage designrdquo Postharvest Biology amp Technology vol 126pp 67ndash75 2017
[10] J Yan Y Song J Li and W Jiang ldquoForced-air precoolingtreatment enhanced antioxidant capacities of apricotsrdquoJournal of Food Processing and Preservation vol 42 no 1article e13320 2018
[11] M Jincy M Djanaguiraman P JeyakumarK S Subramanian S Jayasankar and G Paliyath ldquoInhibitionof phospholipase D enzyme activity through hexanal leads todelayed mango (Mangifera indica L) fruit ripening throughchanges in oxidants and antioxidant enzymes activityrdquo Sci-entia Horticulturae vol 218 pp 316ndash325 2017
[12] J Li G W Ma L Ma et al ldquoMultivariate analysis of fruitantioxidant activities of blackberry treated with 1-Methyl-cyclopropene or vacuum precoolingrdquo International Journal ofAnalytical Chemistry vol 2018 Article ID 2416461 5 pages2018
[13] P Sharma A B Jha R S Dubey andM Pessarakli ldquoReactiveoxygen species oxidative damage and antioxidative defensemechanism in plants under stressful conditionsrdquo Journal ofBotany vol 2012 Article ID 217037 26 pages 2012
[14] O Elloumi M Ghrab andM BenMimoun ldquoEffects of flowerbuds removal on seasonal starch storage and mobilization infruiting and non-fruiting branches of pistachio trees cvMateur under dry and warm climaterdquo Scientia Horticulturaevol 172 no 3 pp 19ndash25 2014
[15] K Liu J Liu H Li C Yuan J Zhong and Y Chen ldquoInfluenceof postharvest citric acid and chitosan coating treatment onripening attributes and expression of cell wall related genes incherimoya (Annona cherimola Mill) fruitrdquo Scientia Horti-culturae vol 198 no 10 pp 1ndash11 2016
[16] D M Hodges J M Delong C F Forney and R K PrangeldquoImproving the thiobarbituric acid-reactive-substances assayfor estimating lipid peroxidation in plant tissues containinganthocyanin and other interfering compoundsrdquo Plantavol 207 no 4 pp 604ndash611 1999
[17] J E Brehe andH B Burch ldquoEnzymatic assay for glutathionerdquoAnalytical Biochemistry vol 74 no 1 pp 189ndash197 1976
[18] D Prochazkova R K Sairam G C Srivastava andD V Singh ldquoOxidative stress and antioxidant activity as thebasis of senescence in maize leavesrdquo Plant Science vol 161no 4 pp 765ndash771 2001
[19] C Larrigaudiere I Lentheric J Puy and E Pinto ldquoBio-chemical characterisation of core browning and brown heartdisorders in pear bymultivariate analysisrdquo Postharvest Biologyand Technology vol 31 no 1 pp 29ndash39 2004
Journal of Food Quality 11
[20] S Naima M R Khan and S Maria ldquoAntioxidant activitytotal phenolic and total flavonoid contents of whole plantextracts Torilis leptophylla Lrdquo BMC Complementary and Al-ternative Medicine vol 12 no 1 p 221 2012
[21] Y Nakano and K Asada ldquoPurification of ascorbate peroxi-dase in spinach chloroplasts its inactivation in ascorbate-depleted medium and reactivation by monodehydroascorbateradicalrdquo Plant amp Cell Physiology vol 28 no 1 pp 131ndash1401987
[22] C H Foyer and B Halliwell ldquoe presence of glutathione andglutathione reductase in chloroplasts a proposed role inascorbic acid metabolismrdquo Planta vol 133 no 1 pp 21ndash251976
[23] F Zhu Z Yun Q Ma et al ldquoEffects of exogenous 24-epi-brassinolide treatment on postharvest quality and resistanceof Satsuma Mandarin (Citrus unshiu)rdquo Postharvest Biologyand Technology vol 100 pp 8ndash15 2015
[24] S Zhu and B Ma ldquoBenzothiadiazole- or methyl jasmonate-induced resistance toColletotrichum musaein harvested ba-nana fruit is related to elevated defense enzyme activitiesrdquolteJournal of Horticultural Science and Biotechnology vol 82no 4 pp 500ndash506 2007
[25] J-W Han J-P Qian C-J Zhao X-T Yang and B-L FanldquoMathematical modelling of cooling efficiency of ventilatedpackaging integral performance evaluationrdquo InternationalJournal of Heat andMass Transfer vol 111 pp 386ndash397 2017
[26] X Zheng L Ye T Jiang G Jing and J Li ldquoLimiting thedeterioration of mango fruit during storage at room tem-perature by oxalate treatmentrdquo Food Chemistry vol 130no 2 pp 279ndash285 2012
[27] J K Dhemre D P Waskar S D Masalkar andR S Gaikwad ldquoEffect of post-harvest treatments on shelf lifeand quality of mango cv Kesar in cool storage and ambientconditionsrdquo Agricultural Science Digest vol 25 no 2pp 79ndash84 2005
[28] M Fleancu ldquoCorrelations among some physiological pro-cesses in apple fruit during growing and maturation pro-cessesrdquo International Journal of Agriculture amp Biologyvol 8530 pp 9ndash4 2007
[29] H Vergara-Domınguez J J Rıos B Gandul-Rojas andM Roca ldquoChlorophyll catabolism in olive fruits (var Arbe-quina and Hojiblanca) during maturationrdquo Food Chemistryvol 212 pp 604ndash611 2016
[30] S S Zaharah and Z Singh ldquoPostharvest nitric oxide fumi-gation alleviates chilling injury delays fruit ripening andmaintains quality in cold-stored ldquoKensington Priderdquo mangordquoPostharvest Biology and Technology vol 60 no 3 pp 202ndash210 2011
[31] M Babalar M Asghari A Talaei and A Khosroshahi ldquoEffectof pre- and postharvest salicylic acid treatment on ethyleneproduction fungal decay and overall quality of Selva strawberryfruitrdquo Food Chemistry vol 105 no 2 pp 449ndash453 2007
[32] A Ali M K Ong and C F Forney ldquoEffect of ozone pre-conditioning on quality and antioxidant capacity of papayafruit during ambient storagerdquo Food Chemistry vol 142 no 2pp 19ndash26 2014
[33] X Wang S Gu and B Chen ldquoe mechanism of cholesterol-effect on the quality of green asparagus (Asparagus officinalisL) spears during low temperature storagerdquo Scientia Horti-culturae vol 231 pp 36ndash42 2018
[34] M Sivapriya and S Leela ldquoIsolation and purification of anovel antioxidant protein from the water extract of Sundakai(Solanum torvum) seedsrdquo Food Chemistry vol 104 no 2pp 510ndash517 2007
[35] F V Breusegem E Vranova J F Dat and D Inze ldquoe roleof active oxygen species in plant signal transductionrdquo PlantScience vol 161 no 3 pp 405ndash414 2001
[36] L M Segal and R A Wilson ldquoReactive oxygen speciesmetabolism and plant-fungal interactionsrdquo Fungal Geneticsand Biology vol 110 pp 1ndash9 2018
[37] Y Wang X Xie and L E Long ldquoe effect of postharvestcalcium application in hydro-cooling water on tissue calciumcontent biochemical changes and quality attributes of sweetcherry fruitrdquo Food Chemistry vol 160 no 11 pp 22ndash30 2014
[38] Y Imahori J Bai and E Baldwin ldquoAntioxidative responses ofripe tomato fruit to postharvest chilling and heating treat-mentsrdquo Scientia Horticulturae vol 198 no 75 pp 398ndash4062016
supernatant was measured at 325 nm e content of theflavonoids was expressed as OD325g at 325 nm by using aspectrophotometer (PerkinElmer Lambda 35 UK)
For all the internal quality evaluations three replicateswere performed for each treatment and ten fruits were usedfor each replicate
226 Decay Evaluation e decay rate of fruit was visuallyevaluated Fruits with visible disease development wereconsidered decayed and the percentage of decay fruits wasused for expressing decay rate
decay rate total number of decayed fruits
total number of fruitstimes 100 (2)
e decay index of fruit was visually evaluated andscored on from 0 to 4 ere were three replicates in eachtreatment and each replicate contained thirty fruits
23 Reactive Oxygen Species and Related Enzymes
231 O2minus Production Rate According to Liu et al [15] fruitflesh (20 g) was added with 4ml of 100mM phosphatebuffer (pH 78 containing 2 PVPP and precooled at 4degC)and grinded on ice After centrifugation at 10000times g at 4degCfor 20min the supernatant was collected for the mea-surement of O2minus production rate e KNO2 solution wasused to make the standard curve e O2minus production ratewas expressed as nmolmiddotgminus1middotFWmiddotminminus1
232 Malondialdehyde Content According to Hodges et al[16] 10 g fruit flesh was added with 10 (wv) TCA solutionthat was precooled at 4degC After grinding and centrifugationat 10000times g at 4degC for 20min the supernatant was used forMDA measurement by using a spectrophotometer (Perki-nElmer Lambda 35 UK) e MDA content was calculatedusing the following formula
CMDAμmolL
1113888 1113889 645 times OD532 minusOD600( 1113857minus 056 times OD450
(3)
233 Glutathione Content According to Brehe and Burch[17] fruit flesh (10 g) was homogenized on ice with 3ml of5 (wv) TCA solution that contained 5mMEDTA-Na2 andwas precooled at 4degC After centrifugation at 10000times g at4degC for 20min the supernatant was collected for GSHmeasurement GSH content was expressed as nmolmiddotgminus1middotFW
234 Superoxide Catalase Ascorbic Peroxidase and Glu-tathione Reductase Activities Superoxide catalase ascorbicperoxidase and glutathione reductase activities wereexpressed as 001 changes in absorbance at correspondingnm per minute per g flesh tissue by using a spectropho-tometer (PerkinElmer Lambda 35 UK)
Superoxide (SOD) activity was determined according toProchazkova et al [18] and Larrigaudiere et al [19] e
amount of enzyme that inhibited 50 of NBTphotochemicalreduction was defined as a SOD activity unit
Catalase (CAT) activity was determined according toNaima et al [20] and expressed as 001 change in absorbanceat 240 nm per minute per g flesh tissue
Ascorbic peroxidase (APX) activity was determinedaccording to Nakano and Asada [21] and expressed as 001changes in absorbance at 290 nm per minute per g fleshtissue
Glutathione reductase (GR) activity was determinedaccording to Foyer and Halliwell [22] and expressed as 001changes in absorbance at 340 nm per minute per g of fleshtissue
235 Peroxidase and Polyphenoloxidase ActivityPeroxidase (POD) activity was determined according to Zhuet al [23] 500 μL of 05 (vv) guaiacol and 15mL of 50mMacetate buffer (pH 55) were added into 500 μL enzymeextraction e reaction started when 500 μL of0059MH2O2 was added e enzyme activity unit wasdetermined by monitoring the increase of absorbance at470 nm per min e enzyme activity was expressed asUmiddotgminus1middotFWminus1 Polyphenoloxidase (PPO) activity was de-termined according to Zhu and Ma [24] One PPO activityunit was defined as 1 change in absorbance at 420 nm perminute per g of flesh tissue by using a spectrophotometer(PerkinElmer Lambda 35 UK)
24 Statistical Analysis SPSS 110 for Windows (SPSS IncChicago IL) was used for data collection and analysis with aone-way analysis of variance (ANOVA) Duncanrsquos multiplecomparison was used to separate means at the 5 level
3 Results
31 Effects of Forced Air Precooling on External Quality ofMango Fruits during Storage
311 Firmness Mango fruits firmness decreased dramati-cally after harvest while precooling treatment retarded thedecrease e precooled fruit had higher firmness than thecontrol group during the whole period On the 10th day and15th day precooled fruits had 333 and 624 higherfirmness than control fruits respectively (Figure 1(a))
312 Weight Loss As shown in Figure 1(b) weight loss ofmango fruits increased steadily and precooling treatmentincreased fruit weight loss slightly On the 20th day ofstorage precooled fruits had 22 higher weight loss thancontrol fruits
313 Color As shown in Figure 2(a) the yellow index inmango fruits was increased steadily during storage whileprecooling treatment inhibited the color change On the 10thday and 15th day the precooled fruits had 233 and 145 alower yellow index than control fruits respectively e
Journal of Food Quality 3
0
1
2
3
4
0 5 10 15 20
Firm
ness
(N)
Days of storage
ControlPrecooling
(a)
0
2
4
6
8
5 10 15 20
Wei
ght l
oss (
)
Days of storage
ControlPrecooling
(b)
Figure 1 Eects of forced air precooling treatment on rmness (a) and weight loss (b)
Days of storage
0
20
40
60
80
100
10 15 20
Yello
w in
cide
nce (
)
ControlTreatment
(a)
40
50
60
70
80
0 5 10 15 20
Llowast
ControlPrecooling
Days of storage
(b)
ndash30
ndash20
ndash10
0
10
20
0 5 10 15 20
alowast
Days of storage
ControlPrecooling
(c)
30
40
50
60
70
0 5 10 15 20
blowast
Days of storage
ControlPrecooling
(d)
FIGURE 2 Eects of forced air precooling treatment on the (a) yellow index (b) Llowast value (c) alowast value and (d) blowast value
4 Journal of Food Quality
difference between precooled and control fruit was notsignificant at the end of storage
Llowast value from low to high indicates that the lightnessincreases Llowast value of mango fruits peel increased with theprolonging of the storage time Llowast value in precooled fruitswas lower than control fruits during the entire storageperiod On the 10th day the Llowast value of precooled fruits was115 lower than that of control fruits (Figure 2(b)) alowast valuefrom negative to positive represents that the color changesfrom green to red and blowast was from blue to yellow With theextension of storage alowast and blowast values of mango fruits peelwere all increased steadily which showed that the peel colorwas changing from green to yellow Precooling treatmentretarded the increase of alowast and blowast during the beginning ofthe storage On the 10th day precooled fruits had 478lower alowast and 149 lower blowast than that of control fruitsrespectively (Plt 005) e differences between precooledand control fruits were not significant at the end of storage(Figures 2(c) and 2(d))
314 Pigment Content Figure 3 showed pigment changes inmango fruit flesh and peel With the ripening of mangofruits chlorophyll a in mango fruits peel decreased dra-matically and the decrease of control fruits was higher thanprecooled fruits On the 20th day of storage precooled fruitspeel had 84 higher chlorophyll a than control fruits(Figure 3(a)) Chlorophyll a in mango fruits flesh was alsodecreased dramatically On the 10th day precooled fruitsfresh had a significantly higher level of chlorophyll a thanthat of control fruits At other times there was no significantdifference (Figure 3(b))
e change tendency of chlorophyll b in mango fruitspeel was similar to chlorophyll a and precooling treatmentalso retarded chlorophyll b reduction On the 15th and 20thday of storage precooled fruits peel had 188 and 200higher chlorophyll b than that of control fruits re-spectively (Figure 3(c)) However there was no significantdifference in chlorophyll b between precooled fruitsflesh and control fruits flesh during the storage period(Figure 3(d))
32 Effects of Forced Air Precooling on Internal Quality ofMango Fruits during Storage
321 Total Soluble Solids As shown in Figure 4(a) TSS ofcontrol fruits increased during the first 15 days and thendecreased Precooling treatment retarded the increase ofTSS and there was no decrease until the end of storageerefore on the 20th day of storage the TSS in precooledfruits was 116 higher than the control
322 Titratable Acidity Figure 4(b) showed the changes ofTA content in mango fruits during storage TA in mangofruits changed slightly during first 10 days after which TAdecreased rapidly Precooled fruits exhibited less decreasecompared to the control On the 15th day precooled fruitshad 395 higher TA content than control fruits
323 Soluble Sugar Content Soluble sugar content ofmango fruits in both precooled fruits and control fruitsincreased steadily with the increase of storage time At thebeginning of storage soluble sugar content in precooledfruits was slightly lower than that of control fruits At the endof the storage however soluble sugar content in precooledfruits was slightly higher than that of controls fruit But therewas no significant difference between the two groups(Figure 4(c))
324 Starch Content Figure 4(d) showed that starchcontent decreased continuously during the whole storageperiod On the 20th day starch content was only 25 of theinitial value Precooling treatment delayed the decrease ofstarch content during the beginning of the storage periodOn the 5th 10th and 15th precooled fruits had 273 223and 377 higher starch content than the control grouprespectively
325 Flavonoid Content As shown in Figure 5 flavonoidscontent was decreased in both precooled and control fruitsand then increased slightly at the first 5 days Flavonoid inprecooled fruits increased more rapidly than that in thecontrol On the 10th 15th and 20th day precooled fruits had103 112 and 61 higher flavonoids content thancontrol respectively
33 Effects of Forced Air Precooling Treatment on Decay In-cidence and Decay Severity of Mango Fruits during StorageDecay incidence and decay severity of mango fruits that werestored at 13degC and 85sim95 RH was shown in Figures 6(a)and 6(b) Precooling treatment decreased fruit decay in bothdecay incidence and decay index On the 20th day precooledfruits had 397 lower decay rate and 413 lower decayindex than control fruits respectively
34 Effects of Forced Air Precooling Treatment on ReactiveOxygen Species and Related Enzymes of MangoFruits during Storage
341 O2minus Production ere was no significant change ofO2minus production rate in mango fruits during the beginning ofstorage After 10 days rate of O2minus production in controlfruits increased rapidly and suddenly while that in pre-cooled fruits increased slightly On the 15th and 20th day rateof O2minus production in precooled fruits was only 678 and645 of control fruits respectively (Figure 7(a))
342 Malondialdehyde Content Figure 7(b) showed thatMDA content in control fruits increased rapidly at the first5 days of storage and then kept steady while MDA contentin precooled fruits increased steadily during the wholestorage On the 5th and 10th day MDA content in precooledfruits was only 661 and 802 of that in control fruits Inthe storage period MDA content of precooled fruits wasgradually close to the control At the end of the storage
Journal of Food Quality 5
period there was no signicant dierence between theMDAcontent of two groups
343 Superoxide Catalase Peroxidase and Ascorbic Per-oxidase Activities As shown in Figure 8 during the wholestorage period the activities of SOD CAT POD and APXin mango fruits showed a constant increase tendencyPrecooled fruits exhibited higher SOD and CAT activitiesin the entire storage period On the 20th day treated fruitshad 232 higher CAT activity and 27 higher SOD ac-tivity than control fruits respectively (Figures 8(a) and8(b))
Precooling treatment enhanced POD activity in mangofruits except on the 5th day of storage On the 15th and 20thday of storage precooled fruits had 236 and 105 higherPOD activity than control fruits respectively (Figure 8(c))At the beginning of storage precooled fruits showed higherAPX activity which was 1266 higher than the controlWhile at the end of storage precooling treatment had no
signicant incopyuence on APX activity in mango fruits(Figure 8(d))
344 Glutathione Content and Glutathione ReductaseActivity As shown in Figure 9(a) GSH content in mangofruits showed a gradually increase during rst 10 days andthen decreased slowly Precooled fruits had higher GSHcontent than control fruits during the whole storage On the10th and 15th day of storage treated fruits had 221 and127 higher GSH content than control fruits respectively
GR activity in mango fruits increased with the pro-longing of the storage time Precooled fruits had lower GRactivity than control fruits at earlier storage At the end of thestorage the GR activity in precooled fruits was slightlyhigher but the dierence was not signicant (Pgt 005Figure 9(b))
345 Polyphenoloxidase Activity As shown in Figure 10PPO activity in control fruits increased dramatically at
0
2
4
6
8
0 5 10 15 20
Chlo
roph
yll a
cont
ent
(mgmiddot
100g
ndash1middotF
W)
ControlPrecooling
Days of storage
(a)
Chlo
roph
yll a
cont
ent
(mgmiddot
100g
ndash1middotF
W)
ControlPrecooling
00
02
04
06
0 5 10 15 20Days of storage
(b)
Chlo
roph
yll b
cont
ent
(mgmiddot
100g
ndash1middotF
W)
ControlPrecooling
00
05
10
15
20
25
0 5 10 15 20Days of storage
(c)
Chlo
roph
yll b
cont
ent
(mgmiddot
100g
ndash1middotF
W)
ControlPrecooling
00
01
02
0 5 10 15 20Days of storage
(d)
Figure 3 Eects of forced air precooling treatment on chlorophyll a of peel (a) and copyesh (b) and chlorophyll b of mango fruit peel (c) and copyesh(d)
6 Journal of Food Quality
earlier storage and had a peak activity on the 5th day ofstorage after which PPO activity decreased and was keptstable PPO activity in precooled fruits was always at a lowerlevel On the 5th day and 20th day precooled fruits had 819and 674 lower PPO activity than control fruitsrespectively
4 Discussion
Mango fruits are a typical climacteric fruit and commonlyharvested at a green mature stage to prevent the postharvestloss [25] After harvest fruits begin to ripe with the char-acteristic changes on peel coloration textural softeningsugar maintenance suer from over softening and ripeningduring storage which result in postharvest quality de-terioration and short shelf-life [26] In this study the resultsshowed that precooling treatment could retard fruit soft-ening peel coloration accumulation of sugar and organicacid and disease development on mango fruits and all ofwhich were closely related to the maintenance of fruitripening [27]
04
05
06
07
08
09
10
0 5 10 15 20
Flav
onoi
ds co
nten
t (O
D32
5 gndash1
middotFW
)
Days of storage
ControlPrecooling
Figure 5 Eects of forced air precooling treatment on copyavonoidcontent
4
8
12
16
20
0 5 10 15 20
Tota
l sol
uble
solid
s (
)
ControlPrecooling
Days of storage
(a)
0
1
2
0 5 10 15 20
Titr
atab
le ac
idity
cont
ent (
)
ControlPrecooling
Days of storage
(b)
ControlPrecooling
02
03
04
05
06
0 5 10 15 20
Solu
ble s
ugar
cont
ent (
)
Days of storage
(c)
ControlPrecooling
00
02
04
06
08
0 5 10 15 20
Star
ch co
nten
t (
)
Days of storage
(d)
FIGURE 4 Eects of forced air precooling treatment on TSS (a) TA (b) soluble sugar (c) and starch (d) content
Journal of Food Quality 7
Firmness is an important parameter in postharveststorage and marketing Loss of rmness caused by degra-dation of cell wall and starch may result in physical damagesin transportation and fruit susceptibility to pathogen attacks[2] In this study precooled fruits showed higher rmnessduring the entire storage It is in coincidence with previousstudy on waxberry and black mulberry fruits [1] It indicatedthat precooling treatment could retard mango fruitrsquos soft-ening and ripening and it might be related to the decreasedrespiration in the early of storage During postharvest rip-ening the chlorophyll content in mango peel decreased andthe peel color changes from green to yellow [28] Usually thepeel color was considered as an important indicator of fruitmaturity and a critical parameter in fruit marketing [29] Inthis study precooled fruits showed a lower yellow index andblowast value than control fruits and it was closely related to
higher chlorophyll a and chlorophyll b content in mangofruits peel during the storage [13] However the pigment inmango copyesh was not incopyuenced by precooling treatmentFruit weight loss is an important postharvest parameterincopyuencing fruit storage quality shelf-life and economicvalue In the current study however precooling treatmentpromoted fruit weight loss in storage at might be becausethat precooling treatment speeded water transpiration onmango fruitrsquos surface and enhanced fruit water loss Forcedair precooling was done without humidied air leading tohigher weight loss
After harvest mango fruits showed high respiration rateand metabolism activity which accelerated the consumptionof nutritional compounds and fruit ripening With fruitripening SSC and soluble sugar increase because of poly-saccharide hydrolysis while starch a vital polysaccharide in
0
2
4
6
8
10
0 5 10 15 20Days of storage
ControlTreatment
Rate
of O
2ndash pro
duct
ion
(nm
olmiddotg
ndash1middotF
Wmiddotm
inndash1
)
(a)
ControlTreatment
005
010
015
0 5 10 15 20
MD
A co
nten
t (nm
olmiddotg
ndash1middotF
W )
Days of storage
(b)
Figure 7 Eects of forced air precooling treatment on Ominus2 production (a) and MDA content (b)
0
20
40
60
80
100
10 15 20
Dec
ay in
cide
nce (
)
Days of storage
ControlPrecooling
(a)
ControlPrecooling
0
1
2
3
4
10 15 20
Dec
ay se
verit
y (
)
Days of storage
(b)
Figure 6 Eects of forced air precooling treatment on decay incidence (a) and decay severity (b)
8 Journal of Food Quality
fruit decreases continuously [30] In the current studyprecooled fruits showed lower SSC and higher starch contentduring the entire storage It indicated precooling treatmentretarded the hydrolysis of polysaccharides to SSC Mean-while starch degradation is closely related with fruit soft-ening Inhibiting the degradation of starch to SSC alsocontributed to the fruit rmness maintenance [15] econtent of TA represents the concentration of organic acidin fruits Fruit respiration can promote organic acid con-sumption and reduce TA content [31] During storage thecontent of TA in mango fruits decreased rapidly and pre-cooling treatment inhibited the tendency e change ofSSC TA and starch content might be related to the delay inthe ripening process and reduction of respiration rate Incoincidence with the previous study on apricot [10] pre-cooling treatment enhanced copyavonoids content in mangofruits in the late stage of storage Flavonoids content is animportant indicator of fruitrsquos antioxidant capacity [32] and
precooling treatment might contribute to mango fruitsantioxidant capacities However possible mechanisms needto be studied further
With the prolonging of storage fruit resistance topathogen decreases because of ripening and softening anddecay happens e current study found that precoolingtreatment reduced decay on mango fruits including decayincidence and decay index (decay severity) which is similarto the study on green asparagus and broccoli [33] It ispossible because that precooling treatment retarded mangofruit ripening and maintained fruit resistance to postharvestpathogens
Although reactive oxygen species (ROS) was benecial tothe improvement of plant disease resistance excessive ROScan aect DNA replication and protein synthesis resultingin fruit senescence [34] According to free radical theorysenescence was a process of active oxygen metabolismdisorders and accumulation When the fruits are forced by
0
10
20
30
40
0 5 10 15 20
CAT
activ
ity (U
middotgndash1
middotFW
middotmin
ndash1)
ControlTreatment
Days of storage
(a)
ControlTreatment
Days of storage
50
55
60
0 5 10 15 20
SOD
activ
ity (U
middotgndash1
middotFW
)
(b)
ControlTreatment
0
200
400
600
0 5 10 15 20
POD
activ
ity (U
middotgndash1
middotFW
middotmin
ndash1)
Days of storage
(c)
ControlTreatment
0
100
200
300
400
500
0 5 10 15 20
APX
activ
ity (U
middotgndash1
middotFW
middotmin
ndash1)
Days of storage
(d)
Figure 8 Eects of forced air precooling treatment on CAT (a) SOD (b) POD (c) and APX (d) activity
Journal of Food Quality 9
outside stresses reactive oxygen species metabolism balanceis broken free radicals are accumulated in abundance andthe peroxidation of membrane lipid is improved or aggra-vated all of which induce the fruit senescence [13] O2minus is akind of reactive oxygen species with relatively high viru-lence playing an important role in horticultural plant rip-ening and senescence processes particularly in membranedeterioration [35] is study showed that the O2minus pro-duction rate in mango fruits increased rapidly at the end ofstorage leading to senescence of mango Precooling treat-ment inhibited the increase of O2minus production rate andsubsequent fruit senescence Moreover being as the productof membrane lipid peroxidation MDA was usually used toevaluate the degree of membrane damage [36] and lipidperoxidation [37] In this study MDA content was increasedrapidly during the later storage period and was always at ahigher levelis veried that the mango fruitrsquos cellulose was
peroxidated and the integrity of the cell membrane wasdestroyed
ere are many active oxygen removal systems in planttissue e excessive active oxygen was eliminated by dif-ferent antioxidant enzymes [13] O2minus can be transformedinto H2O2 by SOD in the plants is study found thatprecooling treatment enhanced the SOD activity of mangofruits during storage at might be why precooled fruit hadlower O2minus production rate than control fruits In additionwe also found that precooled fruits had higher CAT andPOD activities than control fruits We could include thatprecooled fruits had lower reactive oxygen species thancontrol fruits However there was no signicant dierenceof APX between the precooled fruits and control fruits in thisstudy is could be due to the higher activity of CAT andPOD in mango fruits and APX had not played a major partin elimination of H2O2 erefore the balance betweenSOD POD CAT and APX activities in plants is importantfor determining the steady-state levels of H2O2 and ROS[38]
Glutathione (GSH) is also a very important kind of theactive oxygen removal material [35] In plant tissue GSHcan reduce dehydroascorbic acid (DHA) to ascorbic acid(ASA) and ASA can eliminate H2O2 directly Glutathionereductase (GR) is the key enzyme involved in the GSHgeneration from oxidized glutathione (GSSC) [13 35] isstudy showed that precooled fruits had a higher GSHcontent and GR activity than control fruits during thestorage all of which contributed to the delay of fruit ripeningand senescence
Previous reports indicated that PPO was directly relatedto browning and decay Decrease in its activity would lead toan induced resistance to browning and decay [25] In normalcircumstances PPO usually exists in organelles membraneand cell membrane so the PPO activity is low [13]When thestructure of cell membrane is destroyed PPO is released andthe activity increases In this study the PPO activity in
20
40
60
80
0 5 10 15 20
GSH
cont
ent (
nmol
middotgndash1
middotFW
)
Days of storage
ControlTreatment
(a)
ControlTreatment
0
100
200
300
0 5 10 15 20
GR
activ
ity (U
middotgndash1
middotFW
middotmin
ndash1)
Days of storage
(b)
Figure 9 Eects of forced air precooling treatment on GSH content (a) and GR activity (b)
0
2
4
6
8
10
12
14
0 5 10 15 20
PPO
activ
ity (U
middotgndash1
middotFW
middotmin
ndash1)
Days of storage
ControlTreatment
Figure 10 Eects of forced air precooling treatment on PPOactivity
10 Journal of Food Quality
precooled fruits was always kept in a low level and thismight be because the precooling treatment enhanced theantioxidant defense capabilities and helped to maintain cellintegrity
5 Conclusion
Mango fruitrsquos quality was significantly improved by forcedair precooling treatment Precooling treatment delayed fruitripening and senescence with inhibition of ROS and en-hancement of active oxygen removal enzymes such as su-peroxide dismutase (SOD) catalase (CAT) peroxidase(POD) glutathione reductase (GR) and polyphenoloxidase(PPO) e firmness was maintained and fruit decay wasinhibited during storage ese results indicate that forcedair precooling treatment could maintain mango fruitrsquosquality by enhancing antioxidant activity and delaying fruitripening erefore it is suggested that mango fruits shouldbe precooled immediately after harvest for maintaining fruitquality and prolonging shelf-life
Data Availability
e data used to support the findings of this study areavailable from the corresponding author upon request
Conflicts of Interest
e authors declare that there are no conflicts of interestassociated with the publication of this manuscript
Acknowledgments
is research was supported by Support Project of High-Level Teachers in Beijing Municipal Universities in thePeriod of the 13th Five-Year Plan (CITampTCD201704037)Construction of Scientific Research Innovation ServiceAbility-Basic Scientific Research Operating Expense-FoodFeature Project (PXM2018_014213_000033) and SupportProject of High-Level Teachers in Beijing Municipal Uni-versities (IDHT20180506)
References
[1] Q Han H Gao H Chen X Fang and W Wu ldquoPrecoolingand ozone treatments affects postharvest quality of blackmulberry (Morus nigra) fruitsrdquo Food Chemistry vol 221pp 1947ndash1953 2017
[2] G M Cosme Silva W B Silva D B Medeiros et al ldquoechitosan affects severely the carbon metabolism in mango(Mangifera indica L cv Palmer) fruit during storagerdquo FoodChemistry vol 237 pp 372ndash378 2017
[3] J Li Q Li X J Lei et al ldquoEffects of wax coating on themoisture loss of cucumbers at different storage temperaturesrdquoJournal of food quality vol 2018 no 12 pp 1ndash6 2018
[4] H J Zhou Z W YE M S Su and J H Du ldquoEffects of lowtemperature and forced air precooling on precooling per-formance of different varieties of peach fruitsrdquo Storage ampProcess vol 15 pp 16ndash19 2015
[5] A Rab H Rehman I Haq M Sajid K Nawab and K AlildquoHarvest stages and pre-cooling influence the quality and
storage life of tomato fruitrdquo Journal Animal amp Plant Sciencevol 23 no 5 pp 1347ndash1357 2013
[6] M Zhou K H Ndeurumio L Zhao and Z Hu ldquoImpact ofprecooling and controlled-atmosphere storage on γ--aminobutyric acid (GABA) accumulation in longan (dimo-carpus longan lour) fruitrdquo Journal of Agricultural and FoodChemistry vol 64 no 33 pp 6443ndash6450 2016
[7] D Martinez-Romero S Castillo and D Valero ldquoForced aircooling applied before fruit handling to prevent mechanicaldamage of plums (Prunus salicina Lindl)rdquo Postharvest Biologyamp Technology vol 28 no 1 pp 135ndash142 2003
[8] H Nalbandi S Seiiedlou H R Ghasemzadeh andF Rangbar ldquoInnovative parallel airflow system for forced-aircooling of strawberriesrdquo Food and Bioproducts Processingvol 100 pp 440ndash449 2016
[9] J L OrsquoSullivan M J Ferrua R Love P VerbovenB Nicolaı and A East ldquoForced air cooling of polylinedhorticultural produce optimal cooling conditions andpackage designrdquo Postharvest Biology amp Technology vol 126pp 67ndash75 2017
[10] J Yan Y Song J Li and W Jiang ldquoForced-air precoolingtreatment enhanced antioxidant capacities of apricotsrdquoJournal of Food Processing and Preservation vol 42 no 1article e13320 2018
[11] M Jincy M Djanaguiraman P JeyakumarK S Subramanian S Jayasankar and G Paliyath ldquoInhibitionof phospholipase D enzyme activity through hexanal leads todelayed mango (Mangifera indica L) fruit ripening throughchanges in oxidants and antioxidant enzymes activityrdquo Sci-entia Horticulturae vol 218 pp 316ndash325 2017
[12] J Li G W Ma L Ma et al ldquoMultivariate analysis of fruitantioxidant activities of blackberry treated with 1-Methyl-cyclopropene or vacuum precoolingrdquo International Journal ofAnalytical Chemistry vol 2018 Article ID 2416461 5 pages2018
[13] P Sharma A B Jha R S Dubey andM Pessarakli ldquoReactiveoxygen species oxidative damage and antioxidative defensemechanism in plants under stressful conditionsrdquo Journal ofBotany vol 2012 Article ID 217037 26 pages 2012
[14] O Elloumi M Ghrab andM BenMimoun ldquoEffects of flowerbuds removal on seasonal starch storage and mobilization infruiting and non-fruiting branches of pistachio trees cvMateur under dry and warm climaterdquo Scientia Horticulturaevol 172 no 3 pp 19ndash25 2014
[15] K Liu J Liu H Li C Yuan J Zhong and Y Chen ldquoInfluenceof postharvest citric acid and chitosan coating treatment onripening attributes and expression of cell wall related genes incherimoya (Annona cherimola Mill) fruitrdquo Scientia Horti-culturae vol 198 no 10 pp 1ndash11 2016
[16] D M Hodges J M Delong C F Forney and R K PrangeldquoImproving the thiobarbituric acid-reactive-substances assayfor estimating lipid peroxidation in plant tissues containinganthocyanin and other interfering compoundsrdquo Plantavol 207 no 4 pp 604ndash611 1999
[17] J E Brehe andH B Burch ldquoEnzymatic assay for glutathionerdquoAnalytical Biochemistry vol 74 no 1 pp 189ndash197 1976
[18] D Prochazkova R K Sairam G C Srivastava andD V Singh ldquoOxidative stress and antioxidant activity as thebasis of senescence in maize leavesrdquo Plant Science vol 161no 4 pp 765ndash771 2001
[19] C Larrigaudiere I Lentheric J Puy and E Pinto ldquoBio-chemical characterisation of core browning and brown heartdisorders in pear bymultivariate analysisrdquo Postharvest Biologyand Technology vol 31 no 1 pp 29ndash39 2004
Journal of Food Quality 11
[20] S Naima M R Khan and S Maria ldquoAntioxidant activitytotal phenolic and total flavonoid contents of whole plantextracts Torilis leptophylla Lrdquo BMC Complementary and Al-ternative Medicine vol 12 no 1 p 221 2012
[21] Y Nakano and K Asada ldquoPurification of ascorbate peroxi-dase in spinach chloroplasts its inactivation in ascorbate-depleted medium and reactivation by monodehydroascorbateradicalrdquo Plant amp Cell Physiology vol 28 no 1 pp 131ndash1401987
[22] C H Foyer and B Halliwell ldquoe presence of glutathione andglutathione reductase in chloroplasts a proposed role inascorbic acid metabolismrdquo Planta vol 133 no 1 pp 21ndash251976
[23] F Zhu Z Yun Q Ma et al ldquoEffects of exogenous 24-epi-brassinolide treatment on postharvest quality and resistanceof Satsuma Mandarin (Citrus unshiu)rdquo Postharvest Biologyand Technology vol 100 pp 8ndash15 2015
[24] S Zhu and B Ma ldquoBenzothiadiazole- or methyl jasmonate-induced resistance toColletotrichum musaein harvested ba-nana fruit is related to elevated defense enzyme activitiesrdquolteJournal of Horticultural Science and Biotechnology vol 82no 4 pp 500ndash506 2007
[25] J-W Han J-P Qian C-J Zhao X-T Yang and B-L FanldquoMathematical modelling of cooling efficiency of ventilatedpackaging integral performance evaluationrdquo InternationalJournal of Heat andMass Transfer vol 111 pp 386ndash397 2017
[26] X Zheng L Ye T Jiang G Jing and J Li ldquoLimiting thedeterioration of mango fruit during storage at room tem-perature by oxalate treatmentrdquo Food Chemistry vol 130no 2 pp 279ndash285 2012
[27] J K Dhemre D P Waskar S D Masalkar andR S Gaikwad ldquoEffect of post-harvest treatments on shelf lifeand quality of mango cv Kesar in cool storage and ambientconditionsrdquo Agricultural Science Digest vol 25 no 2pp 79ndash84 2005
[28] M Fleancu ldquoCorrelations among some physiological pro-cesses in apple fruit during growing and maturation pro-cessesrdquo International Journal of Agriculture amp Biologyvol 8530 pp 9ndash4 2007
[29] H Vergara-Domınguez J J Rıos B Gandul-Rojas andM Roca ldquoChlorophyll catabolism in olive fruits (var Arbe-quina and Hojiblanca) during maturationrdquo Food Chemistryvol 212 pp 604ndash611 2016
[30] S S Zaharah and Z Singh ldquoPostharvest nitric oxide fumi-gation alleviates chilling injury delays fruit ripening andmaintains quality in cold-stored ldquoKensington Priderdquo mangordquoPostharvest Biology and Technology vol 60 no 3 pp 202ndash210 2011
[31] M Babalar M Asghari A Talaei and A Khosroshahi ldquoEffectof pre- and postharvest salicylic acid treatment on ethyleneproduction fungal decay and overall quality of Selva strawberryfruitrdquo Food Chemistry vol 105 no 2 pp 449ndash453 2007
[32] A Ali M K Ong and C F Forney ldquoEffect of ozone pre-conditioning on quality and antioxidant capacity of papayafruit during ambient storagerdquo Food Chemistry vol 142 no 2pp 19ndash26 2014
[33] X Wang S Gu and B Chen ldquoe mechanism of cholesterol-effect on the quality of green asparagus (Asparagus officinalisL) spears during low temperature storagerdquo Scientia Horti-culturae vol 231 pp 36ndash42 2018
[34] M Sivapriya and S Leela ldquoIsolation and purification of anovel antioxidant protein from the water extract of Sundakai(Solanum torvum) seedsrdquo Food Chemistry vol 104 no 2pp 510ndash517 2007
[35] F V Breusegem E Vranova J F Dat and D Inze ldquoe roleof active oxygen species in plant signal transductionrdquo PlantScience vol 161 no 3 pp 405ndash414 2001
[36] L M Segal and R A Wilson ldquoReactive oxygen speciesmetabolism and plant-fungal interactionsrdquo Fungal Geneticsand Biology vol 110 pp 1ndash9 2018
[37] Y Wang X Xie and L E Long ldquoe effect of postharvestcalcium application in hydro-cooling water on tissue calciumcontent biochemical changes and quality attributes of sweetcherry fruitrdquo Food Chemistry vol 160 no 11 pp 22ndash30 2014
[38] Y Imahori J Bai and E Baldwin ldquoAntioxidative responses ofripe tomato fruit to postharvest chilling and heating treat-mentsrdquo Scientia Horticulturae vol 198 no 75 pp 398ndash4062016
Figure 1 Eects of forced air precooling treatment on rmness (a) and weight loss (b)
Days of storage
0
20
40
60
80
100
10 15 20
Yello
w in
cide
nce (
)
ControlTreatment
(a)
40
50
60
70
80
0 5 10 15 20
Llowast
ControlPrecooling
Days of storage
(b)
ndash30
ndash20
ndash10
0
10
20
0 5 10 15 20
alowast
Days of storage
ControlPrecooling
(c)
30
40
50
60
70
0 5 10 15 20
blowast
Days of storage
ControlPrecooling
(d)
FIGURE 2 Eects of forced air precooling treatment on the (a) yellow index (b) Llowast value (c) alowast value and (d) blowast value
4 Journal of Food Quality
difference between precooled and control fruit was notsignificant at the end of storage
Llowast value from low to high indicates that the lightnessincreases Llowast value of mango fruits peel increased with theprolonging of the storage time Llowast value in precooled fruitswas lower than control fruits during the entire storageperiod On the 10th day the Llowast value of precooled fruits was115 lower than that of control fruits (Figure 2(b)) alowast valuefrom negative to positive represents that the color changesfrom green to red and blowast was from blue to yellow With theextension of storage alowast and blowast values of mango fruits peelwere all increased steadily which showed that the peel colorwas changing from green to yellow Precooling treatmentretarded the increase of alowast and blowast during the beginning ofthe storage On the 10th day precooled fruits had 478lower alowast and 149 lower blowast than that of control fruitsrespectively (Plt 005) e differences between precooledand control fruits were not significant at the end of storage(Figures 2(c) and 2(d))
314 Pigment Content Figure 3 showed pigment changes inmango fruit flesh and peel With the ripening of mangofruits chlorophyll a in mango fruits peel decreased dra-matically and the decrease of control fruits was higher thanprecooled fruits On the 20th day of storage precooled fruitspeel had 84 higher chlorophyll a than control fruits(Figure 3(a)) Chlorophyll a in mango fruits flesh was alsodecreased dramatically On the 10th day precooled fruitsfresh had a significantly higher level of chlorophyll a thanthat of control fruits At other times there was no significantdifference (Figure 3(b))
e change tendency of chlorophyll b in mango fruitspeel was similar to chlorophyll a and precooling treatmentalso retarded chlorophyll b reduction On the 15th and 20thday of storage precooled fruits peel had 188 and 200higher chlorophyll b than that of control fruits re-spectively (Figure 3(c)) However there was no significantdifference in chlorophyll b between precooled fruitsflesh and control fruits flesh during the storage period(Figure 3(d))
32 Effects of Forced Air Precooling on Internal Quality ofMango Fruits during Storage
321 Total Soluble Solids As shown in Figure 4(a) TSS ofcontrol fruits increased during the first 15 days and thendecreased Precooling treatment retarded the increase ofTSS and there was no decrease until the end of storageerefore on the 20th day of storage the TSS in precooledfruits was 116 higher than the control
322 Titratable Acidity Figure 4(b) showed the changes ofTA content in mango fruits during storage TA in mangofruits changed slightly during first 10 days after which TAdecreased rapidly Precooled fruits exhibited less decreasecompared to the control On the 15th day precooled fruitshad 395 higher TA content than control fruits
323 Soluble Sugar Content Soluble sugar content ofmango fruits in both precooled fruits and control fruitsincreased steadily with the increase of storage time At thebeginning of storage soluble sugar content in precooledfruits was slightly lower than that of control fruits At the endof the storage however soluble sugar content in precooledfruits was slightly higher than that of controls fruit But therewas no significant difference between the two groups(Figure 4(c))
324 Starch Content Figure 4(d) showed that starchcontent decreased continuously during the whole storageperiod On the 20th day starch content was only 25 of theinitial value Precooling treatment delayed the decrease ofstarch content during the beginning of the storage periodOn the 5th 10th and 15th precooled fruits had 273 223and 377 higher starch content than the control grouprespectively
325 Flavonoid Content As shown in Figure 5 flavonoidscontent was decreased in both precooled and control fruitsand then increased slightly at the first 5 days Flavonoid inprecooled fruits increased more rapidly than that in thecontrol On the 10th 15th and 20th day precooled fruits had103 112 and 61 higher flavonoids content thancontrol respectively
33 Effects of Forced Air Precooling Treatment on Decay In-cidence and Decay Severity of Mango Fruits during StorageDecay incidence and decay severity of mango fruits that werestored at 13degC and 85sim95 RH was shown in Figures 6(a)and 6(b) Precooling treatment decreased fruit decay in bothdecay incidence and decay index On the 20th day precooledfruits had 397 lower decay rate and 413 lower decayindex than control fruits respectively
34 Effects of Forced Air Precooling Treatment on ReactiveOxygen Species and Related Enzymes of MangoFruits during Storage
341 O2minus Production ere was no significant change ofO2minus production rate in mango fruits during the beginning ofstorage After 10 days rate of O2minus production in controlfruits increased rapidly and suddenly while that in pre-cooled fruits increased slightly On the 15th and 20th day rateof O2minus production in precooled fruits was only 678 and645 of control fruits respectively (Figure 7(a))
342 Malondialdehyde Content Figure 7(b) showed thatMDA content in control fruits increased rapidly at the first5 days of storage and then kept steady while MDA contentin precooled fruits increased steadily during the wholestorage On the 5th and 10th day MDA content in precooledfruits was only 661 and 802 of that in control fruits Inthe storage period MDA content of precooled fruits wasgradually close to the control At the end of the storage
Journal of Food Quality 5
period there was no signicant dierence between theMDAcontent of two groups
343 Superoxide Catalase Peroxidase and Ascorbic Per-oxidase Activities As shown in Figure 8 during the wholestorage period the activities of SOD CAT POD and APXin mango fruits showed a constant increase tendencyPrecooled fruits exhibited higher SOD and CAT activitiesin the entire storage period On the 20th day treated fruitshad 232 higher CAT activity and 27 higher SOD ac-tivity than control fruits respectively (Figures 8(a) and8(b))
Precooling treatment enhanced POD activity in mangofruits except on the 5th day of storage On the 15th and 20thday of storage precooled fruits had 236 and 105 higherPOD activity than control fruits respectively (Figure 8(c))At the beginning of storage precooled fruits showed higherAPX activity which was 1266 higher than the controlWhile at the end of storage precooling treatment had no
signicant incopyuence on APX activity in mango fruits(Figure 8(d))
344 Glutathione Content and Glutathione ReductaseActivity As shown in Figure 9(a) GSH content in mangofruits showed a gradually increase during rst 10 days andthen decreased slowly Precooled fruits had higher GSHcontent than control fruits during the whole storage On the10th and 15th day of storage treated fruits had 221 and127 higher GSH content than control fruits respectively
GR activity in mango fruits increased with the pro-longing of the storage time Precooled fruits had lower GRactivity than control fruits at earlier storage At the end of thestorage the GR activity in precooled fruits was slightlyhigher but the dierence was not signicant (Pgt 005Figure 9(b))
345 Polyphenoloxidase Activity As shown in Figure 10PPO activity in control fruits increased dramatically at
0
2
4
6
8
0 5 10 15 20
Chlo
roph
yll a
cont
ent
(mgmiddot
100g
ndash1middotF
W)
ControlPrecooling
Days of storage
(a)
Chlo
roph
yll a
cont
ent
(mgmiddot
100g
ndash1middotF
W)
ControlPrecooling
00
02
04
06
0 5 10 15 20Days of storage
(b)
Chlo
roph
yll b
cont
ent
(mgmiddot
100g
ndash1middotF
W)
ControlPrecooling
00
05
10
15
20
25
0 5 10 15 20Days of storage
(c)
Chlo
roph
yll b
cont
ent
(mgmiddot
100g
ndash1middotF
W)
ControlPrecooling
00
01
02
0 5 10 15 20Days of storage
(d)
Figure 3 Eects of forced air precooling treatment on chlorophyll a of peel (a) and copyesh (b) and chlorophyll b of mango fruit peel (c) and copyesh(d)
6 Journal of Food Quality
earlier storage and had a peak activity on the 5th day ofstorage after which PPO activity decreased and was keptstable PPO activity in precooled fruits was always at a lowerlevel On the 5th day and 20th day precooled fruits had 819and 674 lower PPO activity than control fruitsrespectively
4 Discussion
Mango fruits are a typical climacteric fruit and commonlyharvested at a green mature stage to prevent the postharvestloss [25] After harvest fruits begin to ripe with the char-acteristic changes on peel coloration textural softeningsugar maintenance suer from over softening and ripeningduring storage which result in postharvest quality de-terioration and short shelf-life [26] In this study the resultsshowed that precooling treatment could retard fruit soft-ening peel coloration accumulation of sugar and organicacid and disease development on mango fruits and all ofwhich were closely related to the maintenance of fruitripening [27]
04
05
06
07
08
09
10
0 5 10 15 20
Flav
onoi
ds co
nten
t (O
D32
5 gndash1
middotFW
)
Days of storage
ControlPrecooling
Figure 5 Eects of forced air precooling treatment on copyavonoidcontent
4
8
12
16
20
0 5 10 15 20
Tota
l sol
uble
solid
s (
)
ControlPrecooling
Days of storage
(a)
0
1
2
0 5 10 15 20
Titr
atab
le ac
idity
cont
ent (
)
ControlPrecooling
Days of storage
(b)
ControlPrecooling
02
03
04
05
06
0 5 10 15 20
Solu
ble s
ugar
cont
ent (
)
Days of storage
(c)
ControlPrecooling
00
02
04
06
08
0 5 10 15 20
Star
ch co
nten
t (
)
Days of storage
(d)
FIGURE 4 Eects of forced air precooling treatment on TSS (a) TA (b) soluble sugar (c) and starch (d) content
Journal of Food Quality 7
Firmness is an important parameter in postharveststorage and marketing Loss of rmness caused by degra-dation of cell wall and starch may result in physical damagesin transportation and fruit susceptibility to pathogen attacks[2] In this study precooled fruits showed higher rmnessduring the entire storage It is in coincidence with previousstudy on waxberry and black mulberry fruits [1] It indicatedthat precooling treatment could retard mango fruitrsquos soft-ening and ripening and it might be related to the decreasedrespiration in the early of storage During postharvest rip-ening the chlorophyll content in mango peel decreased andthe peel color changes from green to yellow [28] Usually thepeel color was considered as an important indicator of fruitmaturity and a critical parameter in fruit marketing [29] Inthis study precooled fruits showed a lower yellow index andblowast value than control fruits and it was closely related to
higher chlorophyll a and chlorophyll b content in mangofruits peel during the storage [13] However the pigment inmango copyesh was not incopyuenced by precooling treatmentFruit weight loss is an important postharvest parameterincopyuencing fruit storage quality shelf-life and economicvalue In the current study however precooling treatmentpromoted fruit weight loss in storage at might be becausethat precooling treatment speeded water transpiration onmango fruitrsquos surface and enhanced fruit water loss Forcedair precooling was done without humidied air leading tohigher weight loss
After harvest mango fruits showed high respiration rateand metabolism activity which accelerated the consumptionof nutritional compounds and fruit ripening With fruitripening SSC and soluble sugar increase because of poly-saccharide hydrolysis while starch a vital polysaccharide in
0
2
4
6
8
10
0 5 10 15 20Days of storage
ControlTreatment
Rate
of O
2ndash pro
duct
ion
(nm
olmiddotg
ndash1middotF
Wmiddotm
inndash1
)
(a)
ControlTreatment
005
010
015
0 5 10 15 20
MD
A co
nten
t (nm
olmiddotg
ndash1middotF
W )
Days of storage
(b)
Figure 7 Eects of forced air precooling treatment on Ominus2 production (a) and MDA content (b)
0
20
40
60
80
100
10 15 20
Dec
ay in
cide
nce (
)
Days of storage
ControlPrecooling
(a)
ControlPrecooling
0
1
2
3
4
10 15 20
Dec
ay se
verit
y (
)
Days of storage
(b)
Figure 6 Eects of forced air precooling treatment on decay incidence (a) and decay severity (b)
8 Journal of Food Quality
fruit decreases continuously [30] In the current studyprecooled fruits showed lower SSC and higher starch contentduring the entire storage It indicated precooling treatmentretarded the hydrolysis of polysaccharides to SSC Mean-while starch degradation is closely related with fruit soft-ening Inhibiting the degradation of starch to SSC alsocontributed to the fruit rmness maintenance [15] econtent of TA represents the concentration of organic acidin fruits Fruit respiration can promote organic acid con-sumption and reduce TA content [31] During storage thecontent of TA in mango fruits decreased rapidly and pre-cooling treatment inhibited the tendency e change ofSSC TA and starch content might be related to the delay inthe ripening process and reduction of respiration rate Incoincidence with the previous study on apricot [10] pre-cooling treatment enhanced copyavonoids content in mangofruits in the late stage of storage Flavonoids content is animportant indicator of fruitrsquos antioxidant capacity [32] and
precooling treatment might contribute to mango fruitsantioxidant capacities However possible mechanisms needto be studied further
With the prolonging of storage fruit resistance topathogen decreases because of ripening and softening anddecay happens e current study found that precoolingtreatment reduced decay on mango fruits including decayincidence and decay index (decay severity) which is similarto the study on green asparagus and broccoli [33] It ispossible because that precooling treatment retarded mangofruit ripening and maintained fruit resistance to postharvestpathogens
Although reactive oxygen species (ROS) was benecial tothe improvement of plant disease resistance excessive ROScan aect DNA replication and protein synthesis resultingin fruit senescence [34] According to free radical theorysenescence was a process of active oxygen metabolismdisorders and accumulation When the fruits are forced by
0
10
20
30
40
0 5 10 15 20
CAT
activ
ity (U
middotgndash1
middotFW
middotmin
ndash1)
ControlTreatment
Days of storage
(a)
ControlTreatment
Days of storage
50
55
60
0 5 10 15 20
SOD
activ
ity (U
middotgndash1
middotFW
)
(b)
ControlTreatment
0
200
400
600
0 5 10 15 20
POD
activ
ity (U
middotgndash1
middotFW
middotmin
ndash1)
Days of storage
(c)
ControlTreatment
0
100
200
300
400
500
0 5 10 15 20
APX
activ
ity (U
middotgndash1
middotFW
middotmin
ndash1)
Days of storage
(d)
Figure 8 Eects of forced air precooling treatment on CAT (a) SOD (b) POD (c) and APX (d) activity
Journal of Food Quality 9
outside stresses reactive oxygen species metabolism balanceis broken free radicals are accumulated in abundance andthe peroxidation of membrane lipid is improved or aggra-vated all of which induce the fruit senescence [13] O2minus is akind of reactive oxygen species with relatively high viru-lence playing an important role in horticultural plant rip-ening and senescence processes particularly in membranedeterioration [35] is study showed that the O2minus pro-duction rate in mango fruits increased rapidly at the end ofstorage leading to senescence of mango Precooling treat-ment inhibited the increase of O2minus production rate andsubsequent fruit senescence Moreover being as the productof membrane lipid peroxidation MDA was usually used toevaluate the degree of membrane damage [36] and lipidperoxidation [37] In this study MDA content was increasedrapidly during the later storage period and was always at ahigher levelis veried that the mango fruitrsquos cellulose was
peroxidated and the integrity of the cell membrane wasdestroyed
ere are many active oxygen removal systems in planttissue e excessive active oxygen was eliminated by dif-ferent antioxidant enzymes [13] O2minus can be transformedinto H2O2 by SOD in the plants is study found thatprecooling treatment enhanced the SOD activity of mangofruits during storage at might be why precooled fruit hadlower O2minus production rate than control fruits In additionwe also found that precooled fruits had higher CAT andPOD activities than control fruits We could include thatprecooled fruits had lower reactive oxygen species thancontrol fruits However there was no signicant dierenceof APX between the precooled fruits and control fruits in thisstudy is could be due to the higher activity of CAT andPOD in mango fruits and APX had not played a major partin elimination of H2O2 erefore the balance betweenSOD POD CAT and APX activities in plants is importantfor determining the steady-state levels of H2O2 and ROS[38]
Glutathione (GSH) is also a very important kind of theactive oxygen removal material [35] In plant tissue GSHcan reduce dehydroascorbic acid (DHA) to ascorbic acid(ASA) and ASA can eliminate H2O2 directly Glutathionereductase (GR) is the key enzyme involved in the GSHgeneration from oxidized glutathione (GSSC) [13 35] isstudy showed that precooled fruits had a higher GSHcontent and GR activity than control fruits during thestorage all of which contributed to the delay of fruit ripeningand senescence
Previous reports indicated that PPO was directly relatedto browning and decay Decrease in its activity would lead toan induced resistance to browning and decay [25] In normalcircumstances PPO usually exists in organelles membraneand cell membrane so the PPO activity is low [13]When thestructure of cell membrane is destroyed PPO is released andthe activity increases In this study the PPO activity in
20
40
60
80
0 5 10 15 20
GSH
cont
ent (
nmol
middotgndash1
middotFW
)
Days of storage
ControlTreatment
(a)
ControlTreatment
0
100
200
300
0 5 10 15 20
GR
activ
ity (U
middotgndash1
middotFW
middotmin
ndash1)
Days of storage
(b)
Figure 9 Eects of forced air precooling treatment on GSH content (a) and GR activity (b)
0
2
4
6
8
10
12
14
0 5 10 15 20
PPO
activ
ity (U
middotgndash1
middotFW
middotmin
ndash1)
Days of storage
ControlTreatment
Figure 10 Eects of forced air precooling treatment on PPOactivity
10 Journal of Food Quality
precooled fruits was always kept in a low level and thismight be because the precooling treatment enhanced theantioxidant defense capabilities and helped to maintain cellintegrity
5 Conclusion
Mango fruitrsquos quality was significantly improved by forcedair precooling treatment Precooling treatment delayed fruitripening and senescence with inhibition of ROS and en-hancement of active oxygen removal enzymes such as su-peroxide dismutase (SOD) catalase (CAT) peroxidase(POD) glutathione reductase (GR) and polyphenoloxidase(PPO) e firmness was maintained and fruit decay wasinhibited during storage ese results indicate that forcedair precooling treatment could maintain mango fruitrsquosquality by enhancing antioxidant activity and delaying fruitripening erefore it is suggested that mango fruits shouldbe precooled immediately after harvest for maintaining fruitquality and prolonging shelf-life
Data Availability
e data used to support the findings of this study areavailable from the corresponding author upon request
Conflicts of Interest
e authors declare that there are no conflicts of interestassociated with the publication of this manuscript
Acknowledgments
is research was supported by Support Project of High-Level Teachers in Beijing Municipal Universities in thePeriod of the 13th Five-Year Plan (CITampTCD201704037)Construction of Scientific Research Innovation ServiceAbility-Basic Scientific Research Operating Expense-FoodFeature Project (PXM2018_014213_000033) and SupportProject of High-Level Teachers in Beijing Municipal Uni-versities (IDHT20180506)
References
[1] Q Han H Gao H Chen X Fang and W Wu ldquoPrecoolingand ozone treatments affects postharvest quality of blackmulberry (Morus nigra) fruitsrdquo Food Chemistry vol 221pp 1947ndash1953 2017
[2] G M Cosme Silva W B Silva D B Medeiros et al ldquoechitosan affects severely the carbon metabolism in mango(Mangifera indica L cv Palmer) fruit during storagerdquo FoodChemistry vol 237 pp 372ndash378 2017
[3] J Li Q Li X J Lei et al ldquoEffects of wax coating on themoisture loss of cucumbers at different storage temperaturesrdquoJournal of food quality vol 2018 no 12 pp 1ndash6 2018
[4] H J Zhou Z W YE M S Su and J H Du ldquoEffects of lowtemperature and forced air precooling on precooling per-formance of different varieties of peach fruitsrdquo Storage ampProcess vol 15 pp 16ndash19 2015
[5] A Rab H Rehman I Haq M Sajid K Nawab and K AlildquoHarvest stages and pre-cooling influence the quality and
storage life of tomato fruitrdquo Journal Animal amp Plant Sciencevol 23 no 5 pp 1347ndash1357 2013
[6] M Zhou K H Ndeurumio L Zhao and Z Hu ldquoImpact ofprecooling and controlled-atmosphere storage on γ--aminobutyric acid (GABA) accumulation in longan (dimo-carpus longan lour) fruitrdquo Journal of Agricultural and FoodChemistry vol 64 no 33 pp 6443ndash6450 2016
[7] D Martinez-Romero S Castillo and D Valero ldquoForced aircooling applied before fruit handling to prevent mechanicaldamage of plums (Prunus salicina Lindl)rdquo Postharvest Biologyamp Technology vol 28 no 1 pp 135ndash142 2003
[8] H Nalbandi S Seiiedlou H R Ghasemzadeh andF Rangbar ldquoInnovative parallel airflow system for forced-aircooling of strawberriesrdquo Food and Bioproducts Processingvol 100 pp 440ndash449 2016
[9] J L OrsquoSullivan M J Ferrua R Love P VerbovenB Nicolaı and A East ldquoForced air cooling of polylinedhorticultural produce optimal cooling conditions andpackage designrdquo Postharvest Biology amp Technology vol 126pp 67ndash75 2017
[10] J Yan Y Song J Li and W Jiang ldquoForced-air precoolingtreatment enhanced antioxidant capacities of apricotsrdquoJournal of Food Processing and Preservation vol 42 no 1article e13320 2018
[11] M Jincy M Djanaguiraman P JeyakumarK S Subramanian S Jayasankar and G Paliyath ldquoInhibitionof phospholipase D enzyme activity through hexanal leads todelayed mango (Mangifera indica L) fruit ripening throughchanges in oxidants and antioxidant enzymes activityrdquo Sci-entia Horticulturae vol 218 pp 316ndash325 2017
[12] J Li G W Ma L Ma et al ldquoMultivariate analysis of fruitantioxidant activities of blackberry treated with 1-Methyl-cyclopropene or vacuum precoolingrdquo International Journal ofAnalytical Chemistry vol 2018 Article ID 2416461 5 pages2018
[13] P Sharma A B Jha R S Dubey andM Pessarakli ldquoReactiveoxygen species oxidative damage and antioxidative defensemechanism in plants under stressful conditionsrdquo Journal ofBotany vol 2012 Article ID 217037 26 pages 2012
[14] O Elloumi M Ghrab andM BenMimoun ldquoEffects of flowerbuds removal on seasonal starch storage and mobilization infruiting and non-fruiting branches of pistachio trees cvMateur under dry and warm climaterdquo Scientia Horticulturaevol 172 no 3 pp 19ndash25 2014
[15] K Liu J Liu H Li C Yuan J Zhong and Y Chen ldquoInfluenceof postharvest citric acid and chitosan coating treatment onripening attributes and expression of cell wall related genes incherimoya (Annona cherimola Mill) fruitrdquo Scientia Horti-culturae vol 198 no 10 pp 1ndash11 2016
[16] D M Hodges J M Delong C F Forney and R K PrangeldquoImproving the thiobarbituric acid-reactive-substances assayfor estimating lipid peroxidation in plant tissues containinganthocyanin and other interfering compoundsrdquo Plantavol 207 no 4 pp 604ndash611 1999
[17] J E Brehe andH B Burch ldquoEnzymatic assay for glutathionerdquoAnalytical Biochemistry vol 74 no 1 pp 189ndash197 1976
[18] D Prochazkova R K Sairam G C Srivastava andD V Singh ldquoOxidative stress and antioxidant activity as thebasis of senescence in maize leavesrdquo Plant Science vol 161no 4 pp 765ndash771 2001
[19] C Larrigaudiere I Lentheric J Puy and E Pinto ldquoBio-chemical characterisation of core browning and brown heartdisorders in pear bymultivariate analysisrdquo Postharvest Biologyand Technology vol 31 no 1 pp 29ndash39 2004
Journal of Food Quality 11
[20] S Naima M R Khan and S Maria ldquoAntioxidant activitytotal phenolic and total flavonoid contents of whole plantextracts Torilis leptophylla Lrdquo BMC Complementary and Al-ternative Medicine vol 12 no 1 p 221 2012
[21] Y Nakano and K Asada ldquoPurification of ascorbate peroxi-dase in spinach chloroplasts its inactivation in ascorbate-depleted medium and reactivation by monodehydroascorbateradicalrdquo Plant amp Cell Physiology vol 28 no 1 pp 131ndash1401987
[22] C H Foyer and B Halliwell ldquoe presence of glutathione andglutathione reductase in chloroplasts a proposed role inascorbic acid metabolismrdquo Planta vol 133 no 1 pp 21ndash251976
[23] F Zhu Z Yun Q Ma et al ldquoEffects of exogenous 24-epi-brassinolide treatment on postharvest quality and resistanceof Satsuma Mandarin (Citrus unshiu)rdquo Postharvest Biologyand Technology vol 100 pp 8ndash15 2015
[24] S Zhu and B Ma ldquoBenzothiadiazole- or methyl jasmonate-induced resistance toColletotrichum musaein harvested ba-nana fruit is related to elevated defense enzyme activitiesrdquolteJournal of Horticultural Science and Biotechnology vol 82no 4 pp 500ndash506 2007
[25] J-W Han J-P Qian C-J Zhao X-T Yang and B-L FanldquoMathematical modelling of cooling efficiency of ventilatedpackaging integral performance evaluationrdquo InternationalJournal of Heat andMass Transfer vol 111 pp 386ndash397 2017
[26] X Zheng L Ye T Jiang G Jing and J Li ldquoLimiting thedeterioration of mango fruit during storage at room tem-perature by oxalate treatmentrdquo Food Chemistry vol 130no 2 pp 279ndash285 2012
[27] J K Dhemre D P Waskar S D Masalkar andR S Gaikwad ldquoEffect of post-harvest treatments on shelf lifeand quality of mango cv Kesar in cool storage and ambientconditionsrdquo Agricultural Science Digest vol 25 no 2pp 79ndash84 2005
[28] M Fleancu ldquoCorrelations among some physiological pro-cesses in apple fruit during growing and maturation pro-cessesrdquo International Journal of Agriculture amp Biologyvol 8530 pp 9ndash4 2007
[29] H Vergara-Domınguez J J Rıos B Gandul-Rojas andM Roca ldquoChlorophyll catabolism in olive fruits (var Arbe-quina and Hojiblanca) during maturationrdquo Food Chemistryvol 212 pp 604ndash611 2016
[30] S S Zaharah and Z Singh ldquoPostharvest nitric oxide fumi-gation alleviates chilling injury delays fruit ripening andmaintains quality in cold-stored ldquoKensington Priderdquo mangordquoPostharvest Biology and Technology vol 60 no 3 pp 202ndash210 2011
[31] M Babalar M Asghari A Talaei and A Khosroshahi ldquoEffectof pre- and postharvest salicylic acid treatment on ethyleneproduction fungal decay and overall quality of Selva strawberryfruitrdquo Food Chemistry vol 105 no 2 pp 449ndash453 2007
[32] A Ali M K Ong and C F Forney ldquoEffect of ozone pre-conditioning on quality and antioxidant capacity of papayafruit during ambient storagerdquo Food Chemistry vol 142 no 2pp 19ndash26 2014
[33] X Wang S Gu and B Chen ldquoe mechanism of cholesterol-effect on the quality of green asparagus (Asparagus officinalisL) spears during low temperature storagerdquo Scientia Horti-culturae vol 231 pp 36ndash42 2018
[34] M Sivapriya and S Leela ldquoIsolation and purification of anovel antioxidant protein from the water extract of Sundakai(Solanum torvum) seedsrdquo Food Chemistry vol 104 no 2pp 510ndash517 2007
[35] F V Breusegem E Vranova J F Dat and D Inze ldquoe roleof active oxygen species in plant signal transductionrdquo PlantScience vol 161 no 3 pp 405ndash414 2001
[36] L M Segal and R A Wilson ldquoReactive oxygen speciesmetabolism and plant-fungal interactionsrdquo Fungal Geneticsand Biology vol 110 pp 1ndash9 2018
[37] Y Wang X Xie and L E Long ldquoe effect of postharvestcalcium application in hydro-cooling water on tissue calciumcontent biochemical changes and quality attributes of sweetcherry fruitrdquo Food Chemistry vol 160 no 11 pp 22ndash30 2014
[38] Y Imahori J Bai and E Baldwin ldquoAntioxidative responses ofripe tomato fruit to postharvest chilling and heating treat-mentsrdquo Scientia Horticulturae vol 198 no 75 pp 398ndash4062016
difference between precooled and control fruit was notsignificant at the end of storage
Llowast value from low to high indicates that the lightnessincreases Llowast value of mango fruits peel increased with theprolonging of the storage time Llowast value in precooled fruitswas lower than control fruits during the entire storageperiod On the 10th day the Llowast value of precooled fruits was115 lower than that of control fruits (Figure 2(b)) alowast valuefrom negative to positive represents that the color changesfrom green to red and blowast was from blue to yellow With theextension of storage alowast and blowast values of mango fruits peelwere all increased steadily which showed that the peel colorwas changing from green to yellow Precooling treatmentretarded the increase of alowast and blowast during the beginning ofthe storage On the 10th day precooled fruits had 478lower alowast and 149 lower blowast than that of control fruitsrespectively (Plt 005) e differences between precooledand control fruits were not significant at the end of storage(Figures 2(c) and 2(d))
314 Pigment Content Figure 3 showed pigment changes inmango fruit flesh and peel With the ripening of mangofruits chlorophyll a in mango fruits peel decreased dra-matically and the decrease of control fruits was higher thanprecooled fruits On the 20th day of storage precooled fruitspeel had 84 higher chlorophyll a than control fruits(Figure 3(a)) Chlorophyll a in mango fruits flesh was alsodecreased dramatically On the 10th day precooled fruitsfresh had a significantly higher level of chlorophyll a thanthat of control fruits At other times there was no significantdifference (Figure 3(b))
e change tendency of chlorophyll b in mango fruitspeel was similar to chlorophyll a and precooling treatmentalso retarded chlorophyll b reduction On the 15th and 20thday of storage precooled fruits peel had 188 and 200higher chlorophyll b than that of control fruits re-spectively (Figure 3(c)) However there was no significantdifference in chlorophyll b between precooled fruitsflesh and control fruits flesh during the storage period(Figure 3(d))
32 Effects of Forced Air Precooling on Internal Quality ofMango Fruits during Storage
321 Total Soluble Solids As shown in Figure 4(a) TSS ofcontrol fruits increased during the first 15 days and thendecreased Precooling treatment retarded the increase ofTSS and there was no decrease until the end of storageerefore on the 20th day of storage the TSS in precooledfruits was 116 higher than the control
322 Titratable Acidity Figure 4(b) showed the changes ofTA content in mango fruits during storage TA in mangofruits changed slightly during first 10 days after which TAdecreased rapidly Precooled fruits exhibited less decreasecompared to the control On the 15th day precooled fruitshad 395 higher TA content than control fruits
323 Soluble Sugar Content Soluble sugar content ofmango fruits in both precooled fruits and control fruitsincreased steadily with the increase of storage time At thebeginning of storage soluble sugar content in precooledfruits was slightly lower than that of control fruits At the endof the storage however soluble sugar content in precooledfruits was slightly higher than that of controls fruit But therewas no significant difference between the two groups(Figure 4(c))
324 Starch Content Figure 4(d) showed that starchcontent decreased continuously during the whole storageperiod On the 20th day starch content was only 25 of theinitial value Precooling treatment delayed the decrease ofstarch content during the beginning of the storage periodOn the 5th 10th and 15th precooled fruits had 273 223and 377 higher starch content than the control grouprespectively
325 Flavonoid Content As shown in Figure 5 flavonoidscontent was decreased in both precooled and control fruitsand then increased slightly at the first 5 days Flavonoid inprecooled fruits increased more rapidly than that in thecontrol On the 10th 15th and 20th day precooled fruits had103 112 and 61 higher flavonoids content thancontrol respectively
33 Effects of Forced Air Precooling Treatment on Decay In-cidence and Decay Severity of Mango Fruits during StorageDecay incidence and decay severity of mango fruits that werestored at 13degC and 85sim95 RH was shown in Figures 6(a)and 6(b) Precooling treatment decreased fruit decay in bothdecay incidence and decay index On the 20th day precooledfruits had 397 lower decay rate and 413 lower decayindex than control fruits respectively
34 Effects of Forced Air Precooling Treatment on ReactiveOxygen Species and Related Enzymes of MangoFruits during Storage
341 O2minus Production ere was no significant change ofO2minus production rate in mango fruits during the beginning ofstorage After 10 days rate of O2minus production in controlfruits increased rapidly and suddenly while that in pre-cooled fruits increased slightly On the 15th and 20th day rateof O2minus production in precooled fruits was only 678 and645 of control fruits respectively (Figure 7(a))
342 Malondialdehyde Content Figure 7(b) showed thatMDA content in control fruits increased rapidly at the first5 days of storage and then kept steady while MDA contentin precooled fruits increased steadily during the wholestorage On the 5th and 10th day MDA content in precooledfruits was only 661 and 802 of that in control fruits Inthe storage period MDA content of precooled fruits wasgradually close to the control At the end of the storage
Journal of Food Quality 5
period there was no signicant dierence between theMDAcontent of two groups
343 Superoxide Catalase Peroxidase and Ascorbic Per-oxidase Activities As shown in Figure 8 during the wholestorage period the activities of SOD CAT POD and APXin mango fruits showed a constant increase tendencyPrecooled fruits exhibited higher SOD and CAT activitiesin the entire storage period On the 20th day treated fruitshad 232 higher CAT activity and 27 higher SOD ac-tivity than control fruits respectively (Figures 8(a) and8(b))
Precooling treatment enhanced POD activity in mangofruits except on the 5th day of storage On the 15th and 20thday of storage precooled fruits had 236 and 105 higherPOD activity than control fruits respectively (Figure 8(c))At the beginning of storage precooled fruits showed higherAPX activity which was 1266 higher than the controlWhile at the end of storage precooling treatment had no
signicant incopyuence on APX activity in mango fruits(Figure 8(d))
344 Glutathione Content and Glutathione ReductaseActivity As shown in Figure 9(a) GSH content in mangofruits showed a gradually increase during rst 10 days andthen decreased slowly Precooled fruits had higher GSHcontent than control fruits during the whole storage On the10th and 15th day of storage treated fruits had 221 and127 higher GSH content than control fruits respectively
GR activity in mango fruits increased with the pro-longing of the storage time Precooled fruits had lower GRactivity than control fruits at earlier storage At the end of thestorage the GR activity in precooled fruits was slightlyhigher but the dierence was not signicant (Pgt 005Figure 9(b))
345 Polyphenoloxidase Activity As shown in Figure 10PPO activity in control fruits increased dramatically at
0
2
4
6
8
0 5 10 15 20
Chlo
roph
yll a
cont
ent
(mgmiddot
100g
ndash1middotF
W)
ControlPrecooling
Days of storage
(a)
Chlo
roph
yll a
cont
ent
(mgmiddot
100g
ndash1middotF
W)
ControlPrecooling
00
02
04
06
0 5 10 15 20Days of storage
(b)
Chlo
roph
yll b
cont
ent
(mgmiddot
100g
ndash1middotF
W)
ControlPrecooling
00
05
10
15
20
25
0 5 10 15 20Days of storage
(c)
Chlo
roph
yll b
cont
ent
(mgmiddot
100g
ndash1middotF
W)
ControlPrecooling
00
01
02
0 5 10 15 20Days of storage
(d)
Figure 3 Eects of forced air precooling treatment on chlorophyll a of peel (a) and copyesh (b) and chlorophyll b of mango fruit peel (c) and copyesh(d)
6 Journal of Food Quality
earlier storage and had a peak activity on the 5th day ofstorage after which PPO activity decreased and was keptstable PPO activity in precooled fruits was always at a lowerlevel On the 5th day and 20th day precooled fruits had 819and 674 lower PPO activity than control fruitsrespectively
4 Discussion
Mango fruits are a typical climacteric fruit and commonlyharvested at a green mature stage to prevent the postharvestloss [25] After harvest fruits begin to ripe with the char-acteristic changes on peel coloration textural softeningsugar maintenance suer from over softening and ripeningduring storage which result in postharvest quality de-terioration and short shelf-life [26] In this study the resultsshowed that precooling treatment could retard fruit soft-ening peel coloration accumulation of sugar and organicacid and disease development on mango fruits and all ofwhich were closely related to the maintenance of fruitripening [27]
04
05
06
07
08
09
10
0 5 10 15 20
Flav
onoi
ds co
nten
t (O
D32
5 gndash1
middotFW
)
Days of storage
ControlPrecooling
Figure 5 Eects of forced air precooling treatment on copyavonoidcontent
4
8
12
16
20
0 5 10 15 20
Tota
l sol
uble
solid
s (
)
ControlPrecooling
Days of storage
(a)
0
1
2
0 5 10 15 20
Titr
atab
le ac
idity
cont
ent (
)
ControlPrecooling
Days of storage
(b)
ControlPrecooling
02
03
04
05
06
0 5 10 15 20
Solu
ble s
ugar
cont
ent (
)
Days of storage
(c)
ControlPrecooling
00
02
04
06
08
0 5 10 15 20
Star
ch co
nten
t (
)
Days of storage
(d)
FIGURE 4 Eects of forced air precooling treatment on TSS (a) TA (b) soluble sugar (c) and starch (d) content
Journal of Food Quality 7
Firmness is an important parameter in postharveststorage and marketing Loss of rmness caused by degra-dation of cell wall and starch may result in physical damagesin transportation and fruit susceptibility to pathogen attacks[2] In this study precooled fruits showed higher rmnessduring the entire storage It is in coincidence with previousstudy on waxberry and black mulberry fruits [1] It indicatedthat precooling treatment could retard mango fruitrsquos soft-ening and ripening and it might be related to the decreasedrespiration in the early of storage During postharvest rip-ening the chlorophyll content in mango peel decreased andthe peel color changes from green to yellow [28] Usually thepeel color was considered as an important indicator of fruitmaturity and a critical parameter in fruit marketing [29] Inthis study precooled fruits showed a lower yellow index andblowast value than control fruits and it was closely related to
higher chlorophyll a and chlorophyll b content in mangofruits peel during the storage [13] However the pigment inmango copyesh was not incopyuenced by precooling treatmentFruit weight loss is an important postharvest parameterincopyuencing fruit storage quality shelf-life and economicvalue In the current study however precooling treatmentpromoted fruit weight loss in storage at might be becausethat precooling treatment speeded water transpiration onmango fruitrsquos surface and enhanced fruit water loss Forcedair precooling was done without humidied air leading tohigher weight loss
After harvest mango fruits showed high respiration rateand metabolism activity which accelerated the consumptionof nutritional compounds and fruit ripening With fruitripening SSC and soluble sugar increase because of poly-saccharide hydrolysis while starch a vital polysaccharide in
0
2
4
6
8
10
0 5 10 15 20Days of storage
ControlTreatment
Rate
of O
2ndash pro
duct
ion
(nm
olmiddotg
ndash1middotF
Wmiddotm
inndash1
)
(a)
ControlTreatment
005
010
015
0 5 10 15 20
MD
A co
nten
t (nm
olmiddotg
ndash1middotF
W )
Days of storage
(b)
Figure 7 Eects of forced air precooling treatment on Ominus2 production (a) and MDA content (b)
0
20
40
60
80
100
10 15 20
Dec
ay in
cide
nce (
)
Days of storage
ControlPrecooling
(a)
ControlPrecooling
0
1
2
3
4
10 15 20
Dec
ay se
verit
y (
)
Days of storage
(b)
Figure 6 Eects of forced air precooling treatment on decay incidence (a) and decay severity (b)
8 Journal of Food Quality
fruit decreases continuously [30] In the current studyprecooled fruits showed lower SSC and higher starch contentduring the entire storage It indicated precooling treatmentretarded the hydrolysis of polysaccharides to SSC Mean-while starch degradation is closely related with fruit soft-ening Inhibiting the degradation of starch to SSC alsocontributed to the fruit rmness maintenance [15] econtent of TA represents the concentration of organic acidin fruits Fruit respiration can promote organic acid con-sumption and reduce TA content [31] During storage thecontent of TA in mango fruits decreased rapidly and pre-cooling treatment inhibited the tendency e change ofSSC TA and starch content might be related to the delay inthe ripening process and reduction of respiration rate Incoincidence with the previous study on apricot [10] pre-cooling treatment enhanced copyavonoids content in mangofruits in the late stage of storage Flavonoids content is animportant indicator of fruitrsquos antioxidant capacity [32] and
precooling treatment might contribute to mango fruitsantioxidant capacities However possible mechanisms needto be studied further
With the prolonging of storage fruit resistance topathogen decreases because of ripening and softening anddecay happens e current study found that precoolingtreatment reduced decay on mango fruits including decayincidence and decay index (decay severity) which is similarto the study on green asparagus and broccoli [33] It ispossible because that precooling treatment retarded mangofruit ripening and maintained fruit resistance to postharvestpathogens
Although reactive oxygen species (ROS) was benecial tothe improvement of plant disease resistance excessive ROScan aect DNA replication and protein synthesis resultingin fruit senescence [34] According to free radical theorysenescence was a process of active oxygen metabolismdisorders and accumulation When the fruits are forced by
0
10
20
30
40
0 5 10 15 20
CAT
activ
ity (U
middotgndash1
middotFW
middotmin
ndash1)
ControlTreatment
Days of storage
(a)
ControlTreatment
Days of storage
50
55
60
0 5 10 15 20
SOD
activ
ity (U
middotgndash1
middotFW
)
(b)
ControlTreatment
0
200
400
600
0 5 10 15 20
POD
activ
ity (U
middotgndash1
middotFW
middotmin
ndash1)
Days of storage
(c)
ControlTreatment
0
100
200
300
400
500
0 5 10 15 20
APX
activ
ity (U
middotgndash1
middotFW
middotmin
ndash1)
Days of storage
(d)
Figure 8 Eects of forced air precooling treatment on CAT (a) SOD (b) POD (c) and APX (d) activity
Journal of Food Quality 9
outside stresses reactive oxygen species metabolism balanceis broken free radicals are accumulated in abundance andthe peroxidation of membrane lipid is improved or aggra-vated all of which induce the fruit senescence [13] O2minus is akind of reactive oxygen species with relatively high viru-lence playing an important role in horticultural plant rip-ening and senescence processes particularly in membranedeterioration [35] is study showed that the O2minus pro-duction rate in mango fruits increased rapidly at the end ofstorage leading to senescence of mango Precooling treat-ment inhibited the increase of O2minus production rate andsubsequent fruit senescence Moreover being as the productof membrane lipid peroxidation MDA was usually used toevaluate the degree of membrane damage [36] and lipidperoxidation [37] In this study MDA content was increasedrapidly during the later storage period and was always at ahigher levelis veried that the mango fruitrsquos cellulose was
peroxidated and the integrity of the cell membrane wasdestroyed
ere are many active oxygen removal systems in planttissue e excessive active oxygen was eliminated by dif-ferent antioxidant enzymes [13] O2minus can be transformedinto H2O2 by SOD in the plants is study found thatprecooling treatment enhanced the SOD activity of mangofruits during storage at might be why precooled fruit hadlower O2minus production rate than control fruits In additionwe also found that precooled fruits had higher CAT andPOD activities than control fruits We could include thatprecooled fruits had lower reactive oxygen species thancontrol fruits However there was no signicant dierenceof APX between the precooled fruits and control fruits in thisstudy is could be due to the higher activity of CAT andPOD in mango fruits and APX had not played a major partin elimination of H2O2 erefore the balance betweenSOD POD CAT and APX activities in plants is importantfor determining the steady-state levels of H2O2 and ROS[38]
Glutathione (GSH) is also a very important kind of theactive oxygen removal material [35] In plant tissue GSHcan reduce dehydroascorbic acid (DHA) to ascorbic acid(ASA) and ASA can eliminate H2O2 directly Glutathionereductase (GR) is the key enzyme involved in the GSHgeneration from oxidized glutathione (GSSC) [13 35] isstudy showed that precooled fruits had a higher GSHcontent and GR activity than control fruits during thestorage all of which contributed to the delay of fruit ripeningand senescence
Previous reports indicated that PPO was directly relatedto browning and decay Decrease in its activity would lead toan induced resistance to browning and decay [25] In normalcircumstances PPO usually exists in organelles membraneand cell membrane so the PPO activity is low [13]When thestructure of cell membrane is destroyed PPO is released andthe activity increases In this study the PPO activity in
20
40
60
80
0 5 10 15 20
GSH
cont
ent (
nmol
middotgndash1
middotFW
)
Days of storage
ControlTreatment
(a)
ControlTreatment
0
100
200
300
0 5 10 15 20
GR
activ
ity (U
middotgndash1
middotFW
middotmin
ndash1)
Days of storage
(b)
Figure 9 Eects of forced air precooling treatment on GSH content (a) and GR activity (b)
0
2
4
6
8
10
12
14
0 5 10 15 20
PPO
activ
ity (U
middotgndash1
middotFW
middotmin
ndash1)
Days of storage
ControlTreatment
Figure 10 Eects of forced air precooling treatment on PPOactivity
10 Journal of Food Quality
precooled fruits was always kept in a low level and thismight be because the precooling treatment enhanced theantioxidant defense capabilities and helped to maintain cellintegrity
5 Conclusion
Mango fruitrsquos quality was significantly improved by forcedair precooling treatment Precooling treatment delayed fruitripening and senescence with inhibition of ROS and en-hancement of active oxygen removal enzymes such as su-peroxide dismutase (SOD) catalase (CAT) peroxidase(POD) glutathione reductase (GR) and polyphenoloxidase(PPO) e firmness was maintained and fruit decay wasinhibited during storage ese results indicate that forcedair precooling treatment could maintain mango fruitrsquosquality by enhancing antioxidant activity and delaying fruitripening erefore it is suggested that mango fruits shouldbe precooled immediately after harvest for maintaining fruitquality and prolonging shelf-life
Data Availability
e data used to support the findings of this study areavailable from the corresponding author upon request
Conflicts of Interest
e authors declare that there are no conflicts of interestassociated with the publication of this manuscript
Acknowledgments
is research was supported by Support Project of High-Level Teachers in Beijing Municipal Universities in thePeriod of the 13th Five-Year Plan (CITampTCD201704037)Construction of Scientific Research Innovation ServiceAbility-Basic Scientific Research Operating Expense-FoodFeature Project (PXM2018_014213_000033) and SupportProject of High-Level Teachers in Beijing Municipal Uni-versities (IDHT20180506)
References
[1] Q Han H Gao H Chen X Fang and W Wu ldquoPrecoolingand ozone treatments affects postharvest quality of blackmulberry (Morus nigra) fruitsrdquo Food Chemistry vol 221pp 1947ndash1953 2017
[2] G M Cosme Silva W B Silva D B Medeiros et al ldquoechitosan affects severely the carbon metabolism in mango(Mangifera indica L cv Palmer) fruit during storagerdquo FoodChemistry vol 237 pp 372ndash378 2017
[3] J Li Q Li X J Lei et al ldquoEffects of wax coating on themoisture loss of cucumbers at different storage temperaturesrdquoJournal of food quality vol 2018 no 12 pp 1ndash6 2018
[4] H J Zhou Z W YE M S Su and J H Du ldquoEffects of lowtemperature and forced air precooling on precooling per-formance of different varieties of peach fruitsrdquo Storage ampProcess vol 15 pp 16ndash19 2015
[5] A Rab H Rehman I Haq M Sajid K Nawab and K AlildquoHarvest stages and pre-cooling influence the quality and
storage life of tomato fruitrdquo Journal Animal amp Plant Sciencevol 23 no 5 pp 1347ndash1357 2013
[6] M Zhou K H Ndeurumio L Zhao and Z Hu ldquoImpact ofprecooling and controlled-atmosphere storage on γ--aminobutyric acid (GABA) accumulation in longan (dimo-carpus longan lour) fruitrdquo Journal of Agricultural and FoodChemistry vol 64 no 33 pp 6443ndash6450 2016
[7] D Martinez-Romero S Castillo and D Valero ldquoForced aircooling applied before fruit handling to prevent mechanicaldamage of plums (Prunus salicina Lindl)rdquo Postharvest Biologyamp Technology vol 28 no 1 pp 135ndash142 2003
[8] H Nalbandi S Seiiedlou H R Ghasemzadeh andF Rangbar ldquoInnovative parallel airflow system for forced-aircooling of strawberriesrdquo Food and Bioproducts Processingvol 100 pp 440ndash449 2016
[9] J L OrsquoSullivan M J Ferrua R Love P VerbovenB Nicolaı and A East ldquoForced air cooling of polylinedhorticultural produce optimal cooling conditions andpackage designrdquo Postharvest Biology amp Technology vol 126pp 67ndash75 2017
[10] J Yan Y Song J Li and W Jiang ldquoForced-air precoolingtreatment enhanced antioxidant capacities of apricotsrdquoJournal of Food Processing and Preservation vol 42 no 1article e13320 2018
[11] M Jincy M Djanaguiraman P JeyakumarK S Subramanian S Jayasankar and G Paliyath ldquoInhibitionof phospholipase D enzyme activity through hexanal leads todelayed mango (Mangifera indica L) fruit ripening throughchanges in oxidants and antioxidant enzymes activityrdquo Sci-entia Horticulturae vol 218 pp 316ndash325 2017
[12] J Li G W Ma L Ma et al ldquoMultivariate analysis of fruitantioxidant activities of blackberry treated with 1-Methyl-cyclopropene or vacuum precoolingrdquo International Journal ofAnalytical Chemistry vol 2018 Article ID 2416461 5 pages2018
[13] P Sharma A B Jha R S Dubey andM Pessarakli ldquoReactiveoxygen species oxidative damage and antioxidative defensemechanism in plants under stressful conditionsrdquo Journal ofBotany vol 2012 Article ID 217037 26 pages 2012
[14] O Elloumi M Ghrab andM BenMimoun ldquoEffects of flowerbuds removal on seasonal starch storage and mobilization infruiting and non-fruiting branches of pistachio trees cvMateur under dry and warm climaterdquo Scientia Horticulturaevol 172 no 3 pp 19ndash25 2014
[15] K Liu J Liu H Li C Yuan J Zhong and Y Chen ldquoInfluenceof postharvest citric acid and chitosan coating treatment onripening attributes and expression of cell wall related genes incherimoya (Annona cherimola Mill) fruitrdquo Scientia Horti-culturae vol 198 no 10 pp 1ndash11 2016
[16] D M Hodges J M Delong C F Forney and R K PrangeldquoImproving the thiobarbituric acid-reactive-substances assayfor estimating lipid peroxidation in plant tissues containinganthocyanin and other interfering compoundsrdquo Plantavol 207 no 4 pp 604ndash611 1999
[17] J E Brehe andH B Burch ldquoEnzymatic assay for glutathionerdquoAnalytical Biochemistry vol 74 no 1 pp 189ndash197 1976
[18] D Prochazkova R K Sairam G C Srivastava andD V Singh ldquoOxidative stress and antioxidant activity as thebasis of senescence in maize leavesrdquo Plant Science vol 161no 4 pp 765ndash771 2001
[19] C Larrigaudiere I Lentheric J Puy and E Pinto ldquoBio-chemical characterisation of core browning and brown heartdisorders in pear bymultivariate analysisrdquo Postharvest Biologyand Technology vol 31 no 1 pp 29ndash39 2004
Journal of Food Quality 11
[20] S Naima M R Khan and S Maria ldquoAntioxidant activitytotal phenolic and total flavonoid contents of whole plantextracts Torilis leptophylla Lrdquo BMC Complementary and Al-ternative Medicine vol 12 no 1 p 221 2012
[21] Y Nakano and K Asada ldquoPurification of ascorbate peroxi-dase in spinach chloroplasts its inactivation in ascorbate-depleted medium and reactivation by monodehydroascorbateradicalrdquo Plant amp Cell Physiology vol 28 no 1 pp 131ndash1401987
[22] C H Foyer and B Halliwell ldquoe presence of glutathione andglutathione reductase in chloroplasts a proposed role inascorbic acid metabolismrdquo Planta vol 133 no 1 pp 21ndash251976
[23] F Zhu Z Yun Q Ma et al ldquoEffects of exogenous 24-epi-brassinolide treatment on postharvest quality and resistanceof Satsuma Mandarin (Citrus unshiu)rdquo Postharvest Biologyand Technology vol 100 pp 8ndash15 2015
[24] S Zhu and B Ma ldquoBenzothiadiazole- or methyl jasmonate-induced resistance toColletotrichum musaein harvested ba-nana fruit is related to elevated defense enzyme activitiesrdquolteJournal of Horticultural Science and Biotechnology vol 82no 4 pp 500ndash506 2007
[25] J-W Han J-P Qian C-J Zhao X-T Yang and B-L FanldquoMathematical modelling of cooling efficiency of ventilatedpackaging integral performance evaluationrdquo InternationalJournal of Heat andMass Transfer vol 111 pp 386ndash397 2017
[26] X Zheng L Ye T Jiang G Jing and J Li ldquoLimiting thedeterioration of mango fruit during storage at room tem-perature by oxalate treatmentrdquo Food Chemistry vol 130no 2 pp 279ndash285 2012
[27] J K Dhemre D P Waskar S D Masalkar andR S Gaikwad ldquoEffect of post-harvest treatments on shelf lifeand quality of mango cv Kesar in cool storage and ambientconditionsrdquo Agricultural Science Digest vol 25 no 2pp 79ndash84 2005
[28] M Fleancu ldquoCorrelations among some physiological pro-cesses in apple fruit during growing and maturation pro-cessesrdquo International Journal of Agriculture amp Biologyvol 8530 pp 9ndash4 2007
[29] H Vergara-Domınguez J J Rıos B Gandul-Rojas andM Roca ldquoChlorophyll catabolism in olive fruits (var Arbe-quina and Hojiblanca) during maturationrdquo Food Chemistryvol 212 pp 604ndash611 2016
[30] S S Zaharah and Z Singh ldquoPostharvest nitric oxide fumi-gation alleviates chilling injury delays fruit ripening andmaintains quality in cold-stored ldquoKensington Priderdquo mangordquoPostharvest Biology and Technology vol 60 no 3 pp 202ndash210 2011
[31] M Babalar M Asghari A Talaei and A Khosroshahi ldquoEffectof pre- and postharvest salicylic acid treatment on ethyleneproduction fungal decay and overall quality of Selva strawberryfruitrdquo Food Chemistry vol 105 no 2 pp 449ndash453 2007
[32] A Ali M K Ong and C F Forney ldquoEffect of ozone pre-conditioning on quality and antioxidant capacity of papayafruit during ambient storagerdquo Food Chemistry vol 142 no 2pp 19ndash26 2014
[33] X Wang S Gu and B Chen ldquoe mechanism of cholesterol-effect on the quality of green asparagus (Asparagus officinalisL) spears during low temperature storagerdquo Scientia Horti-culturae vol 231 pp 36ndash42 2018
[34] M Sivapriya and S Leela ldquoIsolation and purification of anovel antioxidant protein from the water extract of Sundakai(Solanum torvum) seedsrdquo Food Chemistry vol 104 no 2pp 510ndash517 2007
[35] F V Breusegem E Vranova J F Dat and D Inze ldquoe roleof active oxygen species in plant signal transductionrdquo PlantScience vol 161 no 3 pp 405ndash414 2001
[36] L M Segal and R A Wilson ldquoReactive oxygen speciesmetabolism and plant-fungal interactionsrdquo Fungal Geneticsand Biology vol 110 pp 1ndash9 2018
[37] Y Wang X Xie and L E Long ldquoe effect of postharvestcalcium application in hydro-cooling water on tissue calciumcontent biochemical changes and quality attributes of sweetcherry fruitrdquo Food Chemistry vol 160 no 11 pp 22ndash30 2014
[38] Y Imahori J Bai and E Baldwin ldquoAntioxidative responses ofripe tomato fruit to postharvest chilling and heating treat-mentsrdquo Scientia Horticulturae vol 198 no 75 pp 398ndash4062016
period there was no signicant dierence between theMDAcontent of two groups
343 Superoxide Catalase Peroxidase and Ascorbic Per-oxidase Activities As shown in Figure 8 during the wholestorage period the activities of SOD CAT POD and APXin mango fruits showed a constant increase tendencyPrecooled fruits exhibited higher SOD and CAT activitiesin the entire storage period On the 20th day treated fruitshad 232 higher CAT activity and 27 higher SOD ac-tivity than control fruits respectively (Figures 8(a) and8(b))
Precooling treatment enhanced POD activity in mangofruits except on the 5th day of storage On the 15th and 20thday of storage precooled fruits had 236 and 105 higherPOD activity than control fruits respectively (Figure 8(c))At the beginning of storage precooled fruits showed higherAPX activity which was 1266 higher than the controlWhile at the end of storage precooling treatment had no
signicant incopyuence on APX activity in mango fruits(Figure 8(d))
344 Glutathione Content and Glutathione ReductaseActivity As shown in Figure 9(a) GSH content in mangofruits showed a gradually increase during rst 10 days andthen decreased slowly Precooled fruits had higher GSHcontent than control fruits during the whole storage On the10th and 15th day of storage treated fruits had 221 and127 higher GSH content than control fruits respectively
GR activity in mango fruits increased with the pro-longing of the storage time Precooled fruits had lower GRactivity than control fruits at earlier storage At the end of thestorage the GR activity in precooled fruits was slightlyhigher but the dierence was not signicant (Pgt 005Figure 9(b))
345 Polyphenoloxidase Activity As shown in Figure 10PPO activity in control fruits increased dramatically at
0
2
4
6
8
0 5 10 15 20
Chlo
roph
yll a
cont
ent
(mgmiddot
100g
ndash1middotF
W)
ControlPrecooling
Days of storage
(a)
Chlo
roph
yll a
cont
ent
(mgmiddot
100g
ndash1middotF
W)
ControlPrecooling
00
02
04
06
0 5 10 15 20Days of storage
(b)
Chlo
roph
yll b
cont
ent
(mgmiddot
100g
ndash1middotF
W)
ControlPrecooling
00
05
10
15
20
25
0 5 10 15 20Days of storage
(c)
Chlo
roph
yll b
cont
ent
(mgmiddot
100g
ndash1middotF
W)
ControlPrecooling
00
01
02
0 5 10 15 20Days of storage
(d)
Figure 3 Eects of forced air precooling treatment on chlorophyll a of peel (a) and copyesh (b) and chlorophyll b of mango fruit peel (c) and copyesh(d)
6 Journal of Food Quality
earlier storage and had a peak activity on the 5th day ofstorage after which PPO activity decreased and was keptstable PPO activity in precooled fruits was always at a lowerlevel On the 5th day and 20th day precooled fruits had 819and 674 lower PPO activity than control fruitsrespectively
4 Discussion
Mango fruits are a typical climacteric fruit and commonlyharvested at a green mature stage to prevent the postharvestloss [25] After harvest fruits begin to ripe with the char-acteristic changes on peel coloration textural softeningsugar maintenance suer from over softening and ripeningduring storage which result in postharvest quality de-terioration and short shelf-life [26] In this study the resultsshowed that precooling treatment could retard fruit soft-ening peel coloration accumulation of sugar and organicacid and disease development on mango fruits and all ofwhich were closely related to the maintenance of fruitripening [27]
04
05
06
07
08
09
10
0 5 10 15 20
Flav
onoi
ds co
nten
t (O
D32
5 gndash1
middotFW
)
Days of storage
ControlPrecooling
Figure 5 Eects of forced air precooling treatment on copyavonoidcontent
4
8
12
16
20
0 5 10 15 20
Tota
l sol
uble
solid
s (
)
ControlPrecooling
Days of storage
(a)
0
1
2
0 5 10 15 20
Titr
atab
le ac
idity
cont
ent (
)
ControlPrecooling
Days of storage
(b)
ControlPrecooling
02
03
04
05
06
0 5 10 15 20
Solu
ble s
ugar
cont
ent (
)
Days of storage
(c)
ControlPrecooling
00
02
04
06
08
0 5 10 15 20
Star
ch co
nten
t (
)
Days of storage
(d)
FIGURE 4 Eects of forced air precooling treatment on TSS (a) TA (b) soluble sugar (c) and starch (d) content
Journal of Food Quality 7
Firmness is an important parameter in postharveststorage and marketing Loss of rmness caused by degra-dation of cell wall and starch may result in physical damagesin transportation and fruit susceptibility to pathogen attacks[2] In this study precooled fruits showed higher rmnessduring the entire storage It is in coincidence with previousstudy on waxberry and black mulberry fruits [1] It indicatedthat precooling treatment could retard mango fruitrsquos soft-ening and ripening and it might be related to the decreasedrespiration in the early of storage During postharvest rip-ening the chlorophyll content in mango peel decreased andthe peel color changes from green to yellow [28] Usually thepeel color was considered as an important indicator of fruitmaturity and a critical parameter in fruit marketing [29] Inthis study precooled fruits showed a lower yellow index andblowast value than control fruits and it was closely related to
higher chlorophyll a and chlorophyll b content in mangofruits peel during the storage [13] However the pigment inmango copyesh was not incopyuenced by precooling treatmentFruit weight loss is an important postharvest parameterincopyuencing fruit storage quality shelf-life and economicvalue In the current study however precooling treatmentpromoted fruit weight loss in storage at might be becausethat precooling treatment speeded water transpiration onmango fruitrsquos surface and enhanced fruit water loss Forcedair precooling was done without humidied air leading tohigher weight loss
After harvest mango fruits showed high respiration rateand metabolism activity which accelerated the consumptionof nutritional compounds and fruit ripening With fruitripening SSC and soluble sugar increase because of poly-saccharide hydrolysis while starch a vital polysaccharide in
0
2
4
6
8
10
0 5 10 15 20Days of storage
ControlTreatment
Rate
of O
2ndash pro
duct
ion
(nm
olmiddotg
ndash1middotF
Wmiddotm
inndash1
)
(a)
ControlTreatment
005
010
015
0 5 10 15 20
MD
A co
nten
t (nm
olmiddotg
ndash1middotF
W )
Days of storage
(b)
Figure 7 Eects of forced air precooling treatment on Ominus2 production (a) and MDA content (b)
0
20
40
60
80
100
10 15 20
Dec
ay in
cide
nce (
)
Days of storage
ControlPrecooling
(a)
ControlPrecooling
0
1
2
3
4
10 15 20
Dec
ay se
verit
y (
)
Days of storage
(b)
Figure 6 Eects of forced air precooling treatment on decay incidence (a) and decay severity (b)
8 Journal of Food Quality
fruit decreases continuously [30] In the current studyprecooled fruits showed lower SSC and higher starch contentduring the entire storage It indicated precooling treatmentretarded the hydrolysis of polysaccharides to SSC Mean-while starch degradation is closely related with fruit soft-ening Inhibiting the degradation of starch to SSC alsocontributed to the fruit rmness maintenance [15] econtent of TA represents the concentration of organic acidin fruits Fruit respiration can promote organic acid con-sumption and reduce TA content [31] During storage thecontent of TA in mango fruits decreased rapidly and pre-cooling treatment inhibited the tendency e change ofSSC TA and starch content might be related to the delay inthe ripening process and reduction of respiration rate Incoincidence with the previous study on apricot [10] pre-cooling treatment enhanced copyavonoids content in mangofruits in the late stage of storage Flavonoids content is animportant indicator of fruitrsquos antioxidant capacity [32] and
precooling treatment might contribute to mango fruitsantioxidant capacities However possible mechanisms needto be studied further
With the prolonging of storage fruit resistance topathogen decreases because of ripening and softening anddecay happens e current study found that precoolingtreatment reduced decay on mango fruits including decayincidence and decay index (decay severity) which is similarto the study on green asparagus and broccoli [33] It ispossible because that precooling treatment retarded mangofruit ripening and maintained fruit resistance to postharvestpathogens
Although reactive oxygen species (ROS) was benecial tothe improvement of plant disease resistance excessive ROScan aect DNA replication and protein synthesis resultingin fruit senescence [34] According to free radical theorysenescence was a process of active oxygen metabolismdisorders and accumulation When the fruits are forced by
0
10
20
30
40
0 5 10 15 20
CAT
activ
ity (U
middotgndash1
middotFW
middotmin
ndash1)
ControlTreatment
Days of storage
(a)
ControlTreatment
Days of storage
50
55
60
0 5 10 15 20
SOD
activ
ity (U
middotgndash1
middotFW
)
(b)
ControlTreatment
0
200
400
600
0 5 10 15 20
POD
activ
ity (U
middotgndash1
middotFW
middotmin
ndash1)
Days of storage
(c)
ControlTreatment
0
100
200
300
400
500
0 5 10 15 20
APX
activ
ity (U
middotgndash1
middotFW
middotmin
ndash1)
Days of storage
(d)
Figure 8 Eects of forced air precooling treatment on CAT (a) SOD (b) POD (c) and APX (d) activity
Journal of Food Quality 9
outside stresses reactive oxygen species metabolism balanceis broken free radicals are accumulated in abundance andthe peroxidation of membrane lipid is improved or aggra-vated all of which induce the fruit senescence [13] O2minus is akind of reactive oxygen species with relatively high viru-lence playing an important role in horticultural plant rip-ening and senescence processes particularly in membranedeterioration [35] is study showed that the O2minus pro-duction rate in mango fruits increased rapidly at the end ofstorage leading to senescence of mango Precooling treat-ment inhibited the increase of O2minus production rate andsubsequent fruit senescence Moreover being as the productof membrane lipid peroxidation MDA was usually used toevaluate the degree of membrane damage [36] and lipidperoxidation [37] In this study MDA content was increasedrapidly during the later storage period and was always at ahigher levelis veried that the mango fruitrsquos cellulose was
peroxidated and the integrity of the cell membrane wasdestroyed
ere are many active oxygen removal systems in planttissue e excessive active oxygen was eliminated by dif-ferent antioxidant enzymes [13] O2minus can be transformedinto H2O2 by SOD in the plants is study found thatprecooling treatment enhanced the SOD activity of mangofruits during storage at might be why precooled fruit hadlower O2minus production rate than control fruits In additionwe also found that precooled fruits had higher CAT andPOD activities than control fruits We could include thatprecooled fruits had lower reactive oxygen species thancontrol fruits However there was no signicant dierenceof APX between the precooled fruits and control fruits in thisstudy is could be due to the higher activity of CAT andPOD in mango fruits and APX had not played a major partin elimination of H2O2 erefore the balance betweenSOD POD CAT and APX activities in plants is importantfor determining the steady-state levels of H2O2 and ROS[38]
Glutathione (GSH) is also a very important kind of theactive oxygen removal material [35] In plant tissue GSHcan reduce dehydroascorbic acid (DHA) to ascorbic acid(ASA) and ASA can eliminate H2O2 directly Glutathionereductase (GR) is the key enzyme involved in the GSHgeneration from oxidized glutathione (GSSC) [13 35] isstudy showed that precooled fruits had a higher GSHcontent and GR activity than control fruits during thestorage all of which contributed to the delay of fruit ripeningand senescence
Previous reports indicated that PPO was directly relatedto browning and decay Decrease in its activity would lead toan induced resistance to browning and decay [25] In normalcircumstances PPO usually exists in organelles membraneand cell membrane so the PPO activity is low [13]When thestructure of cell membrane is destroyed PPO is released andthe activity increases In this study the PPO activity in
20
40
60
80
0 5 10 15 20
GSH
cont
ent (
nmol
middotgndash1
middotFW
)
Days of storage
ControlTreatment
(a)
ControlTreatment
0
100
200
300
0 5 10 15 20
GR
activ
ity (U
middotgndash1
middotFW
middotmin
ndash1)
Days of storage
(b)
Figure 9 Eects of forced air precooling treatment on GSH content (a) and GR activity (b)
0
2
4
6
8
10
12
14
0 5 10 15 20
PPO
activ
ity (U
middotgndash1
middotFW
middotmin
ndash1)
Days of storage
ControlTreatment
Figure 10 Eects of forced air precooling treatment on PPOactivity
10 Journal of Food Quality
precooled fruits was always kept in a low level and thismight be because the precooling treatment enhanced theantioxidant defense capabilities and helped to maintain cellintegrity
5 Conclusion
Mango fruitrsquos quality was significantly improved by forcedair precooling treatment Precooling treatment delayed fruitripening and senescence with inhibition of ROS and en-hancement of active oxygen removal enzymes such as su-peroxide dismutase (SOD) catalase (CAT) peroxidase(POD) glutathione reductase (GR) and polyphenoloxidase(PPO) e firmness was maintained and fruit decay wasinhibited during storage ese results indicate that forcedair precooling treatment could maintain mango fruitrsquosquality by enhancing antioxidant activity and delaying fruitripening erefore it is suggested that mango fruits shouldbe precooled immediately after harvest for maintaining fruitquality and prolonging shelf-life
Data Availability
e data used to support the findings of this study areavailable from the corresponding author upon request
Conflicts of Interest
e authors declare that there are no conflicts of interestassociated with the publication of this manuscript
Acknowledgments
is research was supported by Support Project of High-Level Teachers in Beijing Municipal Universities in thePeriod of the 13th Five-Year Plan (CITampTCD201704037)Construction of Scientific Research Innovation ServiceAbility-Basic Scientific Research Operating Expense-FoodFeature Project (PXM2018_014213_000033) and SupportProject of High-Level Teachers in Beijing Municipal Uni-versities (IDHT20180506)
References
[1] Q Han H Gao H Chen X Fang and W Wu ldquoPrecoolingand ozone treatments affects postharvest quality of blackmulberry (Morus nigra) fruitsrdquo Food Chemistry vol 221pp 1947ndash1953 2017
[2] G M Cosme Silva W B Silva D B Medeiros et al ldquoechitosan affects severely the carbon metabolism in mango(Mangifera indica L cv Palmer) fruit during storagerdquo FoodChemistry vol 237 pp 372ndash378 2017
[3] J Li Q Li X J Lei et al ldquoEffects of wax coating on themoisture loss of cucumbers at different storage temperaturesrdquoJournal of food quality vol 2018 no 12 pp 1ndash6 2018
[4] H J Zhou Z W YE M S Su and J H Du ldquoEffects of lowtemperature and forced air precooling on precooling per-formance of different varieties of peach fruitsrdquo Storage ampProcess vol 15 pp 16ndash19 2015
[5] A Rab H Rehman I Haq M Sajid K Nawab and K AlildquoHarvest stages and pre-cooling influence the quality and
storage life of tomato fruitrdquo Journal Animal amp Plant Sciencevol 23 no 5 pp 1347ndash1357 2013
[6] M Zhou K H Ndeurumio L Zhao and Z Hu ldquoImpact ofprecooling and controlled-atmosphere storage on γ--aminobutyric acid (GABA) accumulation in longan (dimo-carpus longan lour) fruitrdquo Journal of Agricultural and FoodChemistry vol 64 no 33 pp 6443ndash6450 2016
[7] D Martinez-Romero S Castillo and D Valero ldquoForced aircooling applied before fruit handling to prevent mechanicaldamage of plums (Prunus salicina Lindl)rdquo Postharvest Biologyamp Technology vol 28 no 1 pp 135ndash142 2003
[8] H Nalbandi S Seiiedlou H R Ghasemzadeh andF Rangbar ldquoInnovative parallel airflow system for forced-aircooling of strawberriesrdquo Food and Bioproducts Processingvol 100 pp 440ndash449 2016
[9] J L OrsquoSullivan M J Ferrua R Love P VerbovenB Nicolaı and A East ldquoForced air cooling of polylinedhorticultural produce optimal cooling conditions andpackage designrdquo Postharvest Biology amp Technology vol 126pp 67ndash75 2017
[10] J Yan Y Song J Li and W Jiang ldquoForced-air precoolingtreatment enhanced antioxidant capacities of apricotsrdquoJournal of Food Processing and Preservation vol 42 no 1article e13320 2018
[11] M Jincy M Djanaguiraman P JeyakumarK S Subramanian S Jayasankar and G Paliyath ldquoInhibitionof phospholipase D enzyme activity through hexanal leads todelayed mango (Mangifera indica L) fruit ripening throughchanges in oxidants and antioxidant enzymes activityrdquo Sci-entia Horticulturae vol 218 pp 316ndash325 2017
[12] J Li G W Ma L Ma et al ldquoMultivariate analysis of fruitantioxidant activities of blackberry treated with 1-Methyl-cyclopropene or vacuum precoolingrdquo International Journal ofAnalytical Chemistry vol 2018 Article ID 2416461 5 pages2018
[13] P Sharma A B Jha R S Dubey andM Pessarakli ldquoReactiveoxygen species oxidative damage and antioxidative defensemechanism in plants under stressful conditionsrdquo Journal ofBotany vol 2012 Article ID 217037 26 pages 2012
[14] O Elloumi M Ghrab andM BenMimoun ldquoEffects of flowerbuds removal on seasonal starch storage and mobilization infruiting and non-fruiting branches of pistachio trees cvMateur under dry and warm climaterdquo Scientia Horticulturaevol 172 no 3 pp 19ndash25 2014
[15] K Liu J Liu H Li C Yuan J Zhong and Y Chen ldquoInfluenceof postharvest citric acid and chitosan coating treatment onripening attributes and expression of cell wall related genes incherimoya (Annona cherimola Mill) fruitrdquo Scientia Horti-culturae vol 198 no 10 pp 1ndash11 2016
[16] D M Hodges J M Delong C F Forney and R K PrangeldquoImproving the thiobarbituric acid-reactive-substances assayfor estimating lipid peroxidation in plant tissues containinganthocyanin and other interfering compoundsrdquo Plantavol 207 no 4 pp 604ndash611 1999
[17] J E Brehe andH B Burch ldquoEnzymatic assay for glutathionerdquoAnalytical Biochemistry vol 74 no 1 pp 189ndash197 1976
[18] D Prochazkova R K Sairam G C Srivastava andD V Singh ldquoOxidative stress and antioxidant activity as thebasis of senescence in maize leavesrdquo Plant Science vol 161no 4 pp 765ndash771 2001
[19] C Larrigaudiere I Lentheric J Puy and E Pinto ldquoBio-chemical characterisation of core browning and brown heartdisorders in pear bymultivariate analysisrdquo Postharvest Biologyand Technology vol 31 no 1 pp 29ndash39 2004
Journal of Food Quality 11
[20] S Naima M R Khan and S Maria ldquoAntioxidant activitytotal phenolic and total flavonoid contents of whole plantextracts Torilis leptophylla Lrdquo BMC Complementary and Al-ternative Medicine vol 12 no 1 p 221 2012
[21] Y Nakano and K Asada ldquoPurification of ascorbate peroxi-dase in spinach chloroplasts its inactivation in ascorbate-depleted medium and reactivation by monodehydroascorbateradicalrdquo Plant amp Cell Physiology vol 28 no 1 pp 131ndash1401987
[22] C H Foyer and B Halliwell ldquoe presence of glutathione andglutathione reductase in chloroplasts a proposed role inascorbic acid metabolismrdquo Planta vol 133 no 1 pp 21ndash251976
[23] F Zhu Z Yun Q Ma et al ldquoEffects of exogenous 24-epi-brassinolide treatment on postharvest quality and resistanceof Satsuma Mandarin (Citrus unshiu)rdquo Postharvest Biologyand Technology vol 100 pp 8ndash15 2015
[24] S Zhu and B Ma ldquoBenzothiadiazole- or methyl jasmonate-induced resistance toColletotrichum musaein harvested ba-nana fruit is related to elevated defense enzyme activitiesrdquolteJournal of Horticultural Science and Biotechnology vol 82no 4 pp 500ndash506 2007
[25] J-W Han J-P Qian C-J Zhao X-T Yang and B-L FanldquoMathematical modelling of cooling efficiency of ventilatedpackaging integral performance evaluationrdquo InternationalJournal of Heat andMass Transfer vol 111 pp 386ndash397 2017
[26] X Zheng L Ye T Jiang G Jing and J Li ldquoLimiting thedeterioration of mango fruit during storage at room tem-perature by oxalate treatmentrdquo Food Chemistry vol 130no 2 pp 279ndash285 2012
[27] J K Dhemre D P Waskar S D Masalkar andR S Gaikwad ldquoEffect of post-harvest treatments on shelf lifeand quality of mango cv Kesar in cool storage and ambientconditionsrdquo Agricultural Science Digest vol 25 no 2pp 79ndash84 2005
[28] M Fleancu ldquoCorrelations among some physiological pro-cesses in apple fruit during growing and maturation pro-cessesrdquo International Journal of Agriculture amp Biologyvol 8530 pp 9ndash4 2007
[29] H Vergara-Domınguez J J Rıos B Gandul-Rojas andM Roca ldquoChlorophyll catabolism in olive fruits (var Arbe-quina and Hojiblanca) during maturationrdquo Food Chemistryvol 212 pp 604ndash611 2016
[30] S S Zaharah and Z Singh ldquoPostharvest nitric oxide fumi-gation alleviates chilling injury delays fruit ripening andmaintains quality in cold-stored ldquoKensington Priderdquo mangordquoPostharvest Biology and Technology vol 60 no 3 pp 202ndash210 2011
[31] M Babalar M Asghari A Talaei and A Khosroshahi ldquoEffectof pre- and postharvest salicylic acid treatment on ethyleneproduction fungal decay and overall quality of Selva strawberryfruitrdquo Food Chemistry vol 105 no 2 pp 449ndash453 2007
[32] A Ali M K Ong and C F Forney ldquoEffect of ozone pre-conditioning on quality and antioxidant capacity of papayafruit during ambient storagerdquo Food Chemistry vol 142 no 2pp 19ndash26 2014
[33] X Wang S Gu and B Chen ldquoe mechanism of cholesterol-effect on the quality of green asparagus (Asparagus officinalisL) spears during low temperature storagerdquo Scientia Horti-culturae vol 231 pp 36ndash42 2018
[34] M Sivapriya and S Leela ldquoIsolation and purification of anovel antioxidant protein from the water extract of Sundakai(Solanum torvum) seedsrdquo Food Chemistry vol 104 no 2pp 510ndash517 2007
[35] F V Breusegem E Vranova J F Dat and D Inze ldquoe roleof active oxygen species in plant signal transductionrdquo PlantScience vol 161 no 3 pp 405ndash414 2001
[36] L M Segal and R A Wilson ldquoReactive oxygen speciesmetabolism and plant-fungal interactionsrdquo Fungal Geneticsand Biology vol 110 pp 1ndash9 2018
[37] Y Wang X Xie and L E Long ldquoe effect of postharvestcalcium application in hydro-cooling water on tissue calciumcontent biochemical changes and quality attributes of sweetcherry fruitrdquo Food Chemistry vol 160 no 11 pp 22ndash30 2014
[38] Y Imahori J Bai and E Baldwin ldquoAntioxidative responses ofripe tomato fruit to postharvest chilling and heating treat-mentsrdquo Scientia Horticulturae vol 198 no 75 pp 398ndash4062016
earlier storage and had a peak activity on the 5th day ofstorage after which PPO activity decreased and was keptstable PPO activity in precooled fruits was always at a lowerlevel On the 5th day and 20th day precooled fruits had 819and 674 lower PPO activity than control fruitsrespectively
4 Discussion
Mango fruits are a typical climacteric fruit and commonlyharvested at a green mature stage to prevent the postharvestloss [25] After harvest fruits begin to ripe with the char-acteristic changes on peel coloration textural softeningsugar maintenance suer from over softening and ripeningduring storage which result in postharvest quality de-terioration and short shelf-life [26] In this study the resultsshowed that precooling treatment could retard fruit soft-ening peel coloration accumulation of sugar and organicacid and disease development on mango fruits and all ofwhich were closely related to the maintenance of fruitripening [27]
04
05
06
07
08
09
10
0 5 10 15 20
Flav
onoi
ds co
nten
t (O
D32
5 gndash1
middotFW
)
Days of storage
ControlPrecooling
Figure 5 Eects of forced air precooling treatment on copyavonoidcontent
4
8
12
16
20
0 5 10 15 20
Tota
l sol
uble
solid
s (
)
ControlPrecooling
Days of storage
(a)
0
1
2
0 5 10 15 20
Titr
atab
le ac
idity
cont
ent (
)
ControlPrecooling
Days of storage
(b)
ControlPrecooling
02
03
04
05
06
0 5 10 15 20
Solu
ble s
ugar
cont
ent (
)
Days of storage
(c)
ControlPrecooling
00
02
04
06
08
0 5 10 15 20
Star
ch co
nten
t (
)
Days of storage
(d)
FIGURE 4 Eects of forced air precooling treatment on TSS (a) TA (b) soluble sugar (c) and starch (d) content
Journal of Food Quality 7
Firmness is an important parameter in postharveststorage and marketing Loss of rmness caused by degra-dation of cell wall and starch may result in physical damagesin transportation and fruit susceptibility to pathogen attacks[2] In this study precooled fruits showed higher rmnessduring the entire storage It is in coincidence with previousstudy on waxberry and black mulberry fruits [1] It indicatedthat precooling treatment could retard mango fruitrsquos soft-ening and ripening and it might be related to the decreasedrespiration in the early of storage During postharvest rip-ening the chlorophyll content in mango peel decreased andthe peel color changes from green to yellow [28] Usually thepeel color was considered as an important indicator of fruitmaturity and a critical parameter in fruit marketing [29] Inthis study precooled fruits showed a lower yellow index andblowast value than control fruits and it was closely related to
higher chlorophyll a and chlorophyll b content in mangofruits peel during the storage [13] However the pigment inmango copyesh was not incopyuenced by precooling treatmentFruit weight loss is an important postharvest parameterincopyuencing fruit storage quality shelf-life and economicvalue In the current study however precooling treatmentpromoted fruit weight loss in storage at might be becausethat precooling treatment speeded water transpiration onmango fruitrsquos surface and enhanced fruit water loss Forcedair precooling was done without humidied air leading tohigher weight loss
After harvest mango fruits showed high respiration rateand metabolism activity which accelerated the consumptionof nutritional compounds and fruit ripening With fruitripening SSC and soluble sugar increase because of poly-saccharide hydrolysis while starch a vital polysaccharide in
0
2
4
6
8
10
0 5 10 15 20Days of storage
ControlTreatment
Rate
of O
2ndash pro
duct
ion
(nm
olmiddotg
ndash1middotF
Wmiddotm
inndash1
)
(a)
ControlTreatment
005
010
015
0 5 10 15 20
MD
A co
nten
t (nm
olmiddotg
ndash1middotF
W )
Days of storage
(b)
Figure 7 Eects of forced air precooling treatment on Ominus2 production (a) and MDA content (b)
0
20
40
60
80
100
10 15 20
Dec
ay in
cide
nce (
)
Days of storage
ControlPrecooling
(a)
ControlPrecooling
0
1
2
3
4
10 15 20
Dec
ay se
verit
y (
)
Days of storage
(b)
Figure 6 Eects of forced air precooling treatment on decay incidence (a) and decay severity (b)
8 Journal of Food Quality
fruit decreases continuously [30] In the current studyprecooled fruits showed lower SSC and higher starch contentduring the entire storage It indicated precooling treatmentretarded the hydrolysis of polysaccharides to SSC Mean-while starch degradation is closely related with fruit soft-ening Inhibiting the degradation of starch to SSC alsocontributed to the fruit rmness maintenance [15] econtent of TA represents the concentration of organic acidin fruits Fruit respiration can promote organic acid con-sumption and reduce TA content [31] During storage thecontent of TA in mango fruits decreased rapidly and pre-cooling treatment inhibited the tendency e change ofSSC TA and starch content might be related to the delay inthe ripening process and reduction of respiration rate Incoincidence with the previous study on apricot [10] pre-cooling treatment enhanced copyavonoids content in mangofruits in the late stage of storage Flavonoids content is animportant indicator of fruitrsquos antioxidant capacity [32] and
precooling treatment might contribute to mango fruitsantioxidant capacities However possible mechanisms needto be studied further
With the prolonging of storage fruit resistance topathogen decreases because of ripening and softening anddecay happens e current study found that precoolingtreatment reduced decay on mango fruits including decayincidence and decay index (decay severity) which is similarto the study on green asparagus and broccoli [33] It ispossible because that precooling treatment retarded mangofruit ripening and maintained fruit resistance to postharvestpathogens
Although reactive oxygen species (ROS) was benecial tothe improvement of plant disease resistance excessive ROScan aect DNA replication and protein synthesis resultingin fruit senescence [34] According to free radical theorysenescence was a process of active oxygen metabolismdisorders and accumulation When the fruits are forced by
0
10
20
30
40
0 5 10 15 20
CAT
activ
ity (U
middotgndash1
middotFW
middotmin
ndash1)
ControlTreatment
Days of storage
(a)
ControlTreatment
Days of storage
50
55
60
0 5 10 15 20
SOD
activ
ity (U
middotgndash1
middotFW
)
(b)
ControlTreatment
0
200
400
600
0 5 10 15 20
POD
activ
ity (U
middotgndash1
middotFW
middotmin
ndash1)
Days of storage
(c)
ControlTreatment
0
100
200
300
400
500
0 5 10 15 20
APX
activ
ity (U
middotgndash1
middotFW
middotmin
ndash1)
Days of storage
(d)
Figure 8 Eects of forced air precooling treatment on CAT (a) SOD (b) POD (c) and APX (d) activity
Journal of Food Quality 9
outside stresses reactive oxygen species metabolism balanceis broken free radicals are accumulated in abundance andthe peroxidation of membrane lipid is improved or aggra-vated all of which induce the fruit senescence [13] O2minus is akind of reactive oxygen species with relatively high viru-lence playing an important role in horticultural plant rip-ening and senescence processes particularly in membranedeterioration [35] is study showed that the O2minus pro-duction rate in mango fruits increased rapidly at the end ofstorage leading to senescence of mango Precooling treat-ment inhibited the increase of O2minus production rate andsubsequent fruit senescence Moreover being as the productof membrane lipid peroxidation MDA was usually used toevaluate the degree of membrane damage [36] and lipidperoxidation [37] In this study MDA content was increasedrapidly during the later storage period and was always at ahigher levelis veried that the mango fruitrsquos cellulose was
peroxidated and the integrity of the cell membrane wasdestroyed
ere are many active oxygen removal systems in planttissue e excessive active oxygen was eliminated by dif-ferent antioxidant enzymes [13] O2minus can be transformedinto H2O2 by SOD in the plants is study found thatprecooling treatment enhanced the SOD activity of mangofruits during storage at might be why precooled fruit hadlower O2minus production rate than control fruits In additionwe also found that precooled fruits had higher CAT andPOD activities than control fruits We could include thatprecooled fruits had lower reactive oxygen species thancontrol fruits However there was no signicant dierenceof APX between the precooled fruits and control fruits in thisstudy is could be due to the higher activity of CAT andPOD in mango fruits and APX had not played a major partin elimination of H2O2 erefore the balance betweenSOD POD CAT and APX activities in plants is importantfor determining the steady-state levels of H2O2 and ROS[38]
Glutathione (GSH) is also a very important kind of theactive oxygen removal material [35] In plant tissue GSHcan reduce dehydroascorbic acid (DHA) to ascorbic acid(ASA) and ASA can eliminate H2O2 directly Glutathionereductase (GR) is the key enzyme involved in the GSHgeneration from oxidized glutathione (GSSC) [13 35] isstudy showed that precooled fruits had a higher GSHcontent and GR activity than control fruits during thestorage all of which contributed to the delay of fruit ripeningand senescence
Previous reports indicated that PPO was directly relatedto browning and decay Decrease in its activity would lead toan induced resistance to browning and decay [25] In normalcircumstances PPO usually exists in organelles membraneand cell membrane so the PPO activity is low [13]When thestructure of cell membrane is destroyed PPO is released andthe activity increases In this study the PPO activity in
20
40
60
80
0 5 10 15 20
GSH
cont
ent (
nmol
middotgndash1
middotFW
)
Days of storage
ControlTreatment
(a)
ControlTreatment
0
100
200
300
0 5 10 15 20
GR
activ
ity (U
middotgndash1
middotFW
middotmin
ndash1)
Days of storage
(b)
Figure 9 Eects of forced air precooling treatment on GSH content (a) and GR activity (b)
0
2
4
6
8
10
12
14
0 5 10 15 20
PPO
activ
ity (U
middotgndash1
middotFW
middotmin
ndash1)
Days of storage
ControlTreatment
Figure 10 Eects of forced air precooling treatment on PPOactivity
10 Journal of Food Quality
precooled fruits was always kept in a low level and thismight be because the precooling treatment enhanced theantioxidant defense capabilities and helped to maintain cellintegrity
5 Conclusion
Mango fruitrsquos quality was significantly improved by forcedair precooling treatment Precooling treatment delayed fruitripening and senescence with inhibition of ROS and en-hancement of active oxygen removal enzymes such as su-peroxide dismutase (SOD) catalase (CAT) peroxidase(POD) glutathione reductase (GR) and polyphenoloxidase(PPO) e firmness was maintained and fruit decay wasinhibited during storage ese results indicate that forcedair precooling treatment could maintain mango fruitrsquosquality by enhancing antioxidant activity and delaying fruitripening erefore it is suggested that mango fruits shouldbe precooled immediately after harvest for maintaining fruitquality and prolonging shelf-life
Data Availability
e data used to support the findings of this study areavailable from the corresponding author upon request
Conflicts of Interest
e authors declare that there are no conflicts of interestassociated with the publication of this manuscript
Acknowledgments
is research was supported by Support Project of High-Level Teachers in Beijing Municipal Universities in thePeriod of the 13th Five-Year Plan (CITampTCD201704037)Construction of Scientific Research Innovation ServiceAbility-Basic Scientific Research Operating Expense-FoodFeature Project (PXM2018_014213_000033) and SupportProject of High-Level Teachers in Beijing Municipal Uni-versities (IDHT20180506)
References
[1] Q Han H Gao H Chen X Fang and W Wu ldquoPrecoolingand ozone treatments affects postharvest quality of blackmulberry (Morus nigra) fruitsrdquo Food Chemistry vol 221pp 1947ndash1953 2017
[2] G M Cosme Silva W B Silva D B Medeiros et al ldquoechitosan affects severely the carbon metabolism in mango(Mangifera indica L cv Palmer) fruit during storagerdquo FoodChemistry vol 237 pp 372ndash378 2017
[3] J Li Q Li X J Lei et al ldquoEffects of wax coating on themoisture loss of cucumbers at different storage temperaturesrdquoJournal of food quality vol 2018 no 12 pp 1ndash6 2018
[4] H J Zhou Z W YE M S Su and J H Du ldquoEffects of lowtemperature and forced air precooling on precooling per-formance of different varieties of peach fruitsrdquo Storage ampProcess vol 15 pp 16ndash19 2015
[5] A Rab H Rehman I Haq M Sajid K Nawab and K AlildquoHarvest stages and pre-cooling influence the quality and
storage life of tomato fruitrdquo Journal Animal amp Plant Sciencevol 23 no 5 pp 1347ndash1357 2013
[6] M Zhou K H Ndeurumio L Zhao and Z Hu ldquoImpact ofprecooling and controlled-atmosphere storage on γ--aminobutyric acid (GABA) accumulation in longan (dimo-carpus longan lour) fruitrdquo Journal of Agricultural and FoodChemistry vol 64 no 33 pp 6443ndash6450 2016
[7] D Martinez-Romero S Castillo and D Valero ldquoForced aircooling applied before fruit handling to prevent mechanicaldamage of plums (Prunus salicina Lindl)rdquo Postharvest Biologyamp Technology vol 28 no 1 pp 135ndash142 2003
[8] H Nalbandi S Seiiedlou H R Ghasemzadeh andF Rangbar ldquoInnovative parallel airflow system for forced-aircooling of strawberriesrdquo Food and Bioproducts Processingvol 100 pp 440ndash449 2016
[9] J L OrsquoSullivan M J Ferrua R Love P VerbovenB Nicolaı and A East ldquoForced air cooling of polylinedhorticultural produce optimal cooling conditions andpackage designrdquo Postharvest Biology amp Technology vol 126pp 67ndash75 2017
[10] J Yan Y Song J Li and W Jiang ldquoForced-air precoolingtreatment enhanced antioxidant capacities of apricotsrdquoJournal of Food Processing and Preservation vol 42 no 1article e13320 2018
[11] M Jincy M Djanaguiraman P JeyakumarK S Subramanian S Jayasankar and G Paliyath ldquoInhibitionof phospholipase D enzyme activity through hexanal leads todelayed mango (Mangifera indica L) fruit ripening throughchanges in oxidants and antioxidant enzymes activityrdquo Sci-entia Horticulturae vol 218 pp 316ndash325 2017
[12] J Li G W Ma L Ma et al ldquoMultivariate analysis of fruitantioxidant activities of blackberry treated with 1-Methyl-cyclopropene or vacuum precoolingrdquo International Journal ofAnalytical Chemistry vol 2018 Article ID 2416461 5 pages2018
[13] P Sharma A B Jha R S Dubey andM Pessarakli ldquoReactiveoxygen species oxidative damage and antioxidative defensemechanism in plants under stressful conditionsrdquo Journal ofBotany vol 2012 Article ID 217037 26 pages 2012
[14] O Elloumi M Ghrab andM BenMimoun ldquoEffects of flowerbuds removal on seasonal starch storage and mobilization infruiting and non-fruiting branches of pistachio trees cvMateur under dry and warm climaterdquo Scientia Horticulturaevol 172 no 3 pp 19ndash25 2014
[15] K Liu J Liu H Li C Yuan J Zhong and Y Chen ldquoInfluenceof postharvest citric acid and chitosan coating treatment onripening attributes and expression of cell wall related genes incherimoya (Annona cherimola Mill) fruitrdquo Scientia Horti-culturae vol 198 no 10 pp 1ndash11 2016
[16] D M Hodges J M Delong C F Forney and R K PrangeldquoImproving the thiobarbituric acid-reactive-substances assayfor estimating lipid peroxidation in plant tissues containinganthocyanin and other interfering compoundsrdquo Plantavol 207 no 4 pp 604ndash611 1999
[17] J E Brehe andH B Burch ldquoEnzymatic assay for glutathionerdquoAnalytical Biochemistry vol 74 no 1 pp 189ndash197 1976
[18] D Prochazkova R K Sairam G C Srivastava andD V Singh ldquoOxidative stress and antioxidant activity as thebasis of senescence in maize leavesrdquo Plant Science vol 161no 4 pp 765ndash771 2001
[19] C Larrigaudiere I Lentheric J Puy and E Pinto ldquoBio-chemical characterisation of core browning and brown heartdisorders in pear bymultivariate analysisrdquo Postharvest Biologyand Technology vol 31 no 1 pp 29ndash39 2004
Journal of Food Quality 11
[20] S Naima M R Khan and S Maria ldquoAntioxidant activitytotal phenolic and total flavonoid contents of whole plantextracts Torilis leptophylla Lrdquo BMC Complementary and Al-ternative Medicine vol 12 no 1 p 221 2012
[21] Y Nakano and K Asada ldquoPurification of ascorbate peroxi-dase in spinach chloroplasts its inactivation in ascorbate-depleted medium and reactivation by monodehydroascorbateradicalrdquo Plant amp Cell Physiology vol 28 no 1 pp 131ndash1401987
[22] C H Foyer and B Halliwell ldquoe presence of glutathione andglutathione reductase in chloroplasts a proposed role inascorbic acid metabolismrdquo Planta vol 133 no 1 pp 21ndash251976
[23] F Zhu Z Yun Q Ma et al ldquoEffects of exogenous 24-epi-brassinolide treatment on postharvest quality and resistanceof Satsuma Mandarin (Citrus unshiu)rdquo Postharvest Biologyand Technology vol 100 pp 8ndash15 2015
[24] S Zhu and B Ma ldquoBenzothiadiazole- or methyl jasmonate-induced resistance toColletotrichum musaein harvested ba-nana fruit is related to elevated defense enzyme activitiesrdquolteJournal of Horticultural Science and Biotechnology vol 82no 4 pp 500ndash506 2007
[25] J-W Han J-P Qian C-J Zhao X-T Yang and B-L FanldquoMathematical modelling of cooling efficiency of ventilatedpackaging integral performance evaluationrdquo InternationalJournal of Heat andMass Transfer vol 111 pp 386ndash397 2017
[26] X Zheng L Ye T Jiang G Jing and J Li ldquoLimiting thedeterioration of mango fruit during storage at room tem-perature by oxalate treatmentrdquo Food Chemistry vol 130no 2 pp 279ndash285 2012
[27] J K Dhemre D P Waskar S D Masalkar andR S Gaikwad ldquoEffect of post-harvest treatments on shelf lifeand quality of mango cv Kesar in cool storage and ambientconditionsrdquo Agricultural Science Digest vol 25 no 2pp 79ndash84 2005
[28] M Fleancu ldquoCorrelations among some physiological pro-cesses in apple fruit during growing and maturation pro-cessesrdquo International Journal of Agriculture amp Biologyvol 8530 pp 9ndash4 2007
[29] H Vergara-Domınguez J J Rıos B Gandul-Rojas andM Roca ldquoChlorophyll catabolism in olive fruits (var Arbe-quina and Hojiblanca) during maturationrdquo Food Chemistryvol 212 pp 604ndash611 2016
[30] S S Zaharah and Z Singh ldquoPostharvest nitric oxide fumi-gation alleviates chilling injury delays fruit ripening andmaintains quality in cold-stored ldquoKensington Priderdquo mangordquoPostharvest Biology and Technology vol 60 no 3 pp 202ndash210 2011
[31] M Babalar M Asghari A Talaei and A Khosroshahi ldquoEffectof pre- and postharvest salicylic acid treatment on ethyleneproduction fungal decay and overall quality of Selva strawberryfruitrdquo Food Chemistry vol 105 no 2 pp 449ndash453 2007
[32] A Ali M K Ong and C F Forney ldquoEffect of ozone pre-conditioning on quality and antioxidant capacity of papayafruit during ambient storagerdquo Food Chemistry vol 142 no 2pp 19ndash26 2014
[33] X Wang S Gu and B Chen ldquoe mechanism of cholesterol-effect on the quality of green asparagus (Asparagus officinalisL) spears during low temperature storagerdquo Scientia Horti-culturae vol 231 pp 36ndash42 2018
[34] M Sivapriya and S Leela ldquoIsolation and purification of anovel antioxidant protein from the water extract of Sundakai(Solanum torvum) seedsrdquo Food Chemistry vol 104 no 2pp 510ndash517 2007
[35] F V Breusegem E Vranova J F Dat and D Inze ldquoe roleof active oxygen species in plant signal transductionrdquo PlantScience vol 161 no 3 pp 405ndash414 2001
[36] L M Segal and R A Wilson ldquoReactive oxygen speciesmetabolism and plant-fungal interactionsrdquo Fungal Geneticsand Biology vol 110 pp 1ndash9 2018
[37] Y Wang X Xie and L E Long ldquoe effect of postharvestcalcium application in hydro-cooling water on tissue calciumcontent biochemical changes and quality attributes of sweetcherry fruitrdquo Food Chemistry vol 160 no 11 pp 22ndash30 2014
[38] Y Imahori J Bai and E Baldwin ldquoAntioxidative responses ofripe tomato fruit to postharvest chilling and heating treat-mentsrdquo Scientia Horticulturae vol 198 no 75 pp 398ndash4062016
Firmness is an important parameter in postharveststorage and marketing Loss of rmness caused by degra-dation of cell wall and starch may result in physical damagesin transportation and fruit susceptibility to pathogen attacks[2] In this study precooled fruits showed higher rmnessduring the entire storage It is in coincidence with previousstudy on waxberry and black mulberry fruits [1] It indicatedthat precooling treatment could retard mango fruitrsquos soft-ening and ripening and it might be related to the decreasedrespiration in the early of storage During postharvest rip-ening the chlorophyll content in mango peel decreased andthe peel color changes from green to yellow [28] Usually thepeel color was considered as an important indicator of fruitmaturity and a critical parameter in fruit marketing [29] Inthis study precooled fruits showed a lower yellow index andblowast value than control fruits and it was closely related to
higher chlorophyll a and chlorophyll b content in mangofruits peel during the storage [13] However the pigment inmango copyesh was not incopyuenced by precooling treatmentFruit weight loss is an important postharvest parameterincopyuencing fruit storage quality shelf-life and economicvalue In the current study however precooling treatmentpromoted fruit weight loss in storage at might be becausethat precooling treatment speeded water transpiration onmango fruitrsquos surface and enhanced fruit water loss Forcedair precooling was done without humidied air leading tohigher weight loss
After harvest mango fruits showed high respiration rateand metabolism activity which accelerated the consumptionof nutritional compounds and fruit ripening With fruitripening SSC and soluble sugar increase because of poly-saccharide hydrolysis while starch a vital polysaccharide in
0
2
4
6
8
10
0 5 10 15 20Days of storage
ControlTreatment
Rate
of O
2ndash pro
duct
ion
(nm
olmiddotg
ndash1middotF
Wmiddotm
inndash1
)
(a)
ControlTreatment
005
010
015
0 5 10 15 20
MD
A co
nten
t (nm
olmiddotg
ndash1middotF
W )
Days of storage
(b)
Figure 7 Eects of forced air precooling treatment on Ominus2 production (a) and MDA content (b)
0
20
40
60
80
100
10 15 20
Dec
ay in
cide
nce (
)
Days of storage
ControlPrecooling
(a)
ControlPrecooling
0
1
2
3
4
10 15 20
Dec
ay se
verit
y (
)
Days of storage
(b)
Figure 6 Eects of forced air precooling treatment on decay incidence (a) and decay severity (b)
8 Journal of Food Quality
fruit decreases continuously [30] In the current studyprecooled fruits showed lower SSC and higher starch contentduring the entire storage It indicated precooling treatmentretarded the hydrolysis of polysaccharides to SSC Mean-while starch degradation is closely related with fruit soft-ening Inhibiting the degradation of starch to SSC alsocontributed to the fruit rmness maintenance [15] econtent of TA represents the concentration of organic acidin fruits Fruit respiration can promote organic acid con-sumption and reduce TA content [31] During storage thecontent of TA in mango fruits decreased rapidly and pre-cooling treatment inhibited the tendency e change ofSSC TA and starch content might be related to the delay inthe ripening process and reduction of respiration rate Incoincidence with the previous study on apricot [10] pre-cooling treatment enhanced copyavonoids content in mangofruits in the late stage of storage Flavonoids content is animportant indicator of fruitrsquos antioxidant capacity [32] and
precooling treatment might contribute to mango fruitsantioxidant capacities However possible mechanisms needto be studied further
With the prolonging of storage fruit resistance topathogen decreases because of ripening and softening anddecay happens e current study found that precoolingtreatment reduced decay on mango fruits including decayincidence and decay index (decay severity) which is similarto the study on green asparagus and broccoli [33] It ispossible because that precooling treatment retarded mangofruit ripening and maintained fruit resistance to postharvestpathogens
Although reactive oxygen species (ROS) was benecial tothe improvement of plant disease resistance excessive ROScan aect DNA replication and protein synthesis resultingin fruit senescence [34] According to free radical theorysenescence was a process of active oxygen metabolismdisorders and accumulation When the fruits are forced by
0
10
20
30
40
0 5 10 15 20
CAT
activ
ity (U
middotgndash1
middotFW
middotmin
ndash1)
ControlTreatment
Days of storage
(a)
ControlTreatment
Days of storage
50
55
60
0 5 10 15 20
SOD
activ
ity (U
middotgndash1
middotFW
)
(b)
ControlTreatment
0
200
400
600
0 5 10 15 20
POD
activ
ity (U
middotgndash1
middotFW
middotmin
ndash1)
Days of storage
(c)
ControlTreatment
0
100
200
300
400
500
0 5 10 15 20
APX
activ
ity (U
middotgndash1
middotFW
middotmin
ndash1)
Days of storage
(d)
Figure 8 Eects of forced air precooling treatment on CAT (a) SOD (b) POD (c) and APX (d) activity
Journal of Food Quality 9
outside stresses reactive oxygen species metabolism balanceis broken free radicals are accumulated in abundance andthe peroxidation of membrane lipid is improved or aggra-vated all of which induce the fruit senescence [13] O2minus is akind of reactive oxygen species with relatively high viru-lence playing an important role in horticultural plant rip-ening and senescence processes particularly in membranedeterioration [35] is study showed that the O2minus pro-duction rate in mango fruits increased rapidly at the end ofstorage leading to senescence of mango Precooling treat-ment inhibited the increase of O2minus production rate andsubsequent fruit senescence Moreover being as the productof membrane lipid peroxidation MDA was usually used toevaluate the degree of membrane damage [36] and lipidperoxidation [37] In this study MDA content was increasedrapidly during the later storage period and was always at ahigher levelis veried that the mango fruitrsquos cellulose was
peroxidated and the integrity of the cell membrane wasdestroyed
ere are many active oxygen removal systems in planttissue e excessive active oxygen was eliminated by dif-ferent antioxidant enzymes [13] O2minus can be transformedinto H2O2 by SOD in the plants is study found thatprecooling treatment enhanced the SOD activity of mangofruits during storage at might be why precooled fruit hadlower O2minus production rate than control fruits In additionwe also found that precooled fruits had higher CAT andPOD activities than control fruits We could include thatprecooled fruits had lower reactive oxygen species thancontrol fruits However there was no signicant dierenceof APX between the precooled fruits and control fruits in thisstudy is could be due to the higher activity of CAT andPOD in mango fruits and APX had not played a major partin elimination of H2O2 erefore the balance betweenSOD POD CAT and APX activities in plants is importantfor determining the steady-state levels of H2O2 and ROS[38]
Glutathione (GSH) is also a very important kind of theactive oxygen removal material [35] In plant tissue GSHcan reduce dehydroascorbic acid (DHA) to ascorbic acid(ASA) and ASA can eliminate H2O2 directly Glutathionereductase (GR) is the key enzyme involved in the GSHgeneration from oxidized glutathione (GSSC) [13 35] isstudy showed that precooled fruits had a higher GSHcontent and GR activity than control fruits during thestorage all of which contributed to the delay of fruit ripeningand senescence
Previous reports indicated that PPO was directly relatedto browning and decay Decrease in its activity would lead toan induced resistance to browning and decay [25] In normalcircumstances PPO usually exists in organelles membraneand cell membrane so the PPO activity is low [13]When thestructure of cell membrane is destroyed PPO is released andthe activity increases In this study the PPO activity in
20
40
60
80
0 5 10 15 20
GSH
cont
ent (
nmol
middotgndash1
middotFW
)
Days of storage
ControlTreatment
(a)
ControlTreatment
0
100
200
300
0 5 10 15 20
GR
activ
ity (U
middotgndash1
middotFW
middotmin
ndash1)
Days of storage
(b)
Figure 9 Eects of forced air precooling treatment on GSH content (a) and GR activity (b)
0
2
4
6
8
10
12
14
0 5 10 15 20
PPO
activ
ity (U
middotgndash1
middotFW
middotmin
ndash1)
Days of storage
ControlTreatment
Figure 10 Eects of forced air precooling treatment on PPOactivity
10 Journal of Food Quality
precooled fruits was always kept in a low level and thismight be because the precooling treatment enhanced theantioxidant defense capabilities and helped to maintain cellintegrity
5 Conclusion
Mango fruitrsquos quality was significantly improved by forcedair precooling treatment Precooling treatment delayed fruitripening and senescence with inhibition of ROS and en-hancement of active oxygen removal enzymes such as su-peroxide dismutase (SOD) catalase (CAT) peroxidase(POD) glutathione reductase (GR) and polyphenoloxidase(PPO) e firmness was maintained and fruit decay wasinhibited during storage ese results indicate that forcedair precooling treatment could maintain mango fruitrsquosquality by enhancing antioxidant activity and delaying fruitripening erefore it is suggested that mango fruits shouldbe precooled immediately after harvest for maintaining fruitquality and prolonging shelf-life
Data Availability
e data used to support the findings of this study areavailable from the corresponding author upon request
Conflicts of Interest
e authors declare that there are no conflicts of interestassociated with the publication of this manuscript
Acknowledgments
is research was supported by Support Project of High-Level Teachers in Beijing Municipal Universities in thePeriod of the 13th Five-Year Plan (CITampTCD201704037)Construction of Scientific Research Innovation ServiceAbility-Basic Scientific Research Operating Expense-FoodFeature Project (PXM2018_014213_000033) and SupportProject of High-Level Teachers in Beijing Municipal Uni-versities (IDHT20180506)
References
[1] Q Han H Gao H Chen X Fang and W Wu ldquoPrecoolingand ozone treatments affects postharvest quality of blackmulberry (Morus nigra) fruitsrdquo Food Chemistry vol 221pp 1947ndash1953 2017
[2] G M Cosme Silva W B Silva D B Medeiros et al ldquoechitosan affects severely the carbon metabolism in mango(Mangifera indica L cv Palmer) fruit during storagerdquo FoodChemistry vol 237 pp 372ndash378 2017
[3] J Li Q Li X J Lei et al ldquoEffects of wax coating on themoisture loss of cucumbers at different storage temperaturesrdquoJournal of food quality vol 2018 no 12 pp 1ndash6 2018
[4] H J Zhou Z W YE M S Su and J H Du ldquoEffects of lowtemperature and forced air precooling on precooling per-formance of different varieties of peach fruitsrdquo Storage ampProcess vol 15 pp 16ndash19 2015
[5] A Rab H Rehman I Haq M Sajid K Nawab and K AlildquoHarvest stages and pre-cooling influence the quality and
storage life of tomato fruitrdquo Journal Animal amp Plant Sciencevol 23 no 5 pp 1347ndash1357 2013
[6] M Zhou K H Ndeurumio L Zhao and Z Hu ldquoImpact ofprecooling and controlled-atmosphere storage on γ--aminobutyric acid (GABA) accumulation in longan (dimo-carpus longan lour) fruitrdquo Journal of Agricultural and FoodChemistry vol 64 no 33 pp 6443ndash6450 2016
[7] D Martinez-Romero S Castillo and D Valero ldquoForced aircooling applied before fruit handling to prevent mechanicaldamage of plums (Prunus salicina Lindl)rdquo Postharvest Biologyamp Technology vol 28 no 1 pp 135ndash142 2003
[8] H Nalbandi S Seiiedlou H R Ghasemzadeh andF Rangbar ldquoInnovative parallel airflow system for forced-aircooling of strawberriesrdquo Food and Bioproducts Processingvol 100 pp 440ndash449 2016
[9] J L OrsquoSullivan M J Ferrua R Love P VerbovenB Nicolaı and A East ldquoForced air cooling of polylinedhorticultural produce optimal cooling conditions andpackage designrdquo Postharvest Biology amp Technology vol 126pp 67ndash75 2017
[10] J Yan Y Song J Li and W Jiang ldquoForced-air precoolingtreatment enhanced antioxidant capacities of apricotsrdquoJournal of Food Processing and Preservation vol 42 no 1article e13320 2018
[11] M Jincy M Djanaguiraman P JeyakumarK S Subramanian S Jayasankar and G Paliyath ldquoInhibitionof phospholipase D enzyme activity through hexanal leads todelayed mango (Mangifera indica L) fruit ripening throughchanges in oxidants and antioxidant enzymes activityrdquo Sci-entia Horticulturae vol 218 pp 316ndash325 2017
[12] J Li G W Ma L Ma et al ldquoMultivariate analysis of fruitantioxidant activities of blackberry treated with 1-Methyl-cyclopropene or vacuum precoolingrdquo International Journal ofAnalytical Chemistry vol 2018 Article ID 2416461 5 pages2018
[13] P Sharma A B Jha R S Dubey andM Pessarakli ldquoReactiveoxygen species oxidative damage and antioxidative defensemechanism in plants under stressful conditionsrdquo Journal ofBotany vol 2012 Article ID 217037 26 pages 2012
[14] O Elloumi M Ghrab andM BenMimoun ldquoEffects of flowerbuds removal on seasonal starch storage and mobilization infruiting and non-fruiting branches of pistachio trees cvMateur under dry and warm climaterdquo Scientia Horticulturaevol 172 no 3 pp 19ndash25 2014
[15] K Liu J Liu H Li C Yuan J Zhong and Y Chen ldquoInfluenceof postharvest citric acid and chitosan coating treatment onripening attributes and expression of cell wall related genes incherimoya (Annona cherimola Mill) fruitrdquo Scientia Horti-culturae vol 198 no 10 pp 1ndash11 2016
[16] D M Hodges J M Delong C F Forney and R K PrangeldquoImproving the thiobarbituric acid-reactive-substances assayfor estimating lipid peroxidation in plant tissues containinganthocyanin and other interfering compoundsrdquo Plantavol 207 no 4 pp 604ndash611 1999
[17] J E Brehe andH B Burch ldquoEnzymatic assay for glutathionerdquoAnalytical Biochemistry vol 74 no 1 pp 189ndash197 1976
[18] D Prochazkova R K Sairam G C Srivastava andD V Singh ldquoOxidative stress and antioxidant activity as thebasis of senescence in maize leavesrdquo Plant Science vol 161no 4 pp 765ndash771 2001
[19] C Larrigaudiere I Lentheric J Puy and E Pinto ldquoBio-chemical characterisation of core browning and brown heartdisorders in pear bymultivariate analysisrdquo Postharvest Biologyand Technology vol 31 no 1 pp 29ndash39 2004
Journal of Food Quality 11
[20] S Naima M R Khan and S Maria ldquoAntioxidant activitytotal phenolic and total flavonoid contents of whole plantextracts Torilis leptophylla Lrdquo BMC Complementary and Al-ternative Medicine vol 12 no 1 p 221 2012
[21] Y Nakano and K Asada ldquoPurification of ascorbate peroxi-dase in spinach chloroplasts its inactivation in ascorbate-depleted medium and reactivation by monodehydroascorbateradicalrdquo Plant amp Cell Physiology vol 28 no 1 pp 131ndash1401987
[22] C H Foyer and B Halliwell ldquoe presence of glutathione andglutathione reductase in chloroplasts a proposed role inascorbic acid metabolismrdquo Planta vol 133 no 1 pp 21ndash251976
[23] F Zhu Z Yun Q Ma et al ldquoEffects of exogenous 24-epi-brassinolide treatment on postharvest quality and resistanceof Satsuma Mandarin (Citrus unshiu)rdquo Postharvest Biologyand Technology vol 100 pp 8ndash15 2015
[24] S Zhu and B Ma ldquoBenzothiadiazole- or methyl jasmonate-induced resistance toColletotrichum musaein harvested ba-nana fruit is related to elevated defense enzyme activitiesrdquolteJournal of Horticultural Science and Biotechnology vol 82no 4 pp 500ndash506 2007
[25] J-W Han J-P Qian C-J Zhao X-T Yang and B-L FanldquoMathematical modelling of cooling efficiency of ventilatedpackaging integral performance evaluationrdquo InternationalJournal of Heat andMass Transfer vol 111 pp 386ndash397 2017
[26] X Zheng L Ye T Jiang G Jing and J Li ldquoLimiting thedeterioration of mango fruit during storage at room tem-perature by oxalate treatmentrdquo Food Chemistry vol 130no 2 pp 279ndash285 2012
[27] J K Dhemre D P Waskar S D Masalkar andR S Gaikwad ldquoEffect of post-harvest treatments on shelf lifeand quality of mango cv Kesar in cool storage and ambientconditionsrdquo Agricultural Science Digest vol 25 no 2pp 79ndash84 2005
[28] M Fleancu ldquoCorrelations among some physiological pro-cesses in apple fruit during growing and maturation pro-cessesrdquo International Journal of Agriculture amp Biologyvol 8530 pp 9ndash4 2007
[29] H Vergara-Domınguez J J Rıos B Gandul-Rojas andM Roca ldquoChlorophyll catabolism in olive fruits (var Arbe-quina and Hojiblanca) during maturationrdquo Food Chemistryvol 212 pp 604ndash611 2016
[30] S S Zaharah and Z Singh ldquoPostharvest nitric oxide fumi-gation alleviates chilling injury delays fruit ripening andmaintains quality in cold-stored ldquoKensington Priderdquo mangordquoPostharvest Biology and Technology vol 60 no 3 pp 202ndash210 2011
[31] M Babalar M Asghari A Talaei and A Khosroshahi ldquoEffectof pre- and postharvest salicylic acid treatment on ethyleneproduction fungal decay and overall quality of Selva strawberryfruitrdquo Food Chemistry vol 105 no 2 pp 449ndash453 2007
[32] A Ali M K Ong and C F Forney ldquoEffect of ozone pre-conditioning on quality and antioxidant capacity of papayafruit during ambient storagerdquo Food Chemistry vol 142 no 2pp 19ndash26 2014
[33] X Wang S Gu and B Chen ldquoe mechanism of cholesterol-effect on the quality of green asparagus (Asparagus officinalisL) spears during low temperature storagerdquo Scientia Horti-culturae vol 231 pp 36ndash42 2018
[34] M Sivapriya and S Leela ldquoIsolation and purification of anovel antioxidant protein from the water extract of Sundakai(Solanum torvum) seedsrdquo Food Chemistry vol 104 no 2pp 510ndash517 2007
[35] F V Breusegem E Vranova J F Dat and D Inze ldquoe roleof active oxygen species in plant signal transductionrdquo PlantScience vol 161 no 3 pp 405ndash414 2001
[36] L M Segal and R A Wilson ldquoReactive oxygen speciesmetabolism and plant-fungal interactionsrdquo Fungal Geneticsand Biology vol 110 pp 1ndash9 2018
[37] Y Wang X Xie and L E Long ldquoe effect of postharvestcalcium application in hydro-cooling water on tissue calciumcontent biochemical changes and quality attributes of sweetcherry fruitrdquo Food Chemistry vol 160 no 11 pp 22ndash30 2014
[38] Y Imahori J Bai and E Baldwin ldquoAntioxidative responses ofripe tomato fruit to postharvest chilling and heating treat-mentsrdquo Scientia Horticulturae vol 198 no 75 pp 398ndash4062016
fruit decreases continuously [30] In the current studyprecooled fruits showed lower SSC and higher starch contentduring the entire storage It indicated precooling treatmentretarded the hydrolysis of polysaccharides to SSC Mean-while starch degradation is closely related with fruit soft-ening Inhibiting the degradation of starch to SSC alsocontributed to the fruit rmness maintenance [15] econtent of TA represents the concentration of organic acidin fruits Fruit respiration can promote organic acid con-sumption and reduce TA content [31] During storage thecontent of TA in mango fruits decreased rapidly and pre-cooling treatment inhibited the tendency e change ofSSC TA and starch content might be related to the delay inthe ripening process and reduction of respiration rate Incoincidence with the previous study on apricot [10] pre-cooling treatment enhanced copyavonoids content in mangofruits in the late stage of storage Flavonoids content is animportant indicator of fruitrsquos antioxidant capacity [32] and
precooling treatment might contribute to mango fruitsantioxidant capacities However possible mechanisms needto be studied further
With the prolonging of storage fruit resistance topathogen decreases because of ripening and softening anddecay happens e current study found that precoolingtreatment reduced decay on mango fruits including decayincidence and decay index (decay severity) which is similarto the study on green asparagus and broccoli [33] It ispossible because that precooling treatment retarded mangofruit ripening and maintained fruit resistance to postharvestpathogens
Although reactive oxygen species (ROS) was benecial tothe improvement of plant disease resistance excessive ROScan aect DNA replication and protein synthesis resultingin fruit senescence [34] According to free radical theorysenescence was a process of active oxygen metabolismdisorders and accumulation When the fruits are forced by
0
10
20
30
40
0 5 10 15 20
CAT
activ
ity (U
middotgndash1
middotFW
middotmin
ndash1)
ControlTreatment
Days of storage
(a)
ControlTreatment
Days of storage
50
55
60
0 5 10 15 20
SOD
activ
ity (U
middotgndash1
middotFW
)
(b)
ControlTreatment
0
200
400
600
0 5 10 15 20
POD
activ
ity (U
middotgndash1
middotFW
middotmin
ndash1)
Days of storage
(c)
ControlTreatment
0
100
200
300
400
500
0 5 10 15 20
APX
activ
ity (U
middotgndash1
middotFW
middotmin
ndash1)
Days of storage
(d)
Figure 8 Eects of forced air precooling treatment on CAT (a) SOD (b) POD (c) and APX (d) activity
Journal of Food Quality 9
outside stresses reactive oxygen species metabolism balanceis broken free radicals are accumulated in abundance andthe peroxidation of membrane lipid is improved or aggra-vated all of which induce the fruit senescence [13] O2minus is akind of reactive oxygen species with relatively high viru-lence playing an important role in horticultural plant rip-ening and senescence processes particularly in membranedeterioration [35] is study showed that the O2minus pro-duction rate in mango fruits increased rapidly at the end ofstorage leading to senescence of mango Precooling treat-ment inhibited the increase of O2minus production rate andsubsequent fruit senescence Moreover being as the productof membrane lipid peroxidation MDA was usually used toevaluate the degree of membrane damage [36] and lipidperoxidation [37] In this study MDA content was increasedrapidly during the later storage period and was always at ahigher levelis veried that the mango fruitrsquos cellulose was
peroxidated and the integrity of the cell membrane wasdestroyed
ere are many active oxygen removal systems in planttissue e excessive active oxygen was eliminated by dif-ferent antioxidant enzymes [13] O2minus can be transformedinto H2O2 by SOD in the plants is study found thatprecooling treatment enhanced the SOD activity of mangofruits during storage at might be why precooled fruit hadlower O2minus production rate than control fruits In additionwe also found that precooled fruits had higher CAT andPOD activities than control fruits We could include thatprecooled fruits had lower reactive oxygen species thancontrol fruits However there was no signicant dierenceof APX between the precooled fruits and control fruits in thisstudy is could be due to the higher activity of CAT andPOD in mango fruits and APX had not played a major partin elimination of H2O2 erefore the balance betweenSOD POD CAT and APX activities in plants is importantfor determining the steady-state levels of H2O2 and ROS[38]
Glutathione (GSH) is also a very important kind of theactive oxygen removal material [35] In plant tissue GSHcan reduce dehydroascorbic acid (DHA) to ascorbic acid(ASA) and ASA can eliminate H2O2 directly Glutathionereductase (GR) is the key enzyme involved in the GSHgeneration from oxidized glutathione (GSSC) [13 35] isstudy showed that precooled fruits had a higher GSHcontent and GR activity than control fruits during thestorage all of which contributed to the delay of fruit ripeningand senescence
Previous reports indicated that PPO was directly relatedto browning and decay Decrease in its activity would lead toan induced resistance to browning and decay [25] In normalcircumstances PPO usually exists in organelles membraneand cell membrane so the PPO activity is low [13]When thestructure of cell membrane is destroyed PPO is released andthe activity increases In this study the PPO activity in
20
40
60
80
0 5 10 15 20
GSH
cont
ent (
nmol
middotgndash1
middotFW
)
Days of storage
ControlTreatment
(a)
ControlTreatment
0
100
200
300
0 5 10 15 20
GR
activ
ity (U
middotgndash1
middotFW
middotmin
ndash1)
Days of storage
(b)
Figure 9 Eects of forced air precooling treatment on GSH content (a) and GR activity (b)
0
2
4
6
8
10
12
14
0 5 10 15 20
PPO
activ
ity (U
middotgndash1
middotFW
middotmin
ndash1)
Days of storage
ControlTreatment
Figure 10 Eects of forced air precooling treatment on PPOactivity
10 Journal of Food Quality
precooled fruits was always kept in a low level and thismight be because the precooling treatment enhanced theantioxidant defense capabilities and helped to maintain cellintegrity
5 Conclusion
Mango fruitrsquos quality was significantly improved by forcedair precooling treatment Precooling treatment delayed fruitripening and senescence with inhibition of ROS and en-hancement of active oxygen removal enzymes such as su-peroxide dismutase (SOD) catalase (CAT) peroxidase(POD) glutathione reductase (GR) and polyphenoloxidase(PPO) e firmness was maintained and fruit decay wasinhibited during storage ese results indicate that forcedair precooling treatment could maintain mango fruitrsquosquality by enhancing antioxidant activity and delaying fruitripening erefore it is suggested that mango fruits shouldbe precooled immediately after harvest for maintaining fruitquality and prolonging shelf-life
Data Availability
e data used to support the findings of this study areavailable from the corresponding author upon request
Conflicts of Interest
e authors declare that there are no conflicts of interestassociated with the publication of this manuscript
Acknowledgments
is research was supported by Support Project of High-Level Teachers in Beijing Municipal Universities in thePeriod of the 13th Five-Year Plan (CITampTCD201704037)Construction of Scientific Research Innovation ServiceAbility-Basic Scientific Research Operating Expense-FoodFeature Project (PXM2018_014213_000033) and SupportProject of High-Level Teachers in Beijing Municipal Uni-versities (IDHT20180506)
References
[1] Q Han H Gao H Chen X Fang and W Wu ldquoPrecoolingand ozone treatments affects postharvest quality of blackmulberry (Morus nigra) fruitsrdquo Food Chemistry vol 221pp 1947ndash1953 2017
[2] G M Cosme Silva W B Silva D B Medeiros et al ldquoechitosan affects severely the carbon metabolism in mango(Mangifera indica L cv Palmer) fruit during storagerdquo FoodChemistry vol 237 pp 372ndash378 2017
[3] J Li Q Li X J Lei et al ldquoEffects of wax coating on themoisture loss of cucumbers at different storage temperaturesrdquoJournal of food quality vol 2018 no 12 pp 1ndash6 2018
[4] H J Zhou Z W YE M S Su and J H Du ldquoEffects of lowtemperature and forced air precooling on precooling per-formance of different varieties of peach fruitsrdquo Storage ampProcess vol 15 pp 16ndash19 2015
[5] A Rab H Rehman I Haq M Sajid K Nawab and K AlildquoHarvest stages and pre-cooling influence the quality and
storage life of tomato fruitrdquo Journal Animal amp Plant Sciencevol 23 no 5 pp 1347ndash1357 2013
[6] M Zhou K H Ndeurumio L Zhao and Z Hu ldquoImpact ofprecooling and controlled-atmosphere storage on γ--aminobutyric acid (GABA) accumulation in longan (dimo-carpus longan lour) fruitrdquo Journal of Agricultural and FoodChemistry vol 64 no 33 pp 6443ndash6450 2016
[7] D Martinez-Romero S Castillo and D Valero ldquoForced aircooling applied before fruit handling to prevent mechanicaldamage of plums (Prunus salicina Lindl)rdquo Postharvest Biologyamp Technology vol 28 no 1 pp 135ndash142 2003
[8] H Nalbandi S Seiiedlou H R Ghasemzadeh andF Rangbar ldquoInnovative parallel airflow system for forced-aircooling of strawberriesrdquo Food and Bioproducts Processingvol 100 pp 440ndash449 2016
[9] J L OrsquoSullivan M J Ferrua R Love P VerbovenB Nicolaı and A East ldquoForced air cooling of polylinedhorticultural produce optimal cooling conditions andpackage designrdquo Postharvest Biology amp Technology vol 126pp 67ndash75 2017
[10] J Yan Y Song J Li and W Jiang ldquoForced-air precoolingtreatment enhanced antioxidant capacities of apricotsrdquoJournal of Food Processing and Preservation vol 42 no 1article e13320 2018
[11] M Jincy M Djanaguiraman P JeyakumarK S Subramanian S Jayasankar and G Paliyath ldquoInhibitionof phospholipase D enzyme activity through hexanal leads todelayed mango (Mangifera indica L) fruit ripening throughchanges in oxidants and antioxidant enzymes activityrdquo Sci-entia Horticulturae vol 218 pp 316ndash325 2017
[12] J Li G W Ma L Ma et al ldquoMultivariate analysis of fruitantioxidant activities of blackberry treated with 1-Methyl-cyclopropene or vacuum precoolingrdquo International Journal ofAnalytical Chemistry vol 2018 Article ID 2416461 5 pages2018
[13] P Sharma A B Jha R S Dubey andM Pessarakli ldquoReactiveoxygen species oxidative damage and antioxidative defensemechanism in plants under stressful conditionsrdquo Journal ofBotany vol 2012 Article ID 217037 26 pages 2012
[14] O Elloumi M Ghrab andM BenMimoun ldquoEffects of flowerbuds removal on seasonal starch storage and mobilization infruiting and non-fruiting branches of pistachio trees cvMateur under dry and warm climaterdquo Scientia Horticulturaevol 172 no 3 pp 19ndash25 2014
[15] K Liu J Liu H Li C Yuan J Zhong and Y Chen ldquoInfluenceof postharvest citric acid and chitosan coating treatment onripening attributes and expression of cell wall related genes incherimoya (Annona cherimola Mill) fruitrdquo Scientia Horti-culturae vol 198 no 10 pp 1ndash11 2016
[16] D M Hodges J M Delong C F Forney and R K PrangeldquoImproving the thiobarbituric acid-reactive-substances assayfor estimating lipid peroxidation in plant tissues containinganthocyanin and other interfering compoundsrdquo Plantavol 207 no 4 pp 604ndash611 1999
[17] J E Brehe andH B Burch ldquoEnzymatic assay for glutathionerdquoAnalytical Biochemistry vol 74 no 1 pp 189ndash197 1976
[18] D Prochazkova R K Sairam G C Srivastava andD V Singh ldquoOxidative stress and antioxidant activity as thebasis of senescence in maize leavesrdquo Plant Science vol 161no 4 pp 765ndash771 2001
[19] C Larrigaudiere I Lentheric J Puy and E Pinto ldquoBio-chemical characterisation of core browning and brown heartdisorders in pear bymultivariate analysisrdquo Postharvest Biologyand Technology vol 31 no 1 pp 29ndash39 2004
Journal of Food Quality 11
[20] S Naima M R Khan and S Maria ldquoAntioxidant activitytotal phenolic and total flavonoid contents of whole plantextracts Torilis leptophylla Lrdquo BMC Complementary and Al-ternative Medicine vol 12 no 1 p 221 2012
[21] Y Nakano and K Asada ldquoPurification of ascorbate peroxi-dase in spinach chloroplasts its inactivation in ascorbate-depleted medium and reactivation by monodehydroascorbateradicalrdquo Plant amp Cell Physiology vol 28 no 1 pp 131ndash1401987
[22] C H Foyer and B Halliwell ldquoe presence of glutathione andglutathione reductase in chloroplasts a proposed role inascorbic acid metabolismrdquo Planta vol 133 no 1 pp 21ndash251976
[23] F Zhu Z Yun Q Ma et al ldquoEffects of exogenous 24-epi-brassinolide treatment on postharvest quality and resistanceof Satsuma Mandarin (Citrus unshiu)rdquo Postharvest Biologyand Technology vol 100 pp 8ndash15 2015
[24] S Zhu and B Ma ldquoBenzothiadiazole- or methyl jasmonate-induced resistance toColletotrichum musaein harvested ba-nana fruit is related to elevated defense enzyme activitiesrdquolteJournal of Horticultural Science and Biotechnology vol 82no 4 pp 500ndash506 2007
[25] J-W Han J-P Qian C-J Zhao X-T Yang and B-L FanldquoMathematical modelling of cooling efficiency of ventilatedpackaging integral performance evaluationrdquo InternationalJournal of Heat andMass Transfer vol 111 pp 386ndash397 2017
[26] X Zheng L Ye T Jiang G Jing and J Li ldquoLimiting thedeterioration of mango fruit during storage at room tem-perature by oxalate treatmentrdquo Food Chemistry vol 130no 2 pp 279ndash285 2012
[27] J K Dhemre D P Waskar S D Masalkar andR S Gaikwad ldquoEffect of post-harvest treatments on shelf lifeand quality of mango cv Kesar in cool storage and ambientconditionsrdquo Agricultural Science Digest vol 25 no 2pp 79ndash84 2005
[28] M Fleancu ldquoCorrelations among some physiological pro-cesses in apple fruit during growing and maturation pro-cessesrdquo International Journal of Agriculture amp Biologyvol 8530 pp 9ndash4 2007
[29] H Vergara-Domınguez J J Rıos B Gandul-Rojas andM Roca ldquoChlorophyll catabolism in olive fruits (var Arbe-quina and Hojiblanca) during maturationrdquo Food Chemistryvol 212 pp 604ndash611 2016
[30] S S Zaharah and Z Singh ldquoPostharvest nitric oxide fumi-gation alleviates chilling injury delays fruit ripening andmaintains quality in cold-stored ldquoKensington Priderdquo mangordquoPostharvest Biology and Technology vol 60 no 3 pp 202ndash210 2011
[31] M Babalar M Asghari A Talaei and A Khosroshahi ldquoEffectof pre- and postharvest salicylic acid treatment on ethyleneproduction fungal decay and overall quality of Selva strawberryfruitrdquo Food Chemistry vol 105 no 2 pp 449ndash453 2007
[32] A Ali M K Ong and C F Forney ldquoEffect of ozone pre-conditioning on quality and antioxidant capacity of papayafruit during ambient storagerdquo Food Chemistry vol 142 no 2pp 19ndash26 2014
[33] X Wang S Gu and B Chen ldquoe mechanism of cholesterol-effect on the quality of green asparagus (Asparagus officinalisL) spears during low temperature storagerdquo Scientia Horti-culturae vol 231 pp 36ndash42 2018
[34] M Sivapriya and S Leela ldquoIsolation and purification of anovel antioxidant protein from the water extract of Sundakai(Solanum torvum) seedsrdquo Food Chemistry vol 104 no 2pp 510ndash517 2007
[35] F V Breusegem E Vranova J F Dat and D Inze ldquoe roleof active oxygen species in plant signal transductionrdquo PlantScience vol 161 no 3 pp 405ndash414 2001
[36] L M Segal and R A Wilson ldquoReactive oxygen speciesmetabolism and plant-fungal interactionsrdquo Fungal Geneticsand Biology vol 110 pp 1ndash9 2018
[37] Y Wang X Xie and L E Long ldquoe effect of postharvestcalcium application in hydro-cooling water on tissue calciumcontent biochemical changes and quality attributes of sweetcherry fruitrdquo Food Chemistry vol 160 no 11 pp 22ndash30 2014
[38] Y Imahori J Bai and E Baldwin ldquoAntioxidative responses ofripe tomato fruit to postharvest chilling and heating treat-mentsrdquo Scientia Horticulturae vol 198 no 75 pp 398ndash4062016
outside stresses reactive oxygen species metabolism balanceis broken free radicals are accumulated in abundance andthe peroxidation of membrane lipid is improved or aggra-vated all of which induce the fruit senescence [13] O2minus is akind of reactive oxygen species with relatively high viru-lence playing an important role in horticultural plant rip-ening and senescence processes particularly in membranedeterioration [35] is study showed that the O2minus pro-duction rate in mango fruits increased rapidly at the end ofstorage leading to senescence of mango Precooling treat-ment inhibited the increase of O2minus production rate andsubsequent fruit senescence Moreover being as the productof membrane lipid peroxidation MDA was usually used toevaluate the degree of membrane damage [36] and lipidperoxidation [37] In this study MDA content was increasedrapidly during the later storage period and was always at ahigher levelis veried that the mango fruitrsquos cellulose was
peroxidated and the integrity of the cell membrane wasdestroyed
ere are many active oxygen removal systems in planttissue e excessive active oxygen was eliminated by dif-ferent antioxidant enzymes [13] O2minus can be transformedinto H2O2 by SOD in the plants is study found thatprecooling treatment enhanced the SOD activity of mangofruits during storage at might be why precooled fruit hadlower O2minus production rate than control fruits In additionwe also found that precooled fruits had higher CAT andPOD activities than control fruits We could include thatprecooled fruits had lower reactive oxygen species thancontrol fruits However there was no signicant dierenceof APX between the precooled fruits and control fruits in thisstudy is could be due to the higher activity of CAT andPOD in mango fruits and APX had not played a major partin elimination of H2O2 erefore the balance betweenSOD POD CAT and APX activities in plants is importantfor determining the steady-state levels of H2O2 and ROS[38]
Glutathione (GSH) is also a very important kind of theactive oxygen removal material [35] In plant tissue GSHcan reduce dehydroascorbic acid (DHA) to ascorbic acid(ASA) and ASA can eliminate H2O2 directly Glutathionereductase (GR) is the key enzyme involved in the GSHgeneration from oxidized glutathione (GSSC) [13 35] isstudy showed that precooled fruits had a higher GSHcontent and GR activity than control fruits during thestorage all of which contributed to the delay of fruit ripeningand senescence
Previous reports indicated that PPO was directly relatedto browning and decay Decrease in its activity would lead toan induced resistance to browning and decay [25] In normalcircumstances PPO usually exists in organelles membraneand cell membrane so the PPO activity is low [13]When thestructure of cell membrane is destroyed PPO is released andthe activity increases In this study the PPO activity in
20
40
60
80
0 5 10 15 20
GSH
cont
ent (
nmol
middotgndash1
middotFW
)
Days of storage
ControlTreatment
(a)
ControlTreatment
0
100
200
300
0 5 10 15 20
GR
activ
ity (U
middotgndash1
middotFW
middotmin
ndash1)
Days of storage
(b)
Figure 9 Eects of forced air precooling treatment on GSH content (a) and GR activity (b)
0
2
4
6
8
10
12
14
0 5 10 15 20
PPO
activ
ity (U
middotgndash1
middotFW
middotmin
ndash1)
Days of storage
ControlTreatment
Figure 10 Eects of forced air precooling treatment on PPOactivity
10 Journal of Food Quality
precooled fruits was always kept in a low level and thismight be because the precooling treatment enhanced theantioxidant defense capabilities and helped to maintain cellintegrity
5 Conclusion
Mango fruitrsquos quality was significantly improved by forcedair precooling treatment Precooling treatment delayed fruitripening and senescence with inhibition of ROS and en-hancement of active oxygen removal enzymes such as su-peroxide dismutase (SOD) catalase (CAT) peroxidase(POD) glutathione reductase (GR) and polyphenoloxidase(PPO) e firmness was maintained and fruit decay wasinhibited during storage ese results indicate that forcedair precooling treatment could maintain mango fruitrsquosquality by enhancing antioxidant activity and delaying fruitripening erefore it is suggested that mango fruits shouldbe precooled immediately after harvest for maintaining fruitquality and prolonging shelf-life
Data Availability
e data used to support the findings of this study areavailable from the corresponding author upon request
Conflicts of Interest
e authors declare that there are no conflicts of interestassociated with the publication of this manuscript
Acknowledgments
is research was supported by Support Project of High-Level Teachers in Beijing Municipal Universities in thePeriod of the 13th Five-Year Plan (CITampTCD201704037)Construction of Scientific Research Innovation ServiceAbility-Basic Scientific Research Operating Expense-FoodFeature Project (PXM2018_014213_000033) and SupportProject of High-Level Teachers in Beijing Municipal Uni-versities (IDHT20180506)
References
[1] Q Han H Gao H Chen X Fang and W Wu ldquoPrecoolingand ozone treatments affects postharvest quality of blackmulberry (Morus nigra) fruitsrdquo Food Chemistry vol 221pp 1947ndash1953 2017
[2] G M Cosme Silva W B Silva D B Medeiros et al ldquoechitosan affects severely the carbon metabolism in mango(Mangifera indica L cv Palmer) fruit during storagerdquo FoodChemistry vol 237 pp 372ndash378 2017
[3] J Li Q Li X J Lei et al ldquoEffects of wax coating on themoisture loss of cucumbers at different storage temperaturesrdquoJournal of food quality vol 2018 no 12 pp 1ndash6 2018
[4] H J Zhou Z W YE M S Su and J H Du ldquoEffects of lowtemperature and forced air precooling on precooling per-formance of different varieties of peach fruitsrdquo Storage ampProcess vol 15 pp 16ndash19 2015
[5] A Rab H Rehman I Haq M Sajid K Nawab and K AlildquoHarvest stages and pre-cooling influence the quality and
storage life of tomato fruitrdquo Journal Animal amp Plant Sciencevol 23 no 5 pp 1347ndash1357 2013
[6] M Zhou K H Ndeurumio L Zhao and Z Hu ldquoImpact ofprecooling and controlled-atmosphere storage on γ--aminobutyric acid (GABA) accumulation in longan (dimo-carpus longan lour) fruitrdquo Journal of Agricultural and FoodChemistry vol 64 no 33 pp 6443ndash6450 2016
[7] D Martinez-Romero S Castillo and D Valero ldquoForced aircooling applied before fruit handling to prevent mechanicaldamage of plums (Prunus salicina Lindl)rdquo Postharvest Biologyamp Technology vol 28 no 1 pp 135ndash142 2003
[8] H Nalbandi S Seiiedlou H R Ghasemzadeh andF Rangbar ldquoInnovative parallel airflow system for forced-aircooling of strawberriesrdquo Food and Bioproducts Processingvol 100 pp 440ndash449 2016
[9] J L OrsquoSullivan M J Ferrua R Love P VerbovenB Nicolaı and A East ldquoForced air cooling of polylinedhorticultural produce optimal cooling conditions andpackage designrdquo Postharvest Biology amp Technology vol 126pp 67ndash75 2017
[10] J Yan Y Song J Li and W Jiang ldquoForced-air precoolingtreatment enhanced antioxidant capacities of apricotsrdquoJournal of Food Processing and Preservation vol 42 no 1article e13320 2018
[11] M Jincy M Djanaguiraman P JeyakumarK S Subramanian S Jayasankar and G Paliyath ldquoInhibitionof phospholipase D enzyme activity through hexanal leads todelayed mango (Mangifera indica L) fruit ripening throughchanges in oxidants and antioxidant enzymes activityrdquo Sci-entia Horticulturae vol 218 pp 316ndash325 2017
[12] J Li G W Ma L Ma et al ldquoMultivariate analysis of fruitantioxidant activities of blackberry treated with 1-Methyl-cyclopropene or vacuum precoolingrdquo International Journal ofAnalytical Chemistry vol 2018 Article ID 2416461 5 pages2018
[13] P Sharma A B Jha R S Dubey andM Pessarakli ldquoReactiveoxygen species oxidative damage and antioxidative defensemechanism in plants under stressful conditionsrdquo Journal ofBotany vol 2012 Article ID 217037 26 pages 2012
[14] O Elloumi M Ghrab andM BenMimoun ldquoEffects of flowerbuds removal on seasonal starch storage and mobilization infruiting and non-fruiting branches of pistachio trees cvMateur under dry and warm climaterdquo Scientia Horticulturaevol 172 no 3 pp 19ndash25 2014
[15] K Liu J Liu H Li C Yuan J Zhong and Y Chen ldquoInfluenceof postharvest citric acid and chitosan coating treatment onripening attributes and expression of cell wall related genes incherimoya (Annona cherimola Mill) fruitrdquo Scientia Horti-culturae vol 198 no 10 pp 1ndash11 2016
[16] D M Hodges J M Delong C F Forney and R K PrangeldquoImproving the thiobarbituric acid-reactive-substances assayfor estimating lipid peroxidation in plant tissues containinganthocyanin and other interfering compoundsrdquo Plantavol 207 no 4 pp 604ndash611 1999
[17] J E Brehe andH B Burch ldquoEnzymatic assay for glutathionerdquoAnalytical Biochemistry vol 74 no 1 pp 189ndash197 1976
[18] D Prochazkova R K Sairam G C Srivastava andD V Singh ldquoOxidative stress and antioxidant activity as thebasis of senescence in maize leavesrdquo Plant Science vol 161no 4 pp 765ndash771 2001
[19] C Larrigaudiere I Lentheric J Puy and E Pinto ldquoBio-chemical characterisation of core browning and brown heartdisorders in pear bymultivariate analysisrdquo Postharvest Biologyand Technology vol 31 no 1 pp 29ndash39 2004
Journal of Food Quality 11
[20] S Naima M R Khan and S Maria ldquoAntioxidant activitytotal phenolic and total flavonoid contents of whole plantextracts Torilis leptophylla Lrdquo BMC Complementary and Al-ternative Medicine vol 12 no 1 p 221 2012
[21] Y Nakano and K Asada ldquoPurification of ascorbate peroxi-dase in spinach chloroplasts its inactivation in ascorbate-depleted medium and reactivation by monodehydroascorbateradicalrdquo Plant amp Cell Physiology vol 28 no 1 pp 131ndash1401987
[22] C H Foyer and B Halliwell ldquoe presence of glutathione andglutathione reductase in chloroplasts a proposed role inascorbic acid metabolismrdquo Planta vol 133 no 1 pp 21ndash251976
[23] F Zhu Z Yun Q Ma et al ldquoEffects of exogenous 24-epi-brassinolide treatment on postharvest quality and resistanceof Satsuma Mandarin (Citrus unshiu)rdquo Postharvest Biologyand Technology vol 100 pp 8ndash15 2015
[24] S Zhu and B Ma ldquoBenzothiadiazole- or methyl jasmonate-induced resistance toColletotrichum musaein harvested ba-nana fruit is related to elevated defense enzyme activitiesrdquolteJournal of Horticultural Science and Biotechnology vol 82no 4 pp 500ndash506 2007
[25] J-W Han J-P Qian C-J Zhao X-T Yang and B-L FanldquoMathematical modelling of cooling efficiency of ventilatedpackaging integral performance evaluationrdquo InternationalJournal of Heat andMass Transfer vol 111 pp 386ndash397 2017
[26] X Zheng L Ye T Jiang G Jing and J Li ldquoLimiting thedeterioration of mango fruit during storage at room tem-perature by oxalate treatmentrdquo Food Chemistry vol 130no 2 pp 279ndash285 2012
[27] J K Dhemre D P Waskar S D Masalkar andR S Gaikwad ldquoEffect of post-harvest treatments on shelf lifeand quality of mango cv Kesar in cool storage and ambientconditionsrdquo Agricultural Science Digest vol 25 no 2pp 79ndash84 2005
[28] M Fleancu ldquoCorrelations among some physiological pro-cesses in apple fruit during growing and maturation pro-cessesrdquo International Journal of Agriculture amp Biologyvol 8530 pp 9ndash4 2007
[29] H Vergara-Domınguez J J Rıos B Gandul-Rojas andM Roca ldquoChlorophyll catabolism in olive fruits (var Arbe-quina and Hojiblanca) during maturationrdquo Food Chemistryvol 212 pp 604ndash611 2016
[30] S S Zaharah and Z Singh ldquoPostharvest nitric oxide fumi-gation alleviates chilling injury delays fruit ripening andmaintains quality in cold-stored ldquoKensington Priderdquo mangordquoPostharvest Biology and Technology vol 60 no 3 pp 202ndash210 2011
[31] M Babalar M Asghari A Talaei and A Khosroshahi ldquoEffectof pre- and postharvest salicylic acid treatment on ethyleneproduction fungal decay and overall quality of Selva strawberryfruitrdquo Food Chemistry vol 105 no 2 pp 449ndash453 2007
[32] A Ali M K Ong and C F Forney ldquoEffect of ozone pre-conditioning on quality and antioxidant capacity of papayafruit during ambient storagerdquo Food Chemistry vol 142 no 2pp 19ndash26 2014
[33] X Wang S Gu and B Chen ldquoe mechanism of cholesterol-effect on the quality of green asparagus (Asparagus officinalisL) spears during low temperature storagerdquo Scientia Horti-culturae vol 231 pp 36ndash42 2018
[34] M Sivapriya and S Leela ldquoIsolation and purification of anovel antioxidant protein from the water extract of Sundakai(Solanum torvum) seedsrdquo Food Chemistry vol 104 no 2pp 510ndash517 2007
[35] F V Breusegem E Vranova J F Dat and D Inze ldquoe roleof active oxygen species in plant signal transductionrdquo PlantScience vol 161 no 3 pp 405ndash414 2001
[36] L M Segal and R A Wilson ldquoReactive oxygen speciesmetabolism and plant-fungal interactionsrdquo Fungal Geneticsand Biology vol 110 pp 1ndash9 2018
[37] Y Wang X Xie and L E Long ldquoe effect of postharvestcalcium application in hydro-cooling water on tissue calciumcontent biochemical changes and quality attributes of sweetcherry fruitrdquo Food Chemistry vol 160 no 11 pp 22ndash30 2014
[38] Y Imahori J Bai and E Baldwin ldquoAntioxidative responses ofripe tomato fruit to postharvest chilling and heating treat-mentsrdquo Scientia Horticulturae vol 198 no 75 pp 398ndash4062016
precooled fruits was always kept in a low level and thismight be because the precooling treatment enhanced theantioxidant defense capabilities and helped to maintain cellintegrity
5 Conclusion
Mango fruitrsquos quality was significantly improved by forcedair precooling treatment Precooling treatment delayed fruitripening and senescence with inhibition of ROS and en-hancement of active oxygen removal enzymes such as su-peroxide dismutase (SOD) catalase (CAT) peroxidase(POD) glutathione reductase (GR) and polyphenoloxidase(PPO) e firmness was maintained and fruit decay wasinhibited during storage ese results indicate that forcedair precooling treatment could maintain mango fruitrsquosquality by enhancing antioxidant activity and delaying fruitripening erefore it is suggested that mango fruits shouldbe precooled immediately after harvest for maintaining fruitquality and prolonging shelf-life
Data Availability
e data used to support the findings of this study areavailable from the corresponding author upon request
Conflicts of Interest
e authors declare that there are no conflicts of interestassociated with the publication of this manuscript
Acknowledgments
is research was supported by Support Project of High-Level Teachers in Beijing Municipal Universities in thePeriod of the 13th Five-Year Plan (CITampTCD201704037)Construction of Scientific Research Innovation ServiceAbility-Basic Scientific Research Operating Expense-FoodFeature Project (PXM2018_014213_000033) and SupportProject of High-Level Teachers in Beijing Municipal Uni-versities (IDHT20180506)
References
[1] Q Han H Gao H Chen X Fang and W Wu ldquoPrecoolingand ozone treatments affects postharvest quality of blackmulberry (Morus nigra) fruitsrdquo Food Chemistry vol 221pp 1947ndash1953 2017
[2] G M Cosme Silva W B Silva D B Medeiros et al ldquoechitosan affects severely the carbon metabolism in mango(Mangifera indica L cv Palmer) fruit during storagerdquo FoodChemistry vol 237 pp 372ndash378 2017
[3] J Li Q Li X J Lei et al ldquoEffects of wax coating on themoisture loss of cucumbers at different storage temperaturesrdquoJournal of food quality vol 2018 no 12 pp 1ndash6 2018
[4] H J Zhou Z W YE M S Su and J H Du ldquoEffects of lowtemperature and forced air precooling on precooling per-formance of different varieties of peach fruitsrdquo Storage ampProcess vol 15 pp 16ndash19 2015
[5] A Rab H Rehman I Haq M Sajid K Nawab and K AlildquoHarvest stages and pre-cooling influence the quality and
storage life of tomato fruitrdquo Journal Animal amp Plant Sciencevol 23 no 5 pp 1347ndash1357 2013
[6] M Zhou K H Ndeurumio L Zhao and Z Hu ldquoImpact ofprecooling and controlled-atmosphere storage on γ--aminobutyric acid (GABA) accumulation in longan (dimo-carpus longan lour) fruitrdquo Journal of Agricultural and FoodChemistry vol 64 no 33 pp 6443ndash6450 2016
[7] D Martinez-Romero S Castillo and D Valero ldquoForced aircooling applied before fruit handling to prevent mechanicaldamage of plums (Prunus salicina Lindl)rdquo Postharvest Biologyamp Technology vol 28 no 1 pp 135ndash142 2003
[8] H Nalbandi S Seiiedlou H R Ghasemzadeh andF Rangbar ldquoInnovative parallel airflow system for forced-aircooling of strawberriesrdquo Food and Bioproducts Processingvol 100 pp 440ndash449 2016
[9] J L OrsquoSullivan M J Ferrua R Love P VerbovenB Nicolaı and A East ldquoForced air cooling of polylinedhorticultural produce optimal cooling conditions andpackage designrdquo Postharvest Biology amp Technology vol 126pp 67ndash75 2017
[10] J Yan Y Song J Li and W Jiang ldquoForced-air precoolingtreatment enhanced antioxidant capacities of apricotsrdquoJournal of Food Processing and Preservation vol 42 no 1article e13320 2018
[11] M Jincy M Djanaguiraman P JeyakumarK S Subramanian S Jayasankar and G Paliyath ldquoInhibitionof phospholipase D enzyme activity through hexanal leads todelayed mango (Mangifera indica L) fruit ripening throughchanges in oxidants and antioxidant enzymes activityrdquo Sci-entia Horticulturae vol 218 pp 316ndash325 2017
[12] J Li G W Ma L Ma et al ldquoMultivariate analysis of fruitantioxidant activities of blackberry treated with 1-Methyl-cyclopropene or vacuum precoolingrdquo International Journal ofAnalytical Chemistry vol 2018 Article ID 2416461 5 pages2018
[13] P Sharma A B Jha R S Dubey andM Pessarakli ldquoReactiveoxygen species oxidative damage and antioxidative defensemechanism in plants under stressful conditionsrdquo Journal ofBotany vol 2012 Article ID 217037 26 pages 2012
[14] O Elloumi M Ghrab andM BenMimoun ldquoEffects of flowerbuds removal on seasonal starch storage and mobilization infruiting and non-fruiting branches of pistachio trees cvMateur under dry and warm climaterdquo Scientia Horticulturaevol 172 no 3 pp 19ndash25 2014
[15] K Liu J Liu H Li C Yuan J Zhong and Y Chen ldquoInfluenceof postharvest citric acid and chitosan coating treatment onripening attributes and expression of cell wall related genes incherimoya (Annona cherimola Mill) fruitrdquo Scientia Horti-culturae vol 198 no 10 pp 1ndash11 2016
[16] D M Hodges J M Delong C F Forney and R K PrangeldquoImproving the thiobarbituric acid-reactive-substances assayfor estimating lipid peroxidation in plant tissues containinganthocyanin and other interfering compoundsrdquo Plantavol 207 no 4 pp 604ndash611 1999
[17] J E Brehe andH B Burch ldquoEnzymatic assay for glutathionerdquoAnalytical Biochemistry vol 74 no 1 pp 189ndash197 1976
[18] D Prochazkova R K Sairam G C Srivastava andD V Singh ldquoOxidative stress and antioxidant activity as thebasis of senescence in maize leavesrdquo Plant Science vol 161no 4 pp 765ndash771 2001
[19] C Larrigaudiere I Lentheric J Puy and E Pinto ldquoBio-chemical characterisation of core browning and brown heartdisorders in pear bymultivariate analysisrdquo Postharvest Biologyand Technology vol 31 no 1 pp 29ndash39 2004
Journal of Food Quality 11
[20] S Naima M R Khan and S Maria ldquoAntioxidant activitytotal phenolic and total flavonoid contents of whole plantextracts Torilis leptophylla Lrdquo BMC Complementary and Al-ternative Medicine vol 12 no 1 p 221 2012
[21] Y Nakano and K Asada ldquoPurification of ascorbate peroxi-dase in spinach chloroplasts its inactivation in ascorbate-depleted medium and reactivation by monodehydroascorbateradicalrdquo Plant amp Cell Physiology vol 28 no 1 pp 131ndash1401987
[22] C H Foyer and B Halliwell ldquoe presence of glutathione andglutathione reductase in chloroplasts a proposed role inascorbic acid metabolismrdquo Planta vol 133 no 1 pp 21ndash251976
[23] F Zhu Z Yun Q Ma et al ldquoEffects of exogenous 24-epi-brassinolide treatment on postharvest quality and resistanceof Satsuma Mandarin (Citrus unshiu)rdquo Postharvest Biologyand Technology vol 100 pp 8ndash15 2015
[24] S Zhu and B Ma ldquoBenzothiadiazole- or methyl jasmonate-induced resistance toColletotrichum musaein harvested ba-nana fruit is related to elevated defense enzyme activitiesrdquolteJournal of Horticultural Science and Biotechnology vol 82no 4 pp 500ndash506 2007
[25] J-W Han J-P Qian C-J Zhao X-T Yang and B-L FanldquoMathematical modelling of cooling efficiency of ventilatedpackaging integral performance evaluationrdquo InternationalJournal of Heat andMass Transfer vol 111 pp 386ndash397 2017
[26] X Zheng L Ye T Jiang G Jing and J Li ldquoLimiting thedeterioration of mango fruit during storage at room tem-perature by oxalate treatmentrdquo Food Chemistry vol 130no 2 pp 279ndash285 2012
[27] J K Dhemre D P Waskar S D Masalkar andR S Gaikwad ldquoEffect of post-harvest treatments on shelf lifeand quality of mango cv Kesar in cool storage and ambientconditionsrdquo Agricultural Science Digest vol 25 no 2pp 79ndash84 2005
[28] M Fleancu ldquoCorrelations among some physiological pro-cesses in apple fruit during growing and maturation pro-cessesrdquo International Journal of Agriculture amp Biologyvol 8530 pp 9ndash4 2007
[29] H Vergara-Domınguez J J Rıos B Gandul-Rojas andM Roca ldquoChlorophyll catabolism in olive fruits (var Arbe-quina and Hojiblanca) during maturationrdquo Food Chemistryvol 212 pp 604ndash611 2016
[30] S S Zaharah and Z Singh ldquoPostharvest nitric oxide fumi-gation alleviates chilling injury delays fruit ripening andmaintains quality in cold-stored ldquoKensington Priderdquo mangordquoPostharvest Biology and Technology vol 60 no 3 pp 202ndash210 2011
[31] M Babalar M Asghari A Talaei and A Khosroshahi ldquoEffectof pre- and postharvest salicylic acid treatment on ethyleneproduction fungal decay and overall quality of Selva strawberryfruitrdquo Food Chemistry vol 105 no 2 pp 449ndash453 2007
[32] A Ali M K Ong and C F Forney ldquoEffect of ozone pre-conditioning on quality and antioxidant capacity of papayafruit during ambient storagerdquo Food Chemistry vol 142 no 2pp 19ndash26 2014
[33] X Wang S Gu and B Chen ldquoe mechanism of cholesterol-effect on the quality of green asparagus (Asparagus officinalisL) spears during low temperature storagerdquo Scientia Horti-culturae vol 231 pp 36ndash42 2018
[34] M Sivapriya and S Leela ldquoIsolation and purification of anovel antioxidant protein from the water extract of Sundakai(Solanum torvum) seedsrdquo Food Chemistry vol 104 no 2pp 510ndash517 2007
[35] F V Breusegem E Vranova J F Dat and D Inze ldquoe roleof active oxygen species in plant signal transductionrdquo PlantScience vol 161 no 3 pp 405ndash414 2001
[36] L M Segal and R A Wilson ldquoReactive oxygen speciesmetabolism and plant-fungal interactionsrdquo Fungal Geneticsand Biology vol 110 pp 1ndash9 2018
[37] Y Wang X Xie and L E Long ldquoe effect of postharvestcalcium application in hydro-cooling water on tissue calciumcontent biochemical changes and quality attributes of sweetcherry fruitrdquo Food Chemistry vol 160 no 11 pp 22ndash30 2014
[38] Y Imahori J Bai and E Baldwin ldquoAntioxidative responses ofripe tomato fruit to postharvest chilling and heating treat-mentsrdquo Scientia Horticulturae vol 198 no 75 pp 398ndash4062016
[20] S Naima M R Khan and S Maria ldquoAntioxidant activitytotal phenolic and total flavonoid contents of whole plantextracts Torilis leptophylla Lrdquo BMC Complementary and Al-ternative Medicine vol 12 no 1 p 221 2012
[21] Y Nakano and K Asada ldquoPurification of ascorbate peroxi-dase in spinach chloroplasts its inactivation in ascorbate-depleted medium and reactivation by monodehydroascorbateradicalrdquo Plant amp Cell Physiology vol 28 no 1 pp 131ndash1401987
[22] C H Foyer and B Halliwell ldquoe presence of glutathione andglutathione reductase in chloroplasts a proposed role inascorbic acid metabolismrdquo Planta vol 133 no 1 pp 21ndash251976
[23] F Zhu Z Yun Q Ma et al ldquoEffects of exogenous 24-epi-brassinolide treatment on postharvest quality and resistanceof Satsuma Mandarin (Citrus unshiu)rdquo Postharvest Biologyand Technology vol 100 pp 8ndash15 2015
[24] S Zhu and B Ma ldquoBenzothiadiazole- or methyl jasmonate-induced resistance toColletotrichum musaein harvested ba-nana fruit is related to elevated defense enzyme activitiesrdquolteJournal of Horticultural Science and Biotechnology vol 82no 4 pp 500ndash506 2007
[25] J-W Han J-P Qian C-J Zhao X-T Yang and B-L FanldquoMathematical modelling of cooling efficiency of ventilatedpackaging integral performance evaluationrdquo InternationalJournal of Heat andMass Transfer vol 111 pp 386ndash397 2017
[26] X Zheng L Ye T Jiang G Jing and J Li ldquoLimiting thedeterioration of mango fruit during storage at room tem-perature by oxalate treatmentrdquo Food Chemistry vol 130no 2 pp 279ndash285 2012
[27] J K Dhemre D P Waskar S D Masalkar andR S Gaikwad ldquoEffect of post-harvest treatments on shelf lifeand quality of mango cv Kesar in cool storage and ambientconditionsrdquo Agricultural Science Digest vol 25 no 2pp 79ndash84 2005
[28] M Fleancu ldquoCorrelations among some physiological pro-cesses in apple fruit during growing and maturation pro-cessesrdquo International Journal of Agriculture amp Biologyvol 8530 pp 9ndash4 2007
[29] H Vergara-Domınguez J J Rıos B Gandul-Rojas andM Roca ldquoChlorophyll catabolism in olive fruits (var Arbe-quina and Hojiblanca) during maturationrdquo Food Chemistryvol 212 pp 604ndash611 2016
[30] S S Zaharah and Z Singh ldquoPostharvest nitric oxide fumi-gation alleviates chilling injury delays fruit ripening andmaintains quality in cold-stored ldquoKensington Priderdquo mangordquoPostharvest Biology and Technology vol 60 no 3 pp 202ndash210 2011
[31] M Babalar M Asghari A Talaei and A Khosroshahi ldquoEffectof pre- and postharvest salicylic acid treatment on ethyleneproduction fungal decay and overall quality of Selva strawberryfruitrdquo Food Chemistry vol 105 no 2 pp 449ndash453 2007
[32] A Ali M K Ong and C F Forney ldquoEffect of ozone pre-conditioning on quality and antioxidant capacity of papayafruit during ambient storagerdquo Food Chemistry vol 142 no 2pp 19ndash26 2014
[33] X Wang S Gu and B Chen ldquoe mechanism of cholesterol-effect on the quality of green asparagus (Asparagus officinalisL) spears during low temperature storagerdquo Scientia Horti-culturae vol 231 pp 36ndash42 2018
[34] M Sivapriya and S Leela ldquoIsolation and purification of anovel antioxidant protein from the water extract of Sundakai(Solanum torvum) seedsrdquo Food Chemistry vol 104 no 2pp 510ndash517 2007
[35] F V Breusegem E Vranova J F Dat and D Inze ldquoe roleof active oxygen species in plant signal transductionrdquo PlantScience vol 161 no 3 pp 405ndash414 2001
[36] L M Segal and R A Wilson ldquoReactive oxygen speciesmetabolism and plant-fungal interactionsrdquo Fungal Geneticsand Biology vol 110 pp 1ndash9 2018
[37] Y Wang X Xie and L E Long ldquoe effect of postharvestcalcium application in hydro-cooling water on tissue calciumcontent biochemical changes and quality attributes of sweetcherry fruitrdquo Food Chemistry vol 160 no 11 pp 22ndash30 2014
[38] Y Imahori J Bai and E Baldwin ldquoAntioxidative responses ofripe tomato fruit to postharvest chilling and heating treat-mentsrdquo Scientia Horticulturae vol 198 no 75 pp 398ndash4062016
