Effect of Fluidized Bed Drying Temperature on Various Quality Attributes of Paddy

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Effect of Fluidized Bed Drying Temperature on Various Quality Attributesof PaddySupawan Tirawanichakula Somkiat Prachayawarakornb Warunee Varanyanondc PatchareeTungtrakulc Somchart Soponronnarita

a School of Energy and Materials King Mongkuts University of Technology Thonburi BangkokThailand b Faculty of Engineering King Mongkuts University of Technology Thonburi BangkokThailand c Institute of Food Research and Product Development Kasetsart University BangkeanBangkok Thailand

Online publication date 20 August 2004

To cite this Article Tirawanichakul Supawan Prachayawarakorn Somkiat Varanyanond Warunee TungtrakulPatcharee and Soponronnarit Somchart(2004) Effect of Fluidized Bed Drying Temperature on Various QualityAttributes of Paddy Drying Technology 22 7 1731 mdash 1754To link to this Article DOI 101081DRT-200025634URL httpdxdoiorg101081DRT-200025634

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DRYING TECHNOLOGY

Vol 22 No 7 pp 1731ndash1754 2004

Effect of Fluidized Bed Drying Temperature on

Various Quality Attributes of Paddy

Supawan Tirawanichakul1 Somkiat Prachayawarakorn2

Warunee Varanyanond3 Patcharee Tungtrakul3 and

Somchart Soponronnarit1

1School of Energy and Materials and2Faculty of Engineering King Mongkutrsquos University of Technology

Thonburi Bangkok Thailand3Institute of Food Research and Product Development Kasetsart

University Bangkean Bangkok Thailand

ABSTRACT

As reported by many researchers it was found that fluidized bed

paddy drying using high drying air temperatures of over 100C

affected the head rice yield and whiteness of dried rice However

only a few studies on fluidized bed paddy drying with drying air

temperatures below 100C were so far reported The main objective

of this work was therefore to study the effect of fluidized bed drying

air temperature on various quality parameters of Suphanburi 1 and

Correspondence Supawan Tirawanichakul School of Energy and Materials

King Mongkutrsquos University of Technology Thonburi Bangkok 10140 Thailand

Fax thorn662-470-8623 E-mail supawanvachiramonhotmailcom

1731

DOI 101081DRT-200025634 0737-3937 (Print) 1532-2300 (Online)

Copyright amp 2004 by Marcel Dekker Inc wwwdekkercom

Downloaded By [RMIT University Library] At 1020 4 May 2011

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Pathumthani 1 Indica rice Paddy was dried from the initial moisture

contents of 250 288 and 325 dry basis to 225 12 dry basis

using inlet drying air temperatures between 40 and 150C at 10C

step After fluidized bed drying paddy was tempered and followed

by ambient air aeration until its final moisture content was reduced

to 163 05 dry basis The results showed that the head rice

yield of Suphanburi 1 was significantly related to the inlet drying

temperature and initial moisture content whilst there was no

significant relationship between the head rice yield drying tempera-

ture and initial moisture content for Pathumthani 1 The whiteness of

the two rice varieties was slightly decreased with increase in drying

air temperature and initial moisture content It was also found that

the hardness of both cooked rice varieties exhibited insignificant

difference ( plt 005) comparing to rewetted rice which was gently

dried by ambient air aeration in thin layer The thermal analysis by

DSC also showed that partial gelatinization occurred during drying

at higher temperatures Using inlet drying air temperatures in the

range of 40ndash150C therefore did not affected the quality of cooked

rice and paddy The milling quality of paddy was also well

maintained

Key Words Amylose High-temperature drying Rice quality

Sensory evaluation

INTRODUCTION

The management of highly moist paddy with moisture content ofover 22 dry basis is an extremely serious problem in tropical countriessince high humid air condition can accelerate an excessive mould growthand yellowing of grains[1ndash4] To prevent paddy deterioration rapidreduction of moisture is essential and hot air drying seems to be the mostappropriate drying technique under such weather condition Someprevious researches recommended that high moisture content of paddyshould be first reduced to 22 dry basis within 24 h by hot air drying(using high temperature and short drying time) and then followed bynatural air drying at lower temperature[56] However the use of heatedair may damage some important grain qualities that are susceptible tothermal damage such as head rice yield whiteness physicochemicalproperties and nutritional values[7ndash9]

Hot air fluidized bed drying is one of the drying techniques thatprovides faster moisture reduction and uniformity of drying The rapiddrop in moisture content can however develop stresses inside the kernel

1732 Tirawanichakul et al


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causing the reduction of head rice yield[10] The head rice yield reductiondecreases the value of rice since broken rice has lower commercial valuesthan the complete one To reduce the thermal stresses and maintain thefull kernel tempering stage is recommended after the first stage ofdrying[11ndash14]

Although fluidized-bed dryer is well recognised in the grainindustries not much work is devoted to determining how this typedryer affects the quality of rice especially in the low drying temperaturerange Therefore the main objective of this article was to investigate theeffects of drying temperature and initial moisture content of paddy onvarious quality attributes of long grain rice varieties containing high andlow amylose contents The physical qualities tested were head rice yieldwhiteness of rice microstructure of rice kernel and germination Thechemical properties of rice were determined in terms of amylose contentand protein The texture of cooked rice as well as the thermogram of ricedetermined using a differential scanning calorimetry (DSC) wasinvestigated Finally overall acceptability of cooked rice by sensoryevaluation was also determined

EXPERIMENTAL SET-UP

MATERIALS AND METHODS

1 Experimental Set-up

Figure 1 shows the schematic diagram of a batch fluidized bed dryerused in the present study The dryer consists of a cylindrical shapeddrying chamber a 16 kW electric heating unit and a backward curvedblade centrifugal fan driven by a 15 kW motor The inlet drying airtemperature was controlled by a PID controller with an accuracy of1C A mechanical variable speed unit was used for regulating air flowrate A constant air velocity of 25ms was used for the bed of rice of95 cm The final moisture content required in the present study wasapproximately 225 dry basis as recommended by Poomsa-ad et al[6]

2 Materials

Two varieties of long grain rough rice (Suphanburi 1 andPathumthani 1) provided by the Rice Research Institute atPathumthani province Thailand were rewetted mixed and kept in acold storage at a temperature range of 4ndash6C for one week prior to the

Effect of Fluidized Bed Drying Temperature 1733


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start of each experiment The desired initial moisture content of rewettedpaddy was about 25ndash33 dry basis The local varieties of Suphanburi 1and Pathumthani 1 contain amylose contents of 25ndash27 and 15ndash18respectively Before starting the experiments paddy was placed in anambient environment until the thermal equilibrium was reached

2 Methods

21 Paddy Drying Condition

Figure 2 illustrates a schematic diagram of the drying scheduleused in this work Wet paddy was first dried using a fluidized beddryer by varying inlet air temperatures between 40 and 150C with 10Cincrement It was subsequently tempered for 30min[15] Duringtempering dried paddy was placed in a sealed glass bottle with ano-ring and kept in an oven at the same temperature as the grain

Figure 1 A schematic diagram of a batch fluidized bed dryer



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temperature The tempering process was performed to relax some ofthermal stresses developed during the first-stage drying

To measure the grain temperature paddy sample was taken out fromthe fluidized bed drying chamber at the end of drying time correspond-ing to the final moisture content as aforementioned and then measuredwhen it was kept in the well-insulated vessel This temperature was usedfor the tempering grain By this measuring it was concluded that at theinlet drying air temperature ranges of 40 to 90C the average graintemperature corresponded to the range of 38 to 75C respectively Forthe inlet drying air temperature ranges of 100 to 150C the average graintemperature was in the range of 83 to 89C respectively

After tempering paddy was taken out of the sealed bottle andventilated immediately with a constant ambient airflow rate of 015msuntil its moisture content reached 163 05 dry basis as recommendedby Soponronnarit[16] A K-type thermocouple used for measuring thetemperature of the bed was connected to a data logger with an accuracyof 1C The determination of paddy moisture content was performedaccording to the AOAC method[17] Air velocity was measured by a hotwire anemometer with a precision of 01ms

22 Quality of Rice

All qualities of rice samples after drying were determined comparingto the rewetted rice sample (so-called control rice) which was gently driedby ambient air ventilation in thin-layer The various qualities of paddy

Fluidized bed drying

Tempering30 minutes

Ambient air ventilation

Figure 2 A schematic diagram of a fluidized bed drying system



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were analyzed as follows

(a) Head Rice YieldThe determination of head rice yield was performed according to the

USDA method[18] Head rice yield was calculated by dividing the headrice weight by the initial rough rice weight This value was determinedin duplicate

(b) Microstructure and Thermal Property of RiceThe microstructure of rice kernel was characterized by a scanning

electron microscope (SEM) (JEOL model LV5600 England) at10ndash20 kV The magnification range was 200ndash4000 times

Thermal analysis of rice flour was determined by differentialscanning calorimetry (DSC) (Perkin Elmer model DSC-7 NorwalkUSA) The rice flour sample was heated from 40 to 95C at a scanningrate of 10Cmin From the DSC curve the onset temperature peaktemperature conclusion temperature and transition enthalpy wererecorded The degree of gelatinization of hydrothermally-treated riceflour was calculated by the following equation[19]

SGethTHORN frac14 1H

Hc

100 eth1THORN

where SGfrac14 degree of gelatinization ()Hfrac14 transition enthalpy of treated rice (Jg (dry weight basis))Hcfrac14 transition enthalpy of control rice (Jg (dry weight basis))

(c) Whiteness of RiceThe whiteness of milled rice was measured by a Satake milling meter

model MM-113 (Japan) This value was determined in duplicate

(d) Germination of PaddyBefore germination testing dried mature paddy samples were kept at

ambient air environment for 6 weeks The mature paddy samples (200seeds) were then used for each test The germination test followed theguidelines given by the Rice Research Institute at Pathumthani provinceThailand The experiments were performed in triplicate

(e) Chemical Quality of RiceAmylose was determined by simplified assay iodine colorimetric

method of Juliano[20] The content of protein was quantified as describedby AOAC method[17] These value was determined in duplicate



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(f) Textural Property of Cooked RiceHardness of cooked rice was determined by a bench-top texture

analyzer model TA-XT2i (Stable Micro Systems Ltd USA) A 30 gportion of each milled head rice sample was placed in an aluminumcylindrical cup (diameter of 7 cm and height of 7 cm) Before cooking therice sample was washed rinsed and then cooked with distilled water atrice-to-water weight ratios of 115 for Pathumthani 1 and 117 forSuphanburi 1[2122]

The initial height of the compression probe (Ottawa cell) was setat 120mm and the pretest speed test speed and post speed of probewere 15 05 and 10mms respectively The maximum force requiredfor compressing cooked rice to 90 of the initial height of 10mmwas indicated as the hardness of cooked rice The hardness value wasrepresented by the mean of 5 replications and the average valuewas expressed in kilogram unit

(i) Sensory Evaluation of Cooked RiceFor determination of the cooking quality 100 g of head rice was

washed with tap water and cooked in an electric cooker at a rice-to-waterratio of 118 by weight[22] The quality of cooked rice was evaluated onthe basis of its palatability Eight trained panelists from the Institute ofFood Research and Product Development Kasetsart UniversityThailand were invited to evaluate the overall acceptability of cookedrice using hedonic scale of 1ndash9 with the following scales 1frac14 extremelydislike 2frac14 very much dislike 3frac14moderately dislike 4frac14 slightly dislike5frac14 like nor dislike 6frac14 slightly like 7frac14moderately like 8frac14 very muchlike and 9frac14 extremely like Analysis of variance (ANOVA) andDuncanrsquos new multiple range test (DMRT) were used to evaluate theeffects of inlet drying air temperature on the quality of rice at 95confidence limit ( plt 005)

RESULTS AND DISCUSSION

1 Moisture Content and Drying Rate

For all experiments the moisture content of paddy after the firststage drying was set at 225 12 dry basis to avoid significant fissuringand subsequent breakage of rice However this moisture level is still notsafe for long-term storage and hence paddy needs to be dried furtherReducing moisture content from this level to 16 dry basis can be



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achieved by many means technique In common practice paddy wouldbe tempered at a suitable temperature[1523] and dried by any low-temperature drying technique until the desired final moisture content ofpaddy of 14ndash16 dry basis is reached[1315]

Thus in this work the tempering process at grain temperature wasperformed and the tempered duration was fixed at 30min Aftertempering paddy sample was thin-layer dried immediately by ambientair ventilation until the final moisture content was in range of 14ndash16dry basis resulting in minimal breakage and consequently a high headrice yield[23]

Figures 3(a) shows the drying rates of paddy at three initial moisturelevels of 250 288 and 325 dry basis for Suphanburi 1 at inlet dryingair temperatures of 40ndash150C It can be seen that the drying rates seem tobe independent of an initial moisture content indicating that the mainpart of moisture content above 250 dry basis existed only on theexterior surface thus allowing easier water removal without any inter-ference of disordered void spaces inside grain kernel during drying As isseen in Fig 3(b) the changes of drying rates for Pathumthani 1 with inletair temperatures of 40ndash150C and three initial moisture contents of 250288 and 325 dry basis show a similar trend to that found forSuphanburi 1

2 Quality of Rice

(a) Head Rice Yield of Rice

Figure 4 shows the relationship between inlet drying air temperatureand head rice yield The head rice yield after rewetting reduces to lowerlevel than that obtained before rewetting for both rice varieties Howeverthe amount of head rice yield reduction depends on the rice variety asobserved from the experiments Suphanburi 1 variety which containshigher amylose content has larger amount of broken kernel although thehead rice yield of both varieties before rewetting was nearly the same

When paddy kernels were subjected to drying at different airtemperatures the changing of head rice yield was rather complicated ForSuphanburi 1 variety as can be seen in Fig 4(a) at air temperaturesbelow 80C or grain temperatures below 70C head rice yield of paddysamples at three different initial moisture contents of 250 288 and325 dry basis was insignificantly different (when compared with thegently dried control sample) the values were between 43 and 45 Themaintained head rice yield could be explained by two possible reasons



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Firstly at low drying air temperatures of 40ndash50C which correspondedto the grain temperatures of 38ndash46C the moisture gradient developedinside a grain kernel during slow moisture reduction from any level to225 dry basis was not sufficiently large to develop fissures This is

0

2

4

6

8

40 50 60 70 80 90 100 110 120 130 140 150

Ave

rage

dry

ing

rate

(

dry

bas

ism

in) Initial MC 250 dry basis

Initial MC 288 dry basis


0

2

4

6

8

40 50 60 70 80 90 100 110 120 130 140 150

Inlet air temperature (oC)


Ave

rage

dry

ing

rate

(

dry

bas

ism

in)




(a)

(b)

Figure 3 Effect of inlet air temperature on average drying rate of Suphanburi 1

and Pathumthani 1 initial moisture contents were in the range of 250ndash325 dry

basis and final moisture content of 220 12 dry basis (after fluidized bed

drying) (a) Suphanburi 1 (b) Pathumthani 1



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reason why drying and tempering at the drying air temperatures belowthe glass transition temperature did not cause significant fissuring andsubsequent breakage of rice[23ndash25]

For drying temperatures in the range of 60 to 70C even though themoisture gradient was sufficiently large and hence induced stresses inside

40

45

50

55

40 50 60 70 80 90 100 110 120 130 140 150

Inlet air temperature (OC)

H

ead

rice

yie

ld

Initial MC 325 dry basis (HRY after rewetting = 440)



HRY before rewetting= 503

40

45

50

55

60

40 50 60 70 80 90 100 110 120 130 140 150


H

ead

rice

yie

ld





(a)

(b)

Figure 4 Effect of inlet air temperature on head rice yield of Suphanburi 1 and

Pathumthani 1 initial moisture contents were in the range of 250ndash325 dry

basis and final moisture contents of 220 12 dry basis (after fluidized bed




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the kernel tempering could still prevent the head rice yield reduction

since paddy was tempered at temperatures above 50C Under this

condition paddy was in its rubbery state[23] thus starch existed as a

rubbery material with higher expansion coefficients[2627] Several resear-

chers have reported that paddy drying at temperatures above 50C could

be detrimental to head rice yield if the moisture content drops larger than

3 percentages of moisture content in one drying pass and when tempering

is not included between drying stages[14232829] However in this study

the moisture content of paddy sample was removed around 68ndash105

during for the first-stage drying and hence the head rice yield was not

reduced when paddy was tempered at its own grain temperature after

fluidized bed drying Moreover the tempering duration of 30min used in

this study was sufficient large to remove large portion of moisture

content Consequently some of proteins or lipids might interact with

amylose and carbonyl compounds presented in paddy[30] resulting in

subsequent improvement of milling resistance of paddy[3132]

The change of head rice yield of paddy dried at a higher temperature

of 80C was quite different to that dried at lower temperatures however

At 80C the head rice yield was improved particularly at an initial

moisture content of 325 dry basis even higher than 47 as can be

seen in Fig 4(a) This value was indeed higher than that of control

sample The larger percentage head rice yield for high temperature

treated samples implies stronger intra-granular binding forces which

make the kernel more resistant to abrasive forces during milling This

improvement of binding forces amongst granules is caused by their

swelling together with the leaching out of amylose molecule from starch

granules into aqueous substrates[33] The swollen granules were then

gelatinized but only partially since the water content inside the kernel in

the present study was not enough for a complete gelatinizationIt is interesting to note that at each level of initial moisture content

the change of head rice yield with inlet drying air temperature for

Pathumthani 1 which contains lower amylose content was insignif-

icantly different over the entire drying temperature range the values laid

between 53 and 55 for an initial moisture contents of 250 and 288

dry basis and between 52 and 54 for an initial moisture content of

325 dry basis Such changes were not similar to those found for

Suphanburi 1 variety especially when drying at higher temperatures in

which the head rice yield did not show an increasing trend although

a high initial moisture content of 325 dry basis was employed

According to these results it may be indicated that the amylose content

significantly contributes to the improved intra-granular forces during



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gelatinization the lower the amount of amylose the lower the bindingforces are

As shown in Fig 4(b) the head rice yield for Pathumthani 1 samplewith an initial moisture content of 325 dry basis and dried at a highertemperature of 80C was lower than that of the other two initial moisturecontents The lower amount of full kernel was due to the dominantcontribution of stresses which consequently induced an irreversiblestructural damage although partial gelatinization occurred during dryingThis change was not similar to Suphanburi 1 samples in which the headrice yield became higher with the initial moisture content

(b) Microstructure and Thermal Analysis of Rice

To confirm the aforementioned occurrence of gelatinization themicrostructure of rice samples was examined by means of scanningelectron microscopy (SEM) The gelatinization enthalpy was alsodetermined by differential scanning calorimetry (DSC)

The results of SEM observation of the morphological changes ofstarch granules of Suphanburi 1 variety at various drying temperaturesare shown in Figs 5(andashd) As can be seen in Fig 5(a) the starch granulesin endosperms of control sample showed clearly the characteristicallyirregular polygons with diameters of 4ndash8 mm while Figs 5(bndashd) show themorphology of starch granules of dried rice kernel at inlet drying airtemperatures of 40 120 and 150C respectively Drying at low inlet air

Starch granules

(a) Rewetted rice (dried by ambient air aeration) (b) Fluidized bed dried rice at 40degC

(c) Fluidized bed dried rice at 120degC (d) Fluidized bed dried rice at 150degC

Figure 5 Scanning electron micrographs of Suphanburi 1 (initial MCfrac14 325

dry basis) at various inlet air temperatures



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temperature of 40C does not change the conformation of starchgranules as can be seen in Fig 5(b) comparing to the morphology ofstarch granules of the control sample (Fig 5(a))

As can be observed in Figs 5(cndashd) during drying at high inlet dryingair temperatures of 120 and 150C (the average grain temperature was inrange of 83 to 89C) starch granules obviously exhibited swelling This isdue to the fact that the bonding between amylose and amylopectinmolecules in starch granules was relaxed around their gelatinizationtemperatures of 68ndash78C[34] and leaching of amylose from starch granulesled to partial gelatinization[735] These combined characteristics ofthe granule segments to form network-like structures contributed to thestrong gel formation The structure of starch granules eventually disinte-grated and adjacent starch granules fused together to form the compositeclusters with homogeneous interior and low well defined polygonalboundaries The rice kernel appeared as dense and smooth layerthroughout its cross-sectional area as shown in Fig 5(d)

The above-mentioned partial gelatinization agreed well with theDSC results manifested by a certain degree of gelatinization as shown inTable 1 which shows the gelatinization and thermal properties ofSuphanburi 1 and Pathumthani 1 rice varieties The degree of gelatini-zation of both rice varieties after drying at 150C was different from thatof the reference sample The higher degree of gelatinization was observedin rice that had higher initial moisture content and the longer drying timeThe percentage degree of gelatinization for Suphanburi 1 andPathumthani 1 calculated by Eq (1) were in the range of 42ndash55 forthe initial moisture content of 325 dry basis and less than 20 for thelower initial moisture content of 288 dry basis

(c) Whiteness of Rice

Figure 6 shows the effects of drying air temperature and initialmoisture content on the whiteness of rice for Suphanburi 1 andPathumthani 1 After rewetting the whiteness value of Pathumthani 1rice sample remained the same as before rewetting whilst the color ofSuphanburi 1 rice sample became less luminous with the averagewhiteness value of 498 As paddy was subjected to drying at variousdrying air temperatures the whiteness of Pathumthani 1 with initialmoisture contents of 250 288 and 325 dry basis showed aninsignificant difference amongst each other at drying temperaturesbelow 80C and was equivalent to its original value of the controlsample On the other hand the change in whiteness for Suphanburi 1 was



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Table

1

Gelatinizationproperties

ofrice

flourofSuphanburi1andPathumthani1varieties

Rice

variety

InitialMC

dry

basis

Inletair

temp(C)

Transitiontemp(C)

H

(Jg)a

Degreeof

gelatinization

Tonset

Tpeak

Tconclude

Suphanburi1

325

Control

715

764

814

71

150

781

850

895

32

549

288

Control

712

772

851

67

150

730

781

855

52

223

Pathumthani1

325

Control

615

736

856

74

150

594

752

826

43

419

288

Control

712

772

822

67

150

695

762

818

44

267

Notecontrolfrac14

Rew

ettedrice

whichwasgentlydried

byambientairventilationin

thin-layer

aBasedondry

starchweight



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rather sensitive to initial moisture content with the lowest brightnessbeing for the initial moisture content of 325 dry basis

At a higher temperature of 80C and at lower initial moisturecontent changes in whiteness for both rice varieties were less pro-nounced For paddy samples that had an initial moisture content of250 dry basis The value of whiteness varied between 498 and 513 forSuphanburi 1 and between 441 and 462 for Pathumthani 1 For paddy

(a)

(b)

35

40

45

50

55

40 50 60 70 80 90 100 110 120 130 140 150



Whi

tene

ss

Initial MC 250 dry basis (whiteness after rewetting= 499)



whiteness before rewetting= 529

35

40

45

50

55

40 50 60 70 80 90 100 110 120 130 140 150

Whi

tene

ss (

)





Figure 6 Effect of inlet air temperature on whiteness of Suphanburi 1 and



drying) (a) Suphanburi 1 (b) Pathumthani 1 (View image in color online)



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samples with an initial moisture content of 288 dry basis the values ofwhiteness varied between 503 and 521 for Suphanburi 1 and between447 and 465 for Pathumthani 1 over the drying temperature range of 80to 150C Most of these results indicated that the drying temperaturerange of 40ndash150C along with the low initial moisture contents of ricesamples of 250 and 288 dry basis for both rice varieties did notsignificantly affect the whiteness of rice ( plt 005) However a steepdecrease in whiteness with increasing air temperature for the sampleswith a high initial moisture content of 325 dry basis for both ricevarieties was evident This can be explained by the effects of the longerdrying time and the Maillard nonenzymatic browning reaction[137] Atthis high initial moisture content drying took longer time than thatrequired by the sample that had lower initial moisture contents of 250and 288 dry basis In addition the Maillard browning reaction ratewas accelerated when the drying temperature increased In contrast theirmobility and reactivity inside the paddy samples that had low initialmoisture content were restricted even though the temperature was risenThe resulting browning rate was thus retarded In addition to thelimitation of reactive biological components in seeds the improvedwhiteness of rice samples was also due to the shorter drying time requiredfor samples with lower initial moisture content However for allexperiments the whiteness values were within an acceptable range forthe commercial purpose[13]

(d) Germination of Paddy

Figures 7(a) and 7(b) show respectively the average percentage ofgermination for paddy with three initial moisture contents of 250 288and 325 dry basis for Suphanburi 1 and Pathumthani 1 rice varietiesThe germination of both paddy varieties dried with hot air in thetemperature range of 40ndash60C was in range of 90ndash98 with nosignificant difference between the dried paddy and the control paddy( plt 005) At the drying air temperature of 70C the germination ofpaddy was only found in samples that had initial moisture contents of250 and 288 dry basis however

When an inlet drying air temperature was higher than 80C thedegradation of viability was high and the resulting germination of paddysamples of any initial moisture content did not occur This is due to thefact that the gelatinization of starch granules was partially formedthereby allowing the rice kernel to lose its biological activity in embryoHowever the germination of both paddy varieties dried using inlet drying



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air temperatures below 60C was not significantly changed comparingto its control sample

(e) Chemical Quality of Rice

Based on the determination of the chemical quality of the two ricevarieties it was found that the inlet drying air temperatures of 40ndash150Chad no significant effect on both amylose and protein contents of the

80

85

90

95

100

control 40 50 60 70 80 90 100


Ave

rage

val

ue o

f S

P 1

germ

inat

ion

()




80

85

90

95

100

control 40 50 60 70 80 90 100


Ave

rage

val

ue o

f P

T 1

germ

inat

ion

()




Figure 7 Effect of inlet air temperature on percent germination of Suphanburi 1






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samples the average amylose contents of rice before and after dryingwere in the range of 250 28 and 145 23 (dry weight basis) forSuphanburi 1 and Pathumthani 1 respectively The average value ofprotein content was in the range of 750 005 and 799 005 (dryweight basis) for Suphanburi 1 and Pathumthani 1 respectively

(f) Textural Property of Cooked Rice

Figures 8(a) and 8(b) show the hardness of cooked rice samples driedat different temperatures The hardness of thermally untreated sampleswas 3277 kg for Suphanburi 1 variety and 1639 kg for Pathumthani 1The difference in hardness is attributed to amylose content presented inpaddy When a certain amount of water was added to the sample and therewetted sample was then gently dried the hardness changed in a waythat the samples with higher initial moisture contents had higherhardness except for the range of initial moisture contents between 25and 288 dry basis These changes are attributed to water which acts asplasticizer of the amorphous and partially crystalline starch systems Thissubsequently facilitates the reorganization of the starch crystallites andamylose-lipid complexes to occur and consequently influences thetextural properties of paddy[3637]

As can be seen in Fig 8(a) the hardness of cooked Suphanburi 1 ricesamples at each initial moisture content was insignificantly different fromthat of the control sample ( plt 005) At an initial moisture content of250 dry basis the harness of cooked rice samples was between 34 and37 kg indicating the small variation with the drying air temperature whilethe trend of hardness was different for the samples that had initialmoisture contents of 288 dry basis and 325 dry basis the hardnessvalues ranged between 31 and 40 kg when using drying air temperaturesof 40ndash150C

Similarly as can be seen in Fig 8(b) the hardness of cookedPathumthani 1 sample tended to be related to the initial moisture contentwhilst there was no significant difference among those samples dried atdifferent drying air temperatures ( plt 005) The hardness values ofPathumthani 1 rice sample at 325 dry basis ranging between 19 and24 kg were above those of the samples that had initial moisture contentsof 250 and 288 dry basis which had the values of hardness vary in therange of 18ndash21 kg

The results showed that the hardness of cooked rice increased with anincreased initial moisture content The reasons for these changes might bedue to partial gelatinization of rice kernel and interaction between starchlipid and protein[38]



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(i) Sensory Evaluation

Table 2 shows the hedonic score of an overall acceptability of cookedSuphanburi 1 and Pathumthani 1 rice samples The results show that for

25

30

35

40

45

40 50 60 70 80 90 100 110 120 130 140 150



Har

dnes

s (k

g)

Initial MC 325 dry basis (hardness after rewetting = 3374 kg)



hardness before rewetting = 3277 kg

15

20

25

30

40 50 60 70 80 90 100 110 120 130 140 150

Har

dnes

s (k

g)




hardness before rewetting =1639 kg

(a)

(b)

Figure 8 Effect of inlet air temperature on hardness of Suphanburi 1 and






ORDER REPRINTS

all experiments except Pathumthani 1 with an initial moisture contentof 250 dry basis the overall acceptability was in preference scoresfrom 405 to 554 representing like nor dislike The overall acceptabilityfor Pathumthani 1 with an initial moisture content of 250 dry basiswas in preference scores from 492 to 838 which means like nor disliketo very much like It can be concluded that the inlet drying airtemperature and initial moisture content had an insignificantly changethe overall acceptability of cooked rice comparing to the rewetted rice(control sample)

Table 2 Effect of inlet drying air temperature on overall acceptability of cooked

rice of Suphanburi 1 and Pathumthani 1 varieties

Overall acceptability of cooked rice

Inlet

air temp

(C)

Initial MC Pathumthani 1 Initial MC Suphanburi 1

250

(dry basis)

288

(dry basis)

325

(dry basis)

250

(dry basis)

288

(dry basis)

325

(dry basis)

Control 694b 598a 496b 646a 453a 497a

40 754a 640a 838a 554a 457a 443b

60 721b 544b 792a 517b 455a 505a

80 718b 527b 783a 558a 446a 467a

100 737a 632a 496b 538b 405b 438b

120 752a 582b 663b 463b 405b 467a

140 752a 577b 492b 458b 451a 413b

150 737a 586a 708a 467b 486a 409b

Note The same letter in the same column indicates no significant difference at

plt 005

Controlfrac14Rewetted rice which was gently dried by ambient air ventilation in

thin-layer

The meaning of hedonic score is as follows

Hedonic scale from 1ndash9

1frac14Extremely dislike

2frac14Very much dislike

3frac14Moderately dislike

4frac14 Slightly dislike

5frac14Like nor dislike

6frac14 Slightly like

7frac14Moderately like


9frac14Extremely like



ORDER REPRINTS

CONCLUSIONS

In this study the effect of inlet drying air temperature on various

qualities of rice was experimentally investigated It was found that paddy

either low- and high-amylose content varieties which had initial moisture

contents of 250ndash325 dry basis and was subjected to fluidized bed

drying at temperatures between 40ndash150C could maintain high head rice

yield comparing to the control rice samplesThe head rice yield of Suphanburi 1 samples which have high

amylose content was significantly related to the inlet drying air

temperature and initial moisture content whilst the head rice yield of

Pathumthani 1 samples which have lower amylose content did not tend

to be associated with the inlet drying air temperature as well as the initial

moisture content However it was found that the whiteness of both rice

varieties that had initial moisture contents of 250ndash325 dry basis

slightly decreased with an increase in inlet drying air temperature the

effect was more pronounced at inlet drying air temperatures of over 80C

and the initial moisture content of 325 dry basisThe germination of both paddy varieties dried at inlet drying air

temperatures below 60C was not significantly changed comparing to

their control samples When inlet drying air temperatures were higher

than 80C however germination of paddy samples of any initial

moisture contents did not occur due to partial gelatinization of starch

granules This partial gelatinization at inlet drying air temperatures of

over 90C caused some effects on the morphology endothermic energy of

rice flour hardness and head rice yield of rice samples Moreover the

overall acceptability of both cooked rice samples after drying had an

insignificant correlation with inlet drying air temperature initial moisture

content and rice variety comparing to those of control samples

ACKNOWLDGMENTS

The authors wish to express their sincere thanks to the Thailand

Research Fund (TRF) and the Japan International Research Center for

Agricultural Sciences (JIRCAS) for their financial support and to the

Institute of Food Research and Product Development (IFRPD) of

Kasetsart University Thailand for testing rice qualities and to the

Institute of Technology Rajchamongkrala Headquarter Pathumthani

Thailand for rice whiteness testing



ORDER REPRINTS

REFERENCES

1 Gras PW Banks HJ Bason ML Arriola LP A qualitativestudy of the influences of temperature water activity and storageatmosphere on the yellowing of milled rice J Cereal Science 19899 77ndash89

2 Bason ML Gras PW Banks HJ Esteves LA A qualitativestudy of the influences of temperature water activity and storageatmosphere on the yellowing of paddy endosperm J Cereal Science1990 12 193ndash201

3 Soponronnarit S Srisubati N Yoovidhya T Effect of tempera-ture and relative humidity on yellowing rate of paddy J StoredProd Res 1998 34 (4) 323ndash330

4 Yap AB Juiliano BO Perez CM Artificial yellowing of rice at60C Proceedings Group The Source of Yellow Grains in RiceMyc Centralbl 1988 3 153ndash157

5 Driscoll RH Adamczak T Drying systems for the humid tropicsIn bulk handling and storage of grain in the humid tropics ACIARProceedings 1988 22 58ndash68

6 Poomsa-ad N Soponronnarit S Terdyothin APrachayawarakorn S Head Rice Yield after Drying byFluidization Technique and Tempering Proceedings of the 2ndAsian-Oceania Drying Conference Batu-Feringhai PenangMalaysia Aug 20ndash22 2001

7 Inprasit C Noomhorm N Effect of drying air temperature andgrain temperature of different types of dryer and operation on ricequality Drying Technology 2001 19 (2) 389ndash404

8 Bonazzi C du Peuty MA Themelin A Influence of dryingconditions on the processing quality of rough rice DryingTechnology 1997 15 (3amp4) 1141ndash1157

9 Daniel MJ Marks BP Siebenmorgen TJ Mcnew RWMeullenet JF Effects of long-grain rough rice storage history onend-use quality J Food Sci 1998 63 (5) 832ndash835

10 Soponronnarit S Prachayawarakorn S Optimum strategy forfluidized bed paddy drying Drying Technology 1994 12 (7)1667ndash1686

11 Steffe JF Singh RP Bakshi AS Influence of tempering timeand cooling on rice milling yields and moisture removal Trans ofthe ASAE 1979 22 1214ndash1218 1224

12 Zhang Q Litchfield JB An optimization of intermittent corndrying in a laboratory scale thin layer dryer Drying Technology1991 9 (11) 233ndash244



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13 Soponronnarit S Wetchama S Swasdisevi T Poomsa-ad NManaging moist paddy by drying tempering and ambient airventilation Drying Technology 1999 17 (1amp2) 335ndash344

14 Cnossen AG Jimenez MJ Siebenmorgen TJ Rice fissuringresponse to high drying and tempering temperatures J Food Eng2003 59 61ndash69

15 Poomsa-ad N Soponronnarit S Prachayawarakorn STerdyotin A Effect of tempering on subsequent drying of paddyusing fluidisation technique Drying Technology 2002 20 (1)195ndash210

16 Soponronnarit S Drying in Bulk Storage of High MoistureGrains in the Kingdom of Thailand Final report submitted toAustralian Centre for International Agricultural ResearchCanberra 1987

17 AOAC Official Methods of Analysis Association of OfficialAnalytical Chemists 15th Ed Washington DC USA 1995

18 USDA Grain Grade Procedure Federal Grain Inspection ServiceWashington DC USA 1988

19 Marshall WE Wadsworth JI Verma LR Velupillai LDetermination the degree of gelatinization in parboiled ricecomparison of a subjective and an objective methods CerealChem 1993 70 226ndash230

20 Juliano BO A simplified assay for mill-rice amylose Cereal SciToday 1971 16 334ndash338

21 Kongseree N Training Course in Standardization and Quality ofHoomDokMali Rice Rice Research Station PathumthaniThailand 22ndash24 Dec 1995

22 Tungtrakul P Quality and Physicochemical Properties of RiceRelated to Rice Noodle United Nations University ResearchFellowship Report Tsukuba Japan 1997

23 Cnossen AG Siebenmorgen TJ The glass transition temperatureconcept in rice drying and tempering effect on milling qualityTrans of the ASAE 2000 23 (6) 1661ndash1667

24 Perdon AA Amorphous State Transition in Rice during theDrying Process PhD diss Fayetteville Ark Department of FoodScience University of Arkansas USA 1999

25 Siebenmorgen TJ Perdon AA Applying Glass TransitionPrinciple to Explain Fissure Formation during Drying ProcessPresented in the 1999 Int Starch Tech Conf Urbana June 7ndash91999 Volume III

26 Slade L Levine H A polymer science approach to structureproperty relationships in aqueous food systems non-equilibrium



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behavior of carbohydrate-water systems In Water Relationships inFoods Levine H Slade L Eds Plenum Press New York USA1991 29ndash101

27 Slade L Levine H Glass transitions and water-food structureinteractions Adv Food Nutrit Res 1995 38 103ndash269

28 Kunze OR Fissuring of the rice grain after heated air dryingTrans of the ASAE 1979 22 (5) 1197ndash1202 1207

29 Aquerre R Suarez C Viollaz PE Effect of drying on the qualityof milled rice J of Food Tech 1986 21 75ndash80

30 Eliasson AC Interactions between starch and lipids studied byDSC Thermochimica Acta 1994 246 343ndash356

31 Moritaka S Yasumatsu K Studies on cereals X The effect ofsulfhydryl groups on storage deterioration of milled rice Eiyo ToShokuryo 1972 25 59ndash62

32 Teo CH Abd Karim A Cheah PB Norziah MH SeowCC On the roles of protein and starch in the aging of non-waxy riceflour Food Chem 2000 69 229ndash236

33 Swinkels JJM Starch source chemistry and physics In StarchConversion Technology van Beynum GMA Roels JA EdsMarcel Dekker Inc New York USA 1985 31ndash35

34 Sander JPM Starch manufacturing in the world InAdvanced Post Academic Course on Tapioca Starch TechnologyAIT Center Bangkok Thailand 22ndash26 Jan amp 19ndash23 Feb1996

35 Miah KMA Haque A Douglass MP Clarke B Parboiling ofrice part I effect of hot soaking time on quality of milled rice Int Jof Food Sci and Tech 2002 37 527ndash537

36 Juliano BO Rice Chemistry and Technology 2nd Ed AmericanAssociation of Cereal Chemists Inc St Paul Minnesota USA1985 774

37 Beynum GMA Roels JA Starch Conversion TechnologyMarcel Dekker Inc USA 1985 40ndash41

38 Parnsakhorn S The Effect of Steaming Treatment on AcceleratedAging of Rough Rice ME thesis School of Environment Resourceand Development Asian Institute of Technology BangkokThailand 2001



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DRYING TECHNOLOGY

Vol 22 No 7 pp 1731ndash1754 2004

Effect of Fluidized Bed Drying Temperature on

Various Quality Attributes of Paddy

Supawan Tirawanichakul1 Somkiat Prachayawarakorn2

Warunee Varanyanond3 Patcharee Tungtrakul3 and

Somchart Soponronnarit1

1School of Energy and Materials and2Faculty of Engineering King Mongkutrsquos University of Technology

Thonburi Bangkok Thailand3Institute of Food Research and Product Development Kasetsart

University Bangkean Bangkok Thailand

ABSTRACT

As reported by many researchers it was found that fluidized bed

paddy drying using high drying air temperatures of over 100C

affected the head rice yield and whiteness of dried rice However

only a few studies on fluidized bed paddy drying with drying air

temperatures below 100C were so far reported The main objective

of this work was therefore to study the effect of fluidized bed drying

air temperature on various quality parameters of Suphanburi 1 and

Correspondence Supawan Tirawanichakul School of Energy and Materials

King Mongkutrsquos University of Technology Thonburi Bangkok 10140 Thailand

Fax thorn662-470-8623 E-mail supawanvachiramonhotmailcom

1731

DOI 101081DRT-200025634 0737-3937 (Print) 1532-2300 (Online)

Copyright amp 2004 by Marcel Dekker Inc wwwdekkercom


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maintained


Sensory evaluation

INTRODUCTION





ORDER REPRINTS



EXPERIMENTAL SET-UP




2 Materials




ORDER REPRINTS


2 Methods






ORDER REPRINTS




22 Quality of Rice



Tempering30 minutes





ORDER REPRINTS








Hc

100 eth1THORN










ORDER REPRINTS











ORDER REPRINTS




2 Quality of Rice






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0

2

4

6

8

40 50 60 70 80 90 100 110 120 130 140 150

Ave

rage

dry

ing

rate

(

dry

bas

ism




0

2

4

6

8

40 50 60 70 80 90 100 110 120 130 140 150



Ave

rage

dry

ing

rate

(

dry

bas

ism

in)




(a)

(b)







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40

45

50

55

40 50 60 70 80 90 100 110 120 130 140 150


H

ead

rice

yie

ld





40

45

50

55

60

40 50 60 70 80 90 100 110 120 130 140 150


H

ead

rice

yie

ld





(a)

(b)







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Starch granules







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ORDER REPRINTS

Table

1


ofrice


Rice

variety

InitialMC

dry

basis

Inletair

temp(C)

Transitiontemp(C)

H

(Jg)a

Degreeof

gelatinization

Tonset

Tpeak

Tconclude

Suphanburi1

325

Control

715

764

814

71

150

781

850

895

32

549

288

Control

712

772

851

67

150

730

781

855

52

223

Pathumthani1

325

Control

615

736

856

74

150

594

752

826

43

419

288

Control

712

772

822

67

150

695

762

818

44

267

Notecontrolfrac14

Rew

ettedrice

whichwasgentlydried


thin-layer

aBasedondry

starchweight



ORDER REPRINTS



(a)

(b)

35

40

45

50

55

40 50 60 70 80 90 100 110 120 130 140 150



Whi

tene

ss





35

40

45

50

55

40 50 60 70 80 90 100 110 120 130 140 150

Whi

tene

ss (

)











ORDER REPRINTS







ORDER REPRINTS




80

85

90

95

100

control 40 50 60 70 80 90 100


Ave

rage

val

ue o

f S

P 1

germ

inat

ion

()




80

85

90

95

100

control 40 50 60 70 80 90 100


Ave

rage

val

ue o

f P

T 1

germ

inat

ion

()










ORDER REPRINTS









ORDER REPRINTS



25

30

35

40

45

40 50 60 70 80 90 100 110 120 130 140 150



Har

dnes

s (k

g)





15

20

25

30

40 50 60 70 80 90 100 110 120 130 140 150

Har

dnes

s (k

g)





(a)

(b)







ORDER REPRINTS





Inlet

air temp

(C)


250

(dry basis)

288

(dry basis)

325

(dry basis)

250

(dry basis)

288

(dry basis)

325

(dry basis)

Control 694b 598a 496b 646a 453a 497a

40 754a 640a 838a 554a 457a 443b

60 721b 544b 792a 517b 455a 505a

80 718b 527b 783a 558a 446a 467a

100 737a 632a 496b 538b 405b 438b

120 752a 582b 663b 463b 405b 467a

140 752a 577b 492b 458b 451a 413b

150 737a 586a 708a 467b 486a 409b


plt 005


thin-layer














ORDER REPRINTS

CONCLUSIONS


























ACKNOWLDGMENTS










ORDER REPRINTS

REFERENCES















ORDER REPRINTS

















ORDER REPRINTS

























ORDER REPRINTS




















maintained


Sensory evaluation

INTRODUCTION





ORDER REPRINTS



EXPERIMENTAL SET-UP




2 Materials




ORDER REPRINTS


2 Methods






ORDER REPRINTS




22 Quality of Rice



Tempering30 minutes





ORDER REPRINTS








Hc

100 eth1THORN










ORDER REPRINTS











ORDER REPRINTS




2 Quality of Rice






ORDER REPRINTS


0

2

4

6

8

40 50 60 70 80 90 100 110 120 130 140 150

Ave

rage

dry

ing

rate

(

dry

bas

ism




0

2

4

6

8

40 50 60 70 80 90 100 110 120 130 140 150



Ave

rage

dry

ing

rate

(

dry

bas

ism

in)




(a)

(b)







ORDER REPRINTS



40

45

50

55

40 50 60 70 80 90 100 110 120 130 140 150


H

ead

rice

yie

ld





40

45

50

55

60

40 50 60 70 80 90 100 110 120 130 140 150


H

ead

rice

yie

ld





(a)

(b)







ORDER REPRINTS











































ORDER REPRINTS






Starch granules







ORDER REPRINTS








ORDER REPRINTS

Table

1


ofrice


Rice

variety

InitialMC

dry

basis

Inletair

temp(C)

Transitiontemp(C)

H

(Jg)a

Degreeof

gelatinization

Tonset

Tpeak

Tconclude

Suphanburi1

325

Control

715

764

814

71

150

781

850

895

32

549

288

Control

712

772

851

67

150

730

781

855

52

223

Pathumthani1

325

Control

615

736

856

74

150

594

752

826

43

419

288

Control

712

772

822

67

150

695

762

818

44

267

Notecontrolfrac14

Rew

ettedrice

whichwasgentlydried


thin-layer

aBasedondry

starchweight



ORDER REPRINTS



(a)

(b)

35

40

45

50

55

40 50 60 70 80 90 100 110 120 130 140 150



Whi

tene

ss





35

40

45

50

55

40 50 60 70 80 90 100 110 120 130 140 150

Whi

tene

ss (

)











ORDER REPRINTS







ORDER REPRINTS




80

85

90

95

100

control 40 50 60 70 80 90 100


Ave

rage

val

ue o

f S

P 1

germ

inat

ion

()




80

85

90

95

100

control 40 50 60 70 80 90 100


Ave

rage

val

ue o

f P

T 1

germ

inat

ion

()










ORDER REPRINTS









ORDER REPRINTS



25

30

35

40

45

40 50 60 70 80 90 100 110 120 130 140 150



Har

dnes

s (k

g)





15

20

25

30

40 50 60 70 80 90 100 110 120 130 140 150

Har

dnes

s (k

g)





(a)

(b)







ORDER REPRINTS





Inlet

air temp

(C)


250

(dry basis)

288

(dry basis)

325

(dry basis)

250

(dry basis)

288

(dry basis)

325

(dry basis)

Control 694b 598a 496b 646a 453a 497a

40 754a 640a 838a 554a 457a 443b

60 721b 544b 792a 517b 455a 505a

80 718b 527b 783a 558a 446a 467a

100 737a 632a 496b 538b 405b 438b

120 752a 582b 663b 463b 405b 467a

140 752a 577b 492b 458b 451a 413b

150 737a 586a 708a 467b 486a 409b


plt 005


thin-layer














ORDER REPRINTS

CONCLUSIONS


























ACKNOWLDGMENTS










ORDER REPRINTS

REFERENCES















ORDER REPRINTS

















ORDER REPRINTS

























ORDER REPRINTS



EXPERIMENTAL SET-UP




2 Materials




ORDER REPRINTS


2 Methods






ORDER REPRINTS




22 Quality of Rice



Tempering30 minutes





ORDER REPRINTS








Hc

100 eth1THORN










ORDER REPRINTS











ORDER REPRINTS




2 Quality of Rice






ORDER REPRINTS


0

2

4

6

8

40 50 60 70 80 90 100 110 120 130 140 150

Ave

rage

dry

ing

rate

(

dry

bas

ism




0

2

4

6

8

40 50 60 70 80 90 100 110 120 130 140 150



Ave

rage

dry

ing

rate

(

dry

bas

ism

in)




(a)

(b)







ORDER REPRINTS



40

45

50

55

40 50 60 70 80 90 100 110 120 130 140 150


H

ead

rice

yie

ld





40

45

50

55

60

40 50 60 70 80 90 100 110 120 130 140 150


H

ead

rice

yie

ld





(a)

(b)







ORDER REPRINTS











































ORDER REPRINTS






Starch granules







ORDER REPRINTS








ORDER REPRINTS

Table

1


ofrice


Rice

variety

InitialMC

dry

basis

Inletair

temp(C)

Transitiontemp(C)

H

(Jg)a

Degreeof

gelatinization

Tonset

Tpeak

Tconclude

Suphanburi1

325

Control

715

764

814

71

150

781

850

895

32

549

288

Control

712

772

851

67

150

730

781

855

52

223

Pathumthani1

325

Control

615

736

856

74

150

594

752

826

43

419

288

Control

712

772

822

67

150

695

762

818

44

267

Notecontrolfrac14

Rew

ettedrice

whichwasgentlydried


thin-layer

aBasedondry

starchweight



ORDER REPRINTS



(a)

(b)

35

40

45

50

55

40 50 60 70 80 90 100 110 120 130 140 150



Whi

tene

ss





35

40

45

50

55

40 50 60 70 80 90 100 110 120 130 140 150

Whi

tene

ss (

)











ORDER REPRINTS







ORDER REPRINTS




80

85

90

95

100

control 40 50 60 70 80 90 100


Ave

rage

val

ue o

f S

P 1

germ

inat

ion

()




80

85

90

95

100

control 40 50 60 70 80 90 100


Ave

rage

val

ue o

f P

T 1

germ

inat

ion

()










ORDER REPRINTS









ORDER REPRINTS



25

30

35

40

45

40 50 60 70 80 90 100 110 120 130 140 150



Har

dnes

s (k

g)





15

20

25

30

40 50 60 70 80 90 100 110 120 130 140 150

Har

dnes

s (k

g)





(a)

(b)







ORDER REPRINTS





Inlet

air temp

(C)


250

(dry basis)

288

(dry basis)

325

(dry basis)

250

(dry basis)

288

(dry basis)

325

(dry basis)

Control 694b 598a 496b 646a 453a 497a

40 754a 640a 838a 554a 457a 443b

60 721b 544b 792a 517b 455a 505a

80 718b 527b 783a 558a 446a 467a

100 737a 632a 496b 538b 405b 438b

120 752a 582b 663b 463b 405b 467a

140 752a 577b 492b 458b 451a 413b

150 737a 586a 708a 467b 486a 409b


plt 005


thin-layer














ORDER REPRINTS

CONCLUSIONS


























ACKNOWLDGMENTS










ORDER REPRINTS

REFERENCES















ORDER REPRINTS

















ORDER REPRINTS

























ORDER REPRINTS


2 Methods






ORDER REPRINTS




22 Quality of Rice



Tempering30 minutes





ORDER REPRINTS








Hc

100 eth1THORN










ORDER REPRINTS











ORDER REPRINTS




2 Quality of Rice






ORDER REPRINTS


0

2

4

6

8

40 50 60 70 80 90 100 110 120 130 140 150

Ave

rage

dry

ing

rate

(

dry

bas

ism




0

2

4

6

8

40 50 60 70 80 90 100 110 120 130 140 150



Ave

rage

dry

ing

rate

(

dry

bas

ism

in)




(a)

(b)







ORDER REPRINTS



40

45

50

55

40 50 60 70 80 90 100 110 120 130 140 150


H

ead

rice

yie

ld





40

45

50

55

60

40 50 60 70 80 90 100 110 120 130 140 150


H

ead

rice

yie

ld





(a)

(b)







ORDER REPRINTS











































ORDER REPRINTS






Starch granules







ORDER REPRINTS








ORDER REPRINTS

Table

1


ofrice


Rice

variety

InitialMC

dry

basis

Inletair

temp(C)

Transitiontemp(C)

H

(Jg)a

Degreeof

gelatinization

Tonset

Tpeak

Tconclude

Suphanburi1

325

Control

715

764

814

71

150

781

850

895

32

549

288

Control

712

772

851

67

150

730

781

855

52

223

Pathumthani1

325

Control

615

736

856

74

150

594

752

826

43

419

288

Control

712

772

822

67

150

695

762

818

44

267

Notecontrolfrac14

Rew

ettedrice

whichwasgentlydried


thin-layer

aBasedondry

starchweight



ORDER REPRINTS



(a)

(b)

35

40

45

50

55

40 50 60 70 80 90 100 110 120 130 140 150



Whi

tene

ss





35

40

45

50

55

40 50 60 70 80 90 100 110 120 130 140 150

Whi

tene

ss (

)











ORDER REPRINTS







ORDER REPRINTS




80

85

90

95

100

control 40 50 60 70 80 90 100


Ave

rage

val

ue o

f S

P 1

germ

inat

ion

()




80

85

90

95

100

control 40 50 60 70 80 90 100


Ave

rage

val

ue o

f P

T 1

germ

inat

ion

()










ORDER REPRINTS









ORDER REPRINTS



25

30

35

40

45

40 50 60 70 80 90 100 110 120 130 140 150



Har

dnes

s (k

g)





15

20

25

30

40 50 60 70 80 90 100 110 120 130 140 150

Har

dnes

s (k

g)





(a)

(b)







ORDER REPRINTS





Inlet

air temp

(C)


250

(dry basis)

288

(dry basis)

325

(dry basis)

250

(dry basis)

288

(dry basis)

325

(dry basis)

Control 694b 598a 496b 646a 453a 497a

40 754a 640a 838a 554a 457a 443b

60 721b 544b 792a 517b 455a 505a

80 718b 527b 783a 558a 446a 467a

100 737a 632a 496b 538b 405b 438b

120 752a 582b 663b 463b 405b 467a

140 752a 577b 492b 458b 451a 413b

150 737a 586a 708a 467b 486a 409b


plt 005


thin-layer














ORDER REPRINTS

CONCLUSIONS


























ACKNOWLDGMENTS










ORDER REPRINTS

REFERENCES















ORDER REPRINTS

















ORDER REPRINTS

























ORDER REPRINTS




22 Quality of Rice



Tempering30 minutes





ORDER REPRINTS








Hc

100 eth1THORN










ORDER REPRINTS











ORDER REPRINTS




2 Quality of Rice






ORDER REPRINTS


0

2

4

6

8

40 50 60 70 80 90 100 110 120 130 140 150

Ave

rage

dry

ing

rate

(

dry

bas

ism




0

2

4

6

8

40 50 60 70 80 90 100 110 120 130 140 150



Ave

rage

dry

ing

rate

(

dry

bas

ism

in)




(a)

(b)







ORDER REPRINTS



40

45

50

55

40 50 60 70 80 90 100 110 120 130 140 150


H

ead

rice

yie

ld





40

45

50

55

60

40 50 60 70 80 90 100 110 120 130 140 150


H

ead

rice

yie

ld





(a)

(b)







ORDER REPRINTS











































ORDER REPRINTS






Starch granules







ORDER REPRINTS








ORDER REPRINTS

Table

1


ofrice


Rice

variety

InitialMC

dry

basis

Inletair

temp(C)

Transitiontemp(C)

H

(Jg)a

Degreeof

gelatinization

Tonset

Tpeak

Tconclude

Suphanburi1

325

Control

715

764

814

71

150

781

850

895

32

549

288

Control

712

772

851

67

150

730

781

855

52

223

Pathumthani1

325

Control

615

736

856

74

150

594

752

826

43

419

288

Control

712

772

822

67

150

695

762

818

44

267

Notecontrolfrac14

Rew

ettedrice

whichwasgentlydried


thin-layer

aBasedondry

starchweight



ORDER REPRINTS



(a)

(b)

35

40

45

50

55

40 50 60 70 80 90 100 110 120 130 140 150



Whi

tene

ss





35

40

45

50

55

40 50 60 70 80 90 100 110 120 130 140 150

Whi

tene

ss (

)











ORDER REPRINTS







ORDER REPRINTS




80

85

90

95

100

control 40 50 60 70 80 90 100


Ave

rage

val

ue o

f S

P 1

germ

inat

ion

()




80

85

90

95

100

control 40 50 60 70 80 90 100


Ave

rage

val

ue o

f P

T 1

germ

inat

ion

()










ORDER REPRINTS









ORDER REPRINTS



25

30

35

40

45

40 50 60 70 80 90 100 110 120 130 140 150



Har

dnes

s (k

g)





15

20

25

30

40 50 60 70 80 90 100 110 120 130 140 150

Har

dnes

s (k

g)





(a)

(b)







ORDER REPRINTS





Inlet

air temp

(C)


250

(dry basis)

288

(dry basis)

325

(dry basis)

250

(dry basis)

288

(dry basis)

325

(dry basis)

Control 694b 598a 496b 646a 453a 497a

40 754a 640a 838a 554a 457a 443b

60 721b 544b 792a 517b 455a 505a

80 718b 527b 783a 558a 446a 467a

100 737a 632a 496b 538b 405b 438b

120 752a 582b 663b 463b 405b 467a

140 752a 577b 492b 458b 451a 413b

150 737a 586a 708a 467b 486a 409b


plt 005


thin-layer














ORDER REPRINTS

CONCLUSIONS


























ACKNOWLDGMENTS










ORDER REPRINTS

REFERENCES















ORDER REPRINTS

















ORDER REPRINTS

























ORDER REPRINTS








Hc

100 eth1THORN










ORDER REPRINTS











ORDER REPRINTS




2 Quality of Rice






ORDER REPRINTS


0

2

4

6

8

40 50 60 70 80 90 100 110 120 130 140 150

Ave

rage

dry

ing

rate

(

dry

bas

ism




0

2

4

6

8

40 50 60 70 80 90 100 110 120 130 140 150



Ave

rage

dry

ing

rate

(

dry

bas

ism

in)




(a)

(b)







ORDER REPRINTS



40

45

50

55

40 50 60 70 80 90 100 110 120 130 140 150


H

ead

rice

yie

ld





40

45

50

55

60

40 50 60 70 80 90 100 110 120 130 140 150


H

ead

rice

yie

ld





(a)

(b)







ORDER REPRINTS











































ORDER REPRINTS






Starch granules







ORDER REPRINTS








ORDER REPRINTS

Table

1


ofrice


Rice

variety

InitialMC

dry

basis

Inletair

temp(C)

Transitiontemp(C)

H

(Jg)a

Degreeof

gelatinization

Tonset

Tpeak

Tconclude

Suphanburi1

325

Control

715

764

814

71

150

781

850

895

32

549

288

Control

712

772

851

67

150

730

781

855

52

223

Pathumthani1

325

Control

615

736

856

74

150

594

752

826

43

419

288

Control

712

772

822

67

150

695

762

818

44

267

Notecontrolfrac14

Rew

ettedrice

whichwasgentlydried


thin-layer

aBasedondry

starchweight



ORDER REPRINTS



(a)

(b)

35

40

45

50

55

40 50 60 70 80 90 100 110 120 130 140 150



Whi

tene

ss





35

40

45

50

55

40 50 60 70 80 90 100 110 120 130 140 150

Whi

tene

ss (

)











ORDER REPRINTS







ORDER REPRINTS




80

85

90

95

100

control 40 50 60 70 80 90 100


Ave

rage

val

ue o

f S

P 1

germ

inat

ion

()




80

85

90

95

100

control 40 50 60 70 80 90 100


Ave

rage

val

ue o

f P

T 1

germ

inat

ion

()










ORDER REPRINTS









ORDER REPRINTS



25

30

35

40

45

40 50 60 70 80 90 100 110 120 130 140 150



Har

dnes

s (k

g)





15

20

25

30

40 50 60 70 80 90 100 110 120 130 140 150

Har

dnes

s (k

g)





(a)

(b)







ORDER REPRINTS





Inlet

air temp

(C)


250

(dry basis)

288

(dry basis)

325

(dry basis)

250

(dry basis)

288

(dry basis)

325

(dry basis)

Control 694b 598a 496b 646a 453a 497a

40 754a 640a 838a 554a 457a 443b

60 721b 544b 792a 517b 455a 505a

80 718b 527b 783a 558a 446a 467a

100 737a 632a 496b 538b 405b 438b

120 752a 582b 663b 463b 405b 467a

140 752a 577b 492b 458b 451a 413b

150 737a 586a 708a 467b 486a 409b


plt 005


thin-layer














ORDER REPRINTS

CONCLUSIONS


























ACKNOWLDGMENTS










ORDER REPRINTS

REFERENCES















ORDER REPRINTS

















ORDER REPRINTS

























ORDER REPRINTS











ORDER REPRINTS




2 Quality of Rice






ORDER REPRINTS


0

2

4

6

8

40 50 60 70 80 90 100 110 120 130 140 150

Ave

rage

dry

ing

rate

(

dry

bas

ism




0

2

4

6

8

40 50 60 70 80 90 100 110 120 130 140 150



Ave

rage

dry

ing

rate

(

dry

bas

ism

in)




(a)

(b)







ORDER REPRINTS



40

45

50

55

40 50 60 70 80 90 100 110 120 130 140 150


H

ead

rice

yie

ld





40

45

50

55

60

40 50 60 70 80 90 100 110 120 130 140 150


H

ead

rice

yie

ld





(a)

(b)







ORDER REPRINTS











































ORDER REPRINTS






Starch granules







ORDER REPRINTS








ORDER REPRINTS

Table

1


ofrice


Rice

variety

InitialMC

dry

basis

Inletair

temp(C)

Transitiontemp(C)

H

(Jg)a

Degreeof

gelatinization

Tonset

Tpeak

Tconclude

Suphanburi1

325

Control

715

764

814

71

150

781

850

895

32

549

288

Control

712

772

851

67

150

730

781

855

52

223

Pathumthani1

325

Control

615

736

856

74

150

594

752

826

43

419

288

Control

712

772

822

67

150

695

762

818

44

267

Notecontrolfrac14

Rew

ettedrice

whichwasgentlydried


thin-layer

aBasedondry

starchweight



ORDER REPRINTS



(a)

(b)

35

40

45

50

55

40 50 60 70 80 90 100 110 120 130 140 150



Whi

tene

ss





35

40

45

50

55

40 50 60 70 80 90 100 110 120 130 140 150

Whi

tene

ss (

)











ORDER REPRINTS







ORDER REPRINTS




80

85

90

95

100

control 40 50 60 70 80 90 100


Ave

rage

val

ue o

f S

P 1

germ

inat

ion

()




80

85

90

95

100

control 40 50 60 70 80 90 100


Ave

rage

val

ue o

f P

T 1

germ

inat

ion

()










ORDER REPRINTS









ORDER REPRINTS



25

30

35

40

45

40 50 60 70 80 90 100 110 120 130 140 150



Har

dnes

s (k

g)





15

20

25

30

40 50 60 70 80 90 100 110 120 130 140 150

Har

dnes

s (k

g)





(a)

(b)







ORDER REPRINTS





Inlet

air temp

(C)


250

(dry basis)

288

(dry basis)

325

(dry basis)

250

(dry basis)

288

(dry basis)

325

(dry basis)

Control 694b 598a 496b 646a 453a 497a

40 754a 640a 838a 554a 457a 443b

60 721b 544b 792a 517b 455a 505a

80 718b 527b 783a 558a 446a 467a

100 737a 632a 496b 538b 405b 438b

120 752a 582b 663b 463b 405b 467a

140 752a 577b 492b 458b 451a 413b

150 737a 586a 708a 467b 486a 409b


plt 005


thin-layer














ORDER REPRINTS

CONCLUSIONS


























ACKNOWLDGMENTS










ORDER REPRINTS

REFERENCES















ORDER REPRINTS

















ORDER REPRINTS

























ORDER REPRINTS




2 Quality of Rice






ORDER REPRINTS


0

2

4

6

8

40 50 60 70 80 90 100 110 120 130 140 150

Ave

rage

dry

ing

rate

(

dry

bas

ism




0

2

4

6

8

40 50 60 70 80 90 100 110 120 130 140 150



Ave

rage

dry

ing

rate

(

dry

bas

ism

in)




(a)

(b)







ORDER REPRINTS



40

45

50

55

40 50 60 70 80 90 100 110 120 130 140 150


H

ead

rice

yie

ld





40

45

50

55

60

40 50 60 70 80 90 100 110 120 130 140 150


H

ead

rice

yie

ld





(a)

(b)







ORDER REPRINTS











































ORDER REPRINTS






Starch granules







ORDER REPRINTS








ORDER REPRINTS

Table

1


ofrice


Rice

variety

InitialMC

dry

basis

Inletair

temp(C)

Transitiontemp(C)

H

(Jg)a

Degreeof

gelatinization

Tonset

Tpeak

Tconclude

Suphanburi1

325

Control

715

764

814

71

150

781

850

895

32

549

288

Control

712

772

851

67

150

730

781

855

52

223

Pathumthani1

325

Control

615

736

856

74

150

594

752

826

43

419

288

Control

712

772

822

67

150

695

762

818

44

267

Notecontrolfrac14

Rew

ettedrice

whichwasgentlydried


thin-layer

aBasedondry

starchweight



ORDER REPRINTS



(a)

(b)

35

40

45

50

55

40 50 60 70 80 90 100 110 120 130 140 150



Whi

tene

ss





35

40

45

50

55

40 50 60 70 80 90 100 110 120 130 140 150

Whi

tene

ss (

)











ORDER REPRINTS







ORDER REPRINTS




80

85

90

95

100

control 40 50 60 70 80 90 100


Ave

rage

val

ue o

f S

P 1

germ

inat

ion

()




80

85

90

95

100

control 40 50 60 70 80 90 100


Ave

rage

val

ue o

f P

T 1

germ

inat

ion

()










ORDER REPRINTS









ORDER REPRINTS



25

30

35

40

45

40 50 60 70 80 90 100 110 120 130 140 150



Har

dnes

s (k

g)





15

20

25

30

40 50 60 70 80 90 100 110 120 130 140 150

Har

dnes

s (k

g)





(a)

(b)







ORDER REPRINTS





Inlet

air temp

(C)


250

(dry basis)

288

(dry basis)

325

(dry basis)

250

(dry basis)

288

(dry basis)

325

(dry basis)

Control 694b 598a 496b 646a 453a 497a

40 754a 640a 838a 554a 457a 443b

60 721b 544b 792a 517b 455a 505a

80 718b 527b 783a 558a 446a 467a

100 737a 632a 496b 538b 405b 438b

120 752a 582b 663b 463b 405b 467a

140 752a 577b 492b 458b 451a 413b

150 737a 586a 708a 467b 486a 409b


plt 005


thin-layer














ORDER REPRINTS

CONCLUSIONS


























ACKNOWLDGMENTS










ORDER REPRINTS

REFERENCES















ORDER REPRINTS

















ORDER REPRINTS

























ORDER REPRINTS


0

2

4

6

8

40 50 60 70 80 90 100 110 120 130 140 150

Ave

rage

dry

ing

rate

(

dry

bas

ism




0

2

4

6

8

40 50 60 70 80 90 100 110 120 130 140 150



Ave

rage

dry

ing

rate

(

dry

bas

ism

in)




(a)

(b)







ORDER REPRINTS



40

45

50

55

40 50 60 70 80 90 100 110 120 130 140 150


H

ead

rice

yie

ld





40

45

50

55

60

40 50 60 70 80 90 100 110 120 130 140 150


H

ead

rice

yie

ld





(a)

(b)







ORDER REPRINTS











































ORDER REPRINTS






Starch granules







ORDER REPRINTS








ORDER REPRINTS

Table

1


ofrice


Rice

variety

InitialMC

dry

basis

Inletair

temp(C)

Transitiontemp(C)

H

(Jg)a

Degreeof

gelatinization

Tonset

Tpeak

Tconclude

Suphanburi1

325

Control

715

764

814

71

150

781

850

895

32

549

288

Control

712

772

851

67

150

730

781

855

52

223

Pathumthani1

325

Control

615

736

856

74

150

594

752

826

43

419

288

Control

712

772

822

67

150

695

762

818

44

267

Notecontrolfrac14

Rew

ettedrice

whichwasgentlydried


thin-layer

aBasedondry

starchweight



ORDER REPRINTS



(a)

(b)

35

40

45

50

55

40 50 60 70 80 90 100 110 120 130 140 150



Whi

tene

ss





35

40

45

50

55

40 50 60 70 80 90 100 110 120 130 140 150

Whi

tene

ss (

)











ORDER REPRINTS







ORDER REPRINTS




80

85

90

95

100

control 40 50 60 70 80 90 100


Ave

rage

val

ue o

f S

P 1

germ

inat

ion

()




80

85

90

95

100

control 40 50 60 70 80 90 100


Ave

rage

val

ue o

f P

T 1

germ

inat

ion

()










ORDER REPRINTS









ORDER REPRINTS



25

30

35

40

45

40 50 60 70 80 90 100 110 120 130 140 150



Har

dnes

s (k

g)





15

20

25

30

40 50 60 70 80 90 100 110 120 130 140 150

Har

dnes

s (k

g)





(a)

(b)







ORDER REPRINTS





Inlet

air temp

(C)


250

(dry basis)

288

(dry basis)

325

(dry basis)

250

(dry basis)

288

(dry basis)

325

(dry basis)

Control 694b 598a 496b 646a 453a 497a

40 754a 640a 838a 554a 457a 443b

60 721b 544b 792a 517b 455a 505a

80 718b 527b 783a 558a 446a 467a

100 737a 632a 496b 538b 405b 438b

120 752a 582b 663b 463b 405b 467a

140 752a 577b 492b 458b 451a 413b

150 737a 586a 708a 467b 486a 409b


plt 005


thin-layer














ORDER REPRINTS

CONCLUSIONS


























ACKNOWLDGMENTS










ORDER REPRINTS

REFERENCES















ORDER REPRINTS

















ORDER REPRINTS

























ORDER REPRINTS



40

45

50

55

40 50 60 70 80 90 100 110 120 130 140 150


H

ead

rice

yie

ld





40

45

50

55

60

40 50 60 70 80 90 100 110 120 130 140 150


H

ead

rice

yie

ld





(a)

(b)







ORDER REPRINTS











































ORDER REPRINTS






Starch granules







ORDER REPRINTS








ORDER REPRINTS

Table

1


ofrice


Rice

variety

InitialMC

dry

basis

Inletair

temp(C)

Transitiontemp(C)

H

(Jg)a

Degreeof

gelatinization

Tonset

Tpeak

Tconclude

Suphanburi1

325

Control

715

764

814

71

150

781

850

895

32

549

288

Control

712

772

851

67

150

730

781

855

52

223

Pathumthani1

325

Control

615

736

856

74

150

594

752

826

43

419

288

Control

712

772

822

67

150

695

762

818

44

267

Notecontrolfrac14

Rew

ettedrice

whichwasgentlydried


thin-layer

aBasedondry

starchweight



ORDER REPRINTS



(a)

(b)

35

40

45

50

55

40 50 60 70 80 90 100 110 120 130 140 150



Whi

tene

ss





35

40

45

50

55

40 50 60 70 80 90 100 110 120 130 140 150

Whi

tene

ss (

)











ORDER REPRINTS







ORDER REPRINTS




80

85

90

95

100

control 40 50 60 70 80 90 100


Ave

rage

val

ue o

f S

P 1

germ

inat

ion

()




80

85

90

95

100

control 40 50 60 70 80 90 100


Ave

rage

val

ue o

f P

T 1

germ

inat

ion

()










ORDER REPRINTS









ORDER REPRINTS



25

30

35

40

45

40 50 60 70 80 90 100 110 120 130 140 150



Har

dnes

s (k

g)





15

20

25

30

40 50 60 70 80 90 100 110 120 130 140 150

Har

dnes

s (k

g)





(a)

(b)







ORDER REPRINTS





Inlet

air temp

(C)


250

(dry basis)

288

(dry basis)

325

(dry basis)

250

(dry basis)

288

(dry basis)

325

(dry basis)

Control 694b 598a 496b 646a 453a 497a

40 754a 640a 838a 554a 457a 443b

60 721b 544b 792a 517b 455a 505a

80 718b 527b 783a 558a 446a 467a

100 737a 632a 496b 538b 405b 438b

120 752a 582b 663b 463b 405b 467a

140 752a 577b 492b 458b 451a 413b

150 737a 586a 708a 467b 486a 409b


plt 005


thin-layer














ORDER REPRINTS

CONCLUSIONS


























ACKNOWLDGMENTS










ORDER REPRINTS

REFERENCES















ORDER REPRINTS

















ORDER REPRINTS

























ORDER REPRINTS











































ORDER REPRINTS






Starch granules







ORDER REPRINTS








ORDER REPRINTS

Table

1


ofrice


Rice

variety

InitialMC

dry

basis

Inletair

temp(C)

Transitiontemp(C)

H

(Jg)a

Degreeof

gelatinization

Tonset

Tpeak

Tconclude

Suphanburi1

325

Control

715

764

814

71

150

781

850

895

32

549

288

Control

712

772

851

67

150

730

781

855

52

223

Pathumthani1

325

Control

615

736

856

74

150

594

752

826

43

419

288

Control

712

772

822

67

150

695

762

818

44

267

Notecontrolfrac14

Rew

ettedrice

whichwasgentlydried


thin-layer

aBasedondry

starchweight



ORDER REPRINTS



(a)

(b)

35

40

45

50

55

40 50 60 70 80 90 100 110 120 130 140 150



Whi

tene

ss





35

40

45

50

55

40 50 60 70 80 90 100 110 120 130 140 150

Whi

tene

ss (

)











ORDER REPRINTS







ORDER REPRINTS




80

85

90

95

100

control 40 50 60 70 80 90 100


Ave

rage

val

ue o

f S

P 1

germ

inat

ion

()




80

85

90

95

100

control 40 50 60 70 80 90 100


Ave

rage

val

ue o

f P

T 1

germ

inat

ion

()










ORDER REPRINTS









ORDER REPRINTS



25

30

35

40

45

40 50 60 70 80 90 100 110 120 130 140 150



Har

dnes

s (k

g)





15

20

25

30

40 50 60 70 80 90 100 110 120 130 140 150

Har

dnes

s (k

g)





(a)

(b)







ORDER REPRINTS





Inlet

air temp

(C)


250

(dry basis)

288

(dry basis)

325

(dry basis)

250

(dry basis)

288

(dry basis)

325

(dry basis)

Control 694b 598a 496b 646a 453a 497a

40 754a 640a 838a 554a 457a 443b

60 721b 544b 792a 517b 455a 505a

80 718b 527b 783a 558a 446a 467a

100 737a 632a 496b 538b 405b 438b

120 752a 582b 663b 463b 405b 467a

140 752a 577b 492b 458b 451a 413b

150 737a 586a 708a 467b 486a 409b


plt 005


thin-layer














ORDER REPRINTS

CONCLUSIONS


























ACKNOWLDGMENTS










ORDER REPRINTS

REFERENCES















ORDER REPRINTS

















ORDER REPRINTS

























ORDER REPRINTS






Starch granules







ORDER REPRINTS








ORDER REPRINTS

Table

1


ofrice


Rice

variety

InitialMC

dry

basis

Inletair

temp(C)

Transitiontemp(C)

H

(Jg)a

Degreeof

gelatinization

Tonset

Tpeak

Tconclude

Suphanburi1

325

Control

715

764

814

71

150

781

850

895

32

549

288

Control

712

772

851

67

150

730

781

855

52

223

Pathumthani1

325

Control

615

736

856

74

150

594

752

826

43

419

288

Control

712

772

822

67

150

695

762

818

44

267

Notecontrolfrac14

Rew

ettedrice

whichwasgentlydried


thin-layer

aBasedondry

starchweight



ORDER REPRINTS



(a)

(b)

35

40

45

50

55

40 50 60 70 80 90 100 110 120 130 140 150



Whi

tene

ss





35

40

45

50

55

40 50 60 70 80 90 100 110 120 130 140 150

Whi

tene

ss (

)











ORDER REPRINTS







ORDER REPRINTS




80

85

90

95

100

control 40 50 60 70 80 90 100


Ave

rage

val

ue o

f S

P 1

germ

inat

ion

()




80

85

90

95

100

control 40 50 60 70 80 90 100


Ave

rage

val

ue o

f P

T 1

germ

inat

ion

()










ORDER REPRINTS









ORDER REPRINTS



25

30

35

40

45

40 50 60 70 80 90 100 110 120 130 140 150



Har

dnes

s (k

g)





15

20

25

30

40 50 60 70 80 90 100 110 120 130 140 150

Har

dnes

s (k

g)





(a)

(b)







ORDER REPRINTS





Inlet

air temp

(C)


250

(dry basis)

288

(dry basis)

325

(dry basis)

250

(dry basis)

288

(dry basis)

325

(dry basis)

Control 694b 598a 496b 646a 453a 497a

40 754a 640a 838a 554a 457a 443b

60 721b 544b 792a 517b 455a 505a

80 718b 527b 783a 558a 446a 467a

100 737a 632a 496b 538b 405b 438b

120 752a 582b 663b 463b 405b 467a

140 752a 577b 492b 458b 451a 413b

150 737a 586a 708a 467b 486a 409b


plt 005


thin-layer














ORDER REPRINTS

CONCLUSIONS


























ACKNOWLDGMENTS










ORDER REPRINTS

REFERENCES















ORDER REPRINTS

















ORDER REPRINTS

























ORDER REPRINTS








ORDER REPRINTS

Table

1


ofrice


Rice

variety

InitialMC

dry

basis

Inletair

temp(C)

Transitiontemp(C)

H

(Jg)a

Degreeof

gelatinization

Tonset

Tpeak

Tconclude

Suphanburi1

325

Control

715

764

814

71

150

781

850

895

32

549

288

Control

712

772

851

67

150

730

781

855

52

223

Pathumthani1

325

Control

615

736

856

74

150

594

752

826

43

419

288

Control

712

772

822

67

150

695

762

818

44

267

Notecontrolfrac14

Rew

ettedrice

whichwasgentlydried


thin-layer

aBasedondry

starchweight



ORDER REPRINTS



(a)

(b)

35

40

45

50

55

40 50 60 70 80 90 100 110 120 130 140 150



Whi

tene

ss





35

40

45

50

55

40 50 60 70 80 90 100 110 120 130 140 150

Whi

tene

ss (

)











ORDER REPRINTS







ORDER REPRINTS




80

85

90

95

100

control 40 50 60 70 80 90 100


Ave

rage

val

ue o

f S

P 1

germ

inat

ion

()




80

85

90

95

100

control 40 50 60 70 80 90 100


Ave

rage

val

ue o

f P

T 1

germ

inat

ion

()










ORDER REPRINTS









ORDER REPRINTS



25

30

35

40

45

40 50 60 70 80 90 100 110 120 130 140 150



Har

dnes

s (k

g)





15

20

25

30

40 50 60 70 80 90 100 110 120 130 140 150

Har

dnes

s (k

g)





(a)

(b)







ORDER REPRINTS





Inlet

air temp

(C)


250

(dry basis)

288

(dry basis)

325

(dry basis)

250

(dry basis)

288

(dry basis)

325

(dry basis)

Control 694b 598a 496b 646a 453a 497a

40 754a 640a 838a 554a 457a 443b

60 721b 544b 792a 517b 455a 505a

80 718b 527b 783a 558a 446a 467a

100 737a 632a 496b 538b 405b 438b

120 752a 582b 663b 463b 405b 467a

140 752a 577b 492b 458b 451a 413b

150 737a 586a 708a 467b 486a 409b


plt 005


thin-layer














ORDER REPRINTS

CONCLUSIONS


























ACKNOWLDGMENTS










ORDER REPRINTS

REFERENCES















ORDER REPRINTS

















ORDER REPRINTS

























ORDER REPRINTS

Table

1


ofrice


Rice

variety

InitialMC

dry

basis

Inletair

temp(C)

Transitiontemp(C)

H

(Jg)a

Degreeof

gelatinization

Tonset

Tpeak

Tconclude

Suphanburi1

325

Control

715

764

814

71

150

781

850

895

32

549

288

Control

712

772

851

67

150

730

781

855

52

223

Pathumthani1

325

Control

615

736

856

74

150

594

752

826

43

419

288

Control

712

772

822

67

150

695

762

818

44

267

Notecontrolfrac14

Rew

ettedrice

whichwasgentlydried


thin-layer

aBasedondry

starchweight



ORDER REPRINTS



(a)

(b)

35

40

45

50

55

40 50 60 70 80 90 100 110 120 130 140 150



Whi

tene

ss





35

40

45

50

55

40 50 60 70 80 90 100 110 120 130 140 150

Whi

tene

ss (

)











ORDER REPRINTS







ORDER REPRINTS




80

85

90

95

100

control 40 50 60 70 80 90 100


Ave

rage

val

ue o

f S

P 1

germ

inat

ion

()




80

85

90

95

100

control 40 50 60 70 80 90 100


Ave

rage

val

ue o

f P

T 1

germ

inat

ion

()










ORDER REPRINTS









ORDER REPRINTS



25

30

35

40

45

40 50 60 70 80 90 100 110 120 130 140 150



Har

dnes

s (k

g)





15

20

25

30

40 50 60 70 80 90 100 110 120 130 140 150

Har

dnes

s (k

g)





(a)

(b)







ORDER REPRINTS





Inlet

air temp

(C)


250

(dry basis)

288

(dry basis)

325

(dry basis)

250

(dry basis)

288

(dry basis)

325

(dry basis)

Control 694b 598a 496b 646a 453a 497a

40 754a 640a 838a 554a 457a 443b

60 721b 544b 792a 517b 455a 505a

80 718b 527b 783a 558a 446a 467a

100 737a 632a 496b 538b 405b 438b

120 752a 582b 663b 463b 405b 467a

140 752a 577b 492b 458b 451a 413b

150 737a 586a 708a 467b 486a 409b


plt 005


thin-layer














ORDER REPRINTS

CONCLUSIONS


























ACKNOWLDGMENTS










ORDER REPRINTS

REFERENCES















ORDER REPRINTS

















ORDER REPRINTS

























ORDER REPRINTS



(a)

(b)

35

40

45

50

55

40 50 60 70 80 90 100 110 120 130 140 150



Whi

tene

ss





35

40

45

50

55

40 50 60 70 80 90 100 110 120 130 140 150

Whi

tene

ss (

)











ORDER REPRINTS







ORDER REPRINTS




80

85

90

95

100

control 40 50 60 70 80 90 100


Ave

rage

val

ue o

f S

P 1

germ

inat

ion

()




80

85

90

95

100

control 40 50 60 70 80 90 100


Ave

rage

val

ue o

f P

T 1

germ

inat

ion

()










ORDER REPRINTS









ORDER REPRINTS



25

30

35

40

45

40 50 60 70 80 90 100 110 120 130 140 150



Har

dnes

s (k

g)





15

20

25

30

40 50 60 70 80 90 100 110 120 130 140 150

Har

dnes

s (k

g)





(a)

(b)







ORDER REPRINTS





Inlet

air temp

(C)


250

(dry basis)

288

(dry basis)

325

(dry basis)

250

(dry basis)

288

(dry basis)

325

(dry basis)

Control 694b 598a 496b 646a 453a 497a

40 754a 640a 838a 554a 457a 443b

60 721b 544b 792a 517b 455a 505a

80 718b 527b 783a 558a 446a 467a

100 737a 632a 496b 538b 405b 438b

120 752a 582b 663b 463b 405b 467a

140 752a 577b 492b 458b 451a 413b

150 737a 586a 708a 467b 486a 409b


plt 005


thin-layer














ORDER REPRINTS

CONCLUSIONS


























ACKNOWLDGMENTS










ORDER REPRINTS

REFERENCES















ORDER REPRINTS

















ORDER REPRINTS

























ORDER REPRINTS







ORDER REPRINTS




80

85

90

95

100

control 40 50 60 70 80 90 100


Ave

rage

val

ue o

f S

P 1

germ

inat

ion

()




80

85

90

95

100

control 40 50 60 70 80 90 100


Ave

rage

val

ue o

f P

T 1

germ

inat

ion

()










ORDER REPRINTS









ORDER REPRINTS



25

30

35

40

45

40 50 60 70 80 90 100 110 120 130 140 150



Har

dnes

s (k

g)





15

20

25

30

40 50 60 70 80 90 100 110 120 130 140 150

Har

dnes

s (k

g)





(a)

(b)







ORDER REPRINTS





Inlet

air temp

(C)


250

(dry basis)

288

(dry basis)

325

(dry basis)

250

(dry basis)

288

(dry basis)

325

(dry basis)

Control 694b 598a 496b 646a 453a 497a

40 754a 640a 838a 554a 457a 443b

60 721b 544b 792a 517b 455a 505a

80 718b 527b 783a 558a 446a 467a

100 737a 632a 496b 538b 405b 438b

120 752a 582b 663b 463b 405b 467a

140 752a 577b 492b 458b 451a 413b

150 737a 586a 708a 467b 486a 409b


plt 005


thin-layer














ORDER REPRINTS

CONCLUSIONS


























ACKNOWLDGMENTS










ORDER REPRINTS

REFERENCES















ORDER REPRINTS

















ORDER REPRINTS

























ORDER REPRINTS




80

85

90

95

100

control 40 50 60 70 80 90 100


Ave

rage

val

ue o

f S

P 1

germ

inat

ion

()




80

85

90

95

100

control 40 50 60 70 80 90 100


Ave

rage

val

ue o

f P

T 1

germ

inat

ion

()










ORDER REPRINTS









ORDER REPRINTS



25

30

35

40

45

40 50 60 70 80 90 100 110 120 130 140 150



Har

dnes

s (k

g)





15

20

25

30

40 50 60 70 80 90 100 110 120 130 140 150

Har

dnes

s (k

g)





(a)

(b)







ORDER REPRINTS





Inlet

air temp

(C)


250

(dry basis)

288

(dry basis)

325

(dry basis)

250

(dry basis)

288

(dry basis)

325

(dry basis)

Control 694b 598a 496b 646a 453a 497a

40 754a 640a 838a 554a 457a 443b

60 721b 544b 792a 517b 455a 505a

80 718b 527b 783a 558a 446a 467a

100 737a 632a 496b 538b 405b 438b

120 752a 582b 663b 463b 405b 467a

140 752a 577b 492b 458b 451a 413b

150 737a 586a 708a 467b 486a 409b


plt 005


thin-layer














ORDER REPRINTS

CONCLUSIONS


























ACKNOWLDGMENTS










ORDER REPRINTS

REFERENCES















ORDER REPRINTS

















ORDER REPRINTS

























ORDER REPRINTS









ORDER REPRINTS



25

30

35

40

45

40 50 60 70 80 90 100 110 120 130 140 150



Har

dnes

s (k

g)





15

20

25

30

40 50 60 70 80 90 100 110 120 130 140 150

Har

dnes

s (k

g)





(a)

(b)







ORDER REPRINTS





Inlet

air temp

(C)


250

(dry basis)

288

(dry basis)

325

(dry basis)

250

(dry basis)

288

(dry basis)

325

(dry basis)

Control 694b 598a 496b 646a 453a 497a

40 754a 640a 838a 554a 457a 443b

60 721b 544b 792a 517b 455a 505a

80 718b 527b 783a 558a 446a 467a

100 737a 632a 496b 538b 405b 438b

120 752a 582b 663b 463b 405b 467a

140 752a 577b 492b 458b 451a 413b

150 737a 586a 708a 467b 486a 409b


plt 005


thin-layer














ORDER REPRINTS

CONCLUSIONS


























ACKNOWLDGMENTS










ORDER REPRINTS

REFERENCES















ORDER REPRINTS

















ORDER REPRINTS

























ORDER REPRINTS



25

30

35

40

45

40 50 60 70 80 90 100 110 120 130 140 150



Har

dnes

s (k

g)





15

20

25

30

40 50 60 70 80 90 100 110 120 130 140 150

Har

dnes

s (k

g)





(a)

(b)







ORDER REPRINTS





Inlet

air temp

(C)


250

(dry basis)

288

(dry basis)

325

(dry basis)

250

(dry basis)

288

(dry basis)

325

(dry basis)

Control 694b 598a 496b 646a 453a 497a

40 754a 640a 838a 554a 457a 443b

60 721b 544b 792a 517b 455a 505a

80 718b 527b 783a 558a 446a 467a

100 737a 632a 496b 538b 405b 438b

120 752a 582b 663b 463b 405b 467a

140 752a 577b 492b 458b 451a 413b

150 737a 586a 708a 467b 486a 409b


plt 005


thin-layer














ORDER REPRINTS

CONCLUSIONS


























ACKNOWLDGMENTS










ORDER REPRINTS

REFERENCES















ORDER REPRINTS

















ORDER REPRINTS

























ORDER REPRINTS





Inlet

air temp

(C)


250

(dry basis)

288

(dry basis)

325

(dry basis)

250

(dry basis)

288

(dry basis)

325

(dry basis)

Control 694b 598a 496b 646a 453a 497a

40 754a 640a 838a 554a 457a 443b

60 721b 544b 792a 517b 455a 505a

80 718b 527b 783a 558a 446a 467a

100 737a 632a 496b 538b 405b 438b

120 752a 582b 663b 463b 405b 467a

140 752a 577b 492b 458b 451a 413b

150 737a 586a 708a 467b 486a 409b


plt 005


thin-layer














ORDER REPRINTS

CONCLUSIONS


























ACKNOWLDGMENTS










ORDER REPRINTS

REFERENCES















ORDER REPRINTS

















ORDER REPRINTS

























ORDER REPRINTS

CONCLUSIONS


























ACKNOWLDGMENTS










ORDER REPRINTS

REFERENCES















ORDER REPRINTS

















ORDER REPRINTS

























ORDER REPRINTS

REFERENCES















ORDER REPRINTS

















ORDER REPRINTS

























ORDER REPRINTS

















ORDER REPRINTS

























ORDER REPRINTS


































Date post:	14-Oct-2014
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Effect of Fluidized Bed Drying Temperature on Various Quality Attributes of Paddy

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