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Shelf life prolongation of fruit juices through essential oils and homogenization: a review
A. Bevilacqua, M.R. Corbo, D. Campaniello, D. D'Amato, M. Gallo, B. Speranza and M. Sinigaglia
Department of Food Science, Faculty of Agricultural Science, University of Foggia, via Napoli 25, 71122 Foggia, Italy
This chapter proposes an overview of juice microbiology, then focusing on the effectiveness of essential oils and plant extracts for the inhibition of pathogenic and spoiling microorganisms. Finally, there is a brief overview on juice homogenization, highlighting its benefits and limits for the prolongation of juice shelf life
Keywords fruit juices; shelf life; safety; spoiling microorganisms; natural antimicrobials; alternative approaches
1. General remarks
Codex Alimentarius defines juice as “the fermentable but unfermented juice, intended for direct consumption, obtained by the mechanical process from sound, ripe fruits, preserved exclusively by physical means. The juice must have the characteristic colour, flavour and taste typical of the fruit from which it comes, it may be turbid or clear. The juice may have been concentrated and later reconstituted with water suitable for the purpose of maintaining the essential composition and quality factors of the juice. The addition of sugars or acids can be permitted but must be endorsed in the individual standard” [1]. Juices may be prepared from nearly all fruits, if desired; the most common ones include pineapple, orange, grapefruit, mango and passion fruit. Nevertheless, any fruits (e.g. banana, fig) can be easily pureed, but it is more expensive to produce a clear juice from the pulp. Generally juice is classified as puree, when the resulting consistency is a fluid that pours very slowly, or pulp when it pours even more slowly. Juices can be concentrated for preservation, handling and storage and then reconstituted before consumption. Nectars are made from fruit juices, to which water and sugar have been added; they contain a proscribed minimum of juice, ranging from 25 to 50%. Table 1 reports the classification of different types of drink made from fruits. Flow chart for juice production is simple; a generalized scheme is reported in Appendix I.
Table 1 Designation of different kind of drinks made from fruits [2].
Type Description Pure juice 100% Pure fruit juice with nothing added, not from concentrate From concentrate Made from concentrate, reconstituted and pasteurized Not from concentrate Pasteurized after extraction Chilled, ready to serve Made from concentrate or pasteurized juice, held refrigerated Fresh squeezed Not pasteurized, held refrigerated Fresh frozen Unpasteurized, frozen after extraction Juice blend A mixture of pure juices Puree Pulp-containing, more viscous than juices, totally fruit Nectar Pulpy or clear. Sugar, water and acid added, 25 to 50% juice* Nectar base Possesses sufficient flavour, acid and sugar to require water dilution for consumption* Juice drink Contains 10 to 20% juice* Juice beverage Contains 10 to 20% juice* Juice cocktail Contains 10 to 20% juice* Fruit + ade (e.g. Lemonade) Contains >10% fruit juice, sugar and water* Juice extract Fruit extracted by water, then concentrated*
*Standards for juice solids minimum varies from country to country
2. Juice microflora
Fruit juices contain water, sugars, organic acids, vitamins, and trace elements thus providing an ideal environment for spoilage by microorganisms; on the other hand, they generally have a lower pH (pH<4.5), thus the common feature of their potential spoilage agents is that they must be acid-loving microorganisms. The most commonly encountered microbial genera are Acetobacter, Alicyclobacillus, Bacillus, Clostridium, Gluconobacter, Lactobacillus, Leuconostoc, Saccharobacter, Zymomonas, and Zymobacter. However, yeasts are predominant because of their high acid tolerance
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and the ability of many of them to grow anaerobically. Pichia, Candida, Saccharomyces and Rhodotorula are the genera mainly involved in spoiled juices; the species frequently isolated are Pichia membranifaciens, Candida maltosa, C. sake, Saccharomyces bailii, S. bisphorus, S. cerevisiae, S. rouxii, S. bayanus, Brettanomyces intermedius, Schizosaccharomyces pombe, Torulopsis holmii, Hanseniaspora guilliermondii, Schwanniomyces occidentalis, Dekkera bruxellensis, Torulaspora delbruckii, Zygosaccharomyces microellipsodes, and D. naardenensis. A high level of yeast contamination in fruit juices may be indicative of poor plant hygiene. Most spoilage yeasts are highly fermentative, forming ethanol and CO2 from sugar, causing split cans and cartons, and explosions in glass or plastic bottles (table 2). Amongst the spoilage yeasts, P. membranifaciens is considered as the target microorganism for the optimisation of thermal treatments of juices because it is resistant to heat as well as to moderate amounts of salt, SO2, sorbic, benzoic and acetic acids [3-5]. Acid-tolerant bacteria able to grow in juices include lactic acid (Lactobacillus and Leuconostoc spp.) and acetic acid bacteria (Acetobacter and Gluconobacter spp.), Propionibacterium cyclohexanicum, Bacillus coagulans, B. megaterium, B. macerans, B. polymyxa, B. licheniformis and B. subtilis. Lact. plantarum var. mobilis, Lact. brevis, Leuconostoc mesenteroides and L. dextranicum are known to cause vinegary, buttermilk off-odours and off-flavours in frozen concentrated orange juice; Bacillus species are known to cause flat-sour type spoilage in acidic fruit beverages, because of the production of lactic acid without gas formation (table 2). Lact. plantarum, Lact. brevis and B. coagulans are amongst the most resistant bacteria to thermal treatments [3, 5]. In 1982, a new type of spoilage bacterium emerged in a large scale spoilage incident in Germany, during which flat-sour type spoilage with offensive smelling medicinal or antiseptic characteristics was noted in commercial pasteurised apple juice. The microbe responsible for the incident was a thermo-acidophilic, endospore-forming bacterium, later identified as Alicyclobacillus acidoterrestris [6]. To date, 20 species and 2 subspecies that belong to this genus have been identified and more spoilage incidents have been reported in various fruit juices, fruit juice blends, carbonated fruit juice drinks, fruit pulps and lemonades, with apple juice as the product most often involved [7]. A. acidoterrestris is the species primarily responsible for spoilage incidents, although other species, including A. acidiphilus, A. pomorum, A. hesperidum, A. herbarius, A. cycloheptanicus and A. acidocaldarius have also been implicated due to their ability to produce taint compounds [7]. Most spoilage incidents occurred in spring or summer and spoilage consisted mainly in an off-flavour or –odour production, with or without sediment; sometimes discolouration or cloudiness occurred (table 2). Consumer complaints were often the only reason for companies becoming aware of the problem, since the absence of gas production made spoilage difficult to detect. The off-flavour and -odour detected have been described as medicinal, disinfectant-like, antiseptic, phenolic, smoky and hammy and, in most cases, they have been identified as the chemical compound guaiacol. Although guaiacol seems to be the dominant cause of taint, the halophenols 2,6-dichlorophenol (2,6-DCP) and 2,6-dibromophenol (2,6-DBP) have been also implicated [7, 8]. Additionally, heat resistant species of mycelial fungi such as Byssochlamys fulva, Byssochlamys nivea, Neosartorya fischeri, Talaromyces flavus, Talaromyces macrosporus, Monascus purpureus, Paecilomyces fulvus, Aspergillus versicolor, A. restrictus, and some species of Eupenicillium (E. brefaldianum, E. lapidosum) are reported to spoil fruit juices, pulps and concentrates. Mold growth can result in an off-flavour or odor that may be described as “stale” or “old”, development of a mycelial mat, reduction in sugar content, and mycotoxin production (see table 2) [3, 5].
Table 2 Microorganisms related to spoilage in fruit juices.
Microorganism Spoilage effect Highly fermentative yeasts Production of ethanol and CO2 from sugars, formation of biofilm, bulging or
exploding of containers Acetobacter, Gluconobacter Oxidation of ethanol, fermentation, turbidity Lactobacillus, Leuconostoc Sour or off-taste, buttermilk off-flavour, gummy slime or ropiness, production
of acetic acid, CO2, ethanol Clostridium spp. Production of gas, a strong butyric odor, and increased acidity A. acidoterrestris Phenolic or antiseptic odour or off-flavour with or without light sediment or
slight haze Bacillus spp. Flat sour Zymomonas, Saccharobacter, Zymobacter
Ethanol production
Heat resistant moulds Off-flavour or odour like “stale” or “old”, development of a mycelial mat, reduction in sugar content, mycotoxin production
3. Safety of fruit juices
Numerous serious safety problems associated with fruit juices consumption are documented (table 3) [9, 10]. In the last decade, in North America over 1700 people have fallen ill after consuming juice and cider. Most of these outbreaks
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involved unpasteurized juices such as apple, orange, lemon, pineapple, carrot, coconut, cane sugar, banana, acai and mixed fruit juices. The most common pathogens were Escherichia coli O157:H7 and O111, Salmonella sp., Cryptosporidium and norovirus. A few other outbreaks were due to Vibrio cholerae, Cl. botulinum and yeasts. All reported cases of contamination by pathogenic microorganisms were due to unpasteurized juices, and E. coli is one of the most studied bacteria. Numerous dangerous strains of E. coli exist and are able to produce toxins of various types and toxicities that cause different diseases. The enterohemorrhagic (EHEC) class is of most concern, due to its low infectious dose and its association with hemorrhagic colitis (HC), hemolytic uremic syndrome (HUS), and thrombotic thrombocytopenic purpura (TTP). In 2004 the Center for Disease Control reported an serious outbreak of 213 illnesses associated with apple cider consumption in New York, due to Shiga toxin–producing E. coli O111 together with C. parvum (table 3). The fresh-pressed untreated apple cider was produced at an orchard and sold directly and exclusively to consumers [5, 9]. Salmonella infections are commonly associated with animal-derived foods, such as meat, seafood, dairy, and egg products, rather than juices. However, outbreaks associated with fresh juice have occurred as far back as 1922. Early outbreaks resulting in typhoid fever were associated with poor hygiene by asymptomatic Salmonella Typhi shedding food handlers. As disinfection of water, sanitation procedures, and hygiene practices have improved, outbreaks of typhoid fever have become far less common in developed countries. Nonetheless, given the dramatic increase of fresh fruit imported from developing countries, typhoid fever outbreaks associated with these commodities remain a concern. More recent outbreaks of nontyphoidal salmonellosis in fresh juice have been attributed to fecal-associated contamination of fruit or poor processing practices. In 2005, 152 cases of Salmonella Typhimurium infection associated with commercially distributed unpasteurized orange juice were reported (table 2). Upon inspection, Food and Drug Administration (FDA) found that the production facility did not comply with the HACCP plan and that noncompliance likely contributed to this outbreak [5, 9]. Cryptosporidium parvum is a highly infectious protozoan parasite causing persistent diarrhea. Common reservoirs are ruminants including cattle and sheep. Infection with cryptosporidium does not always result in severe disease symptoms and the organism is far more dangerous for the immunocompromised. Cryptosporidium is more commonly associated with contaminated water; its oocysts are thick-walled, resistant to chlorine, and persistent. Presumably, the thick wall also confers some acid resistance, as outbreaks of cryptosporidiosis have also occurred from fresh-pressed cider. In 2003 a Cryptosporidium parvum outbreak was reported in Ohio with 144 infections associated with commercially distributed apple cider (table 3). The cider was treated with ozone and sold directly to consumers and businesses. Investigation deemed the ozone treatment insufficient to decrease the probability of contamination [5, 9]. In addition to pathogenic bacteria, several new pathogenic yeasts, including C. famata, C. guillermondii, C. krusei, and C. parapsilosis can cause spoilage of fruit juices. These new pathogens are very unlikely to affect healthy individuals but are of concern in immunocompromised patients. Several species of molds are capable of producing different mycotoxins in fruit juices. Mycotoxins, particularly patulin, represent a potent food safety hazard. Some molds, e.g. Penicillium expansum, P. griseofulvum, P. roqueforti var. carneum, P. funiculosum, P. claviforme, P. granulatum, and Byssochlamys spp., produce patulin in apple juice, while others, such as Neosartorya produce fumitremorgins, terrein, verruculogen, and fischerin. Byssochlamys species also produce byssotoxin A and byssochlamic acid. Other mycotoxins produced in fruit juice by molds include ochratoxin A, citrinin, and penicillic acid [3]. Viruses are not very common in fruit juices, even if a serious outbreak from the virus Hepatitis A was recorded in 2004 involving european tourists returned from Egypt (table 2). Finally, although not implicated in foodborne outbreaks associated with fresh juices, another important pathogen is Listeria monocytogenes because its ability to grow at conventional refrigeration temperatures and under acidic conditions. L. monocytogenes is ubiquitous within the environment, carried by animals, and frequently found on fruits. The minimum pH for growth of L. monocytogenes is dependant on the acidulant. For malic acid, one acid found in juices, the lowest pH value for growth of L. monocytogenes is from 4.4 to 4.6 depending on the strain. This pathogen causes listeriosis, a serious disease with complications including meningitis, septicemia and spontaneus abortion in immocompromised individuals and pregnant woman [3, 5].
Table 2 Examples of fruit juice-associated outbreaks, reported by CSPI, from 2000 to 2011 [9, 10].
Year Microorganism N° outbreaks Countries Juice type 2000 Salmonella Enteridis 143 USA Orange 2003 Cryptosporidium parvum 144 Ohio Apple 2004 Escherichia coli O111
and C. parvum 213 New York Apple
2004 Virus Hepatitis A 351 Multiple European countries Orange 2005 Salmonella Tyhimurium 152 Multiple states Orange 2008 Salmonella Panama 33 Netherlands Orange 2010 E. coli O157:H7 7 Maryland and Pennsylvania Apple
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4. Essential oils in juices
Consumer interest towards natural and friendly compounds caused in the past a renewed attention on alternative natural antimicrobial from plant origin, i.e. plant extracts (essential oils, aldehydes, esters), herbs and spices. A brief focus on these antimicrobials is reported in appendix 2. Essential oils (EOs) are aromatic oily liquids, obtained from plant materials (flowers, buds, seeds, leaves, twig bark, herbs, wood, fruits and roots), which can be obtained by fermentation, extraction or distillation [11, 12]. EOs are constituted of a complex mix of various compounds, including terpenes, alcohols, chetones, phenols, acids, aldehydes, and esters [12]; they are referred to as GRAS compounds [13], both as flavouring substances and antimicrobial hurdles against a wide range of microorganisms, including bacteria, yeasts and moulds [14]. Many authors reported on the effectiveness of EOs and their active compounds to inactivate and/or inhibit spoiling and pathogenic microorganisms in juices. Their effects relies upon some main elements: the pH of the product, the kind and the concentration of EO and the microorganism. Concerning pH, it is generally accepted that a low pH improves the action of EOs by increasing their hydrophobicity. Gutierrez et al. [15, 16] found that the antibacterial efficacy of oregano and thyme EOs was very high when pH was 4.33–5.32. However, this general statement was not confirmed for yeasts. Tserennadmid et al. [17] studied the anti-yeast activity of some EOs (clary sage, juniper, lemon and marjoram) and used pH values ranging between 4.0 and 7.0; they found that acididic pHs had only slight effects on the growth of yeasts. Moreover, the inhibitory effect of EOs was maximal at pH 7 but remained good also in the acidic range, thus suggesting that the ionization form of the EO components did not play a major role for the acidophilic yeasts. The storage temperature is another key-factor for the antimicrobial activity of EOs. Friedman et al. [18], in fact, found that the antimicrobial activity of some EOs towards E. coli O157:H7 and Salmonella Hadar inoculated in apple juice was higher at 37°C than at 4 and 21°C, due probably to a higher partition coefficient of oils and to an enhanced fluidity bacterial membrane. Both EOs and active compounds (an active compound is the major componet of an essential oil) have been proposed and used for juice stabilization; some examples are cinnamon, clove, lemon, lemongrass, lime and oregano oils, citrus extract (representative of EOs) and carvacrol, cinnamaldehyde, eugenol, citral geraniol, D-limonene (representative of active compounds of EOs) [14, 19-23]. A brief synopsis of the application of EOs in fruit juices is reported in table 4.
Table 4 Application of EOs in juices
EOs and active compounds Microorganisms Juice Oils and extracts Cinnamon oil Clove oil Citrus extract Lemon oil Lemongrass oil Lime oil Oregano oil Active compounds Carvacrol Cinnamaldehyde Citral Eugenol Geraniol D-limonene
Spoiling bacteria Alicyclobacillus acidoterrestris Bacillus coagulans Lactobacillus plantarum Lact. brevis Pathogens Escherichia coli O157:H7 Listeria monocytogenes Salmonella sp. Yeasts Geotrichum candidum Pichia anomala P. membranifaciens Rhodotorula bacarum Saccharomyces cerevisiae S. bayanus Schizosaccharomyces pombe Moulds Aspergillus spp. Fusarium oxysporum Penicillium spp.
Apple Melon Orange Pear Pineapple Strawberry Tomato Watermelon
A new approach for EOs use in foods was proposed by Donsì et al. [24], who used a nano-encapsulation system (sun flower and palm oils as organic phases; glycerol monooleate, soy lecithin, tween 20 and Cleargum(R) as emulsifying agents) for the entrapment of a mixture of terpenes and D-limonene. They studied the antimicrobial activity of this system towards S. cerevisiae, E. coli and Lact. delbrueckii and found a higher effect of nano-encapsulated compounds in pear and orange juices in preserving the sensorial properties of juices.
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In general, EOs possess a strong antimicrobial activity against spoiling and pathogenic microflora of juices, being the effect greater at low pH; however, the use of some essential oils in fruits juices is not recommended because of their adverse effect on the sensory properties. Therefore, combinations with other preservation methods are required to decrease their impact on food flavour [12].
5. Homogenization and combined approaches
Fruit juices, thanks to their composition, viscosity, and fluidity can be treated successfully through high pressure homogenization (HPH). Samples of orange juice were inoculated with L. innocua ATCC 33090 at a concentration of 7.0 log cfu/ml and pressurised at 300 MPa through the primary homogenizing valve and at 30 MPa on the secondary homogenizing valve [25]. L. innocua viable counts and injured cells were measured periodically after Ultra HPH treatment. Cell counts decreased by approximately 2.5 log units during 18 days. Welti-Chanes et al. [26] evaluated the effect of different HPH treatment (0-250 MPa with a maximum of five passes) on natural microflora of orange juice and found that 5 passes at 100 MPa were required to reduce at 2.93 and 3.27 log cfu/ml mesophilic bacteria and yeasts/moulds, respectively. Saldo et al. [27] applied a HPH processing to apple juice and recovered that a treatment at 200 MPa reduced cell count to the undetectable level. Maresca et al. [28] used a multi-pass HPH treatment (pressure level: 0-250 MPa; number of passes: 1-5) for the pasteurization of orange, red orange, pineapple and Annurca apple juices, thus they found that a 3-pass-HPH treatment at 150 MPa achieved the complete inactivation of S. cerevisiae (previously inoculated in orange, red orange and pineapple juices) as well as the stabilization of endogenous microflora of fresh Annurca apple juice. Patrignani et al. [29, 30] studied the potentialities of HPH (100 MPa for 1-8 passes) to inactivate S. cerevisiae 635 and Zygosaccharomyces bailii, in apricot and carrot juices. Initial inoculum levels of S. cerevisiae were about 3 and 6 log cfu/ml, whereas initial inoculum level of Z. bailii was 5 log cfu/g. They confirmed the significance of the number of passes, pressure level and food matrix on the effectiveness of HPH. HPH treatment was considered a good option for non thermal production of Annurca apple juice by Donsì et al. [31], Who applied homogenization at different pressure levels (150-300 MPa) for the inactivation of endogenous microflora; thus the shelf life of clear juice and juice with pulp could be prolonged for many weeks upon HPH treatment at 250 and 300 MPa. Table 4 proposes a summary of HPH use in juices.
Table 4 Application of HPH in juices
Juice Targets Effect on juice characteristics Apple Carrot Mango Pinepple Orange Tomato
Alicyclobacillus acidoterrestris Escherichia coli O157.H7 Listeria monocytogenes Lactic acid bacteria Saccharomyces cerevisiae Emericella nidulans Fusarium oxysporum Penicillium expansum Aspergillus niger Talaromyces macrosporus
Stabilization of cloudy appearance No effect on pH, color, content of vitamin C and phenols Inhibiton of enzymatic activities
In order to reduce the negative effect on HPH and EOs on food quality, the application of combined hurdles was studied. Hurdle technology is based on the concept of applying a combination of some mild treatments to gradually reduce or inhibit microbial counts, with a better retention of sensory properties and nutritive value than those obtained using only a single process [32] Concerning the combined application of HPH with other treatments, some examples are the papers of Pathanibul et al. [33], Kumar et al. [34], Tribst et al. [35] and Bevilacqua et al. [36]. Pathanibul et al. [33] homogenized apple and carrot juices with high pressure in a range from 0 to 350 MPa in combination with nisin (10 IU/ml) to inactivate E. coli and L. innocua (ca. 7 log cfu/ml); E. coli seemed more sensitive than L. innocua, as a reduction of 5 log cfu/ml was achieved at pressures > 250 MPa. E. coli was also inactivated in apple juice and cider using a combination of seven levels of pressures (from 50 to 350 MPa) and two type of chitosan, regular and water soluble, (0.01 and 0.1%) by Kumar et al. [34]. In particular, HPH induced significant inactivation in the range of 100 to 200 MPa; when HPH treatment was combined with incremental quantities of chitosan (both types), a synergistic effect was observed. These results were more evident in apple juice than apple cider at same homogenizing pressures. Tribst et al. [35] applied HPH and thermal treatment on A. niger conidia inoculated in mango nectar and they concluded that 5.03 minutes of thermal treatment and 300 MPa reduced mould by 5 log cfu/ml, with a synergistic effect. Finally, Bevilacqua et al. [36] studied the combination of citrus extract (0-3 ppm), benzoate (0-300 ppm) and
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homogenization (0-90 MPa) for the inhibition of Pichia membranifaciens; the centroid approach was used to combine the three variables and point out their individual and interactive effects. Thus they found that citrus extract could be a suitable alternative for the inhibition of P. membranifaciens in acidic drinks, as a low amount of this compound (3 ppm) increased the lag phase by 60–70%. In addition, homogenization (90 MPa) was able to reduce significantly the initial cell number.
6. Conclusions and future perspectives
The use of alternative approaches for juice stabilization appears as a promising trend, due to the increased awareness of consumers towards natural, fresh and nutrient-enriched foods. Juices are usually referred as “vitamin containing foods”; therefore, the use of a processing able to retain vitamins and nutrients or minimize their loss could be advisable. However, some issues related to EOs and homogenization should be solved, i.e.:
1.The organoleptic impact of EOs. It would be advisable the use of extracts and/or oils water-soluble, odourless and colourless. 2.The optimization of homogenization and/or combined approaches, in order to make possible a real industrial production (costs, volumes, shelf life duration).
Briefly, why and how use EOs and HPH in juices? Figure 1 could be a possible answer.
PROCESSING GREEN CONSUMERISM
Reduce initial contamination
Control post-processing contamination
Retain or minimize the loss of nutrients. Use friendly compounds
Thermal treat.
Thermal treat.
Thermal treat.
HPH EOs
HPH
HPH
EOs
EOs
SOLUTION. Use a combined approach (HPH+EOs) to:
Reduce the initial contamination
Control post-processing contamination
Retain sensorial and nutritional quality
Figure 1. Why use Essential oils and homogenization in juices? A possible answer. (EOs, essential oils; HPH, homogenization; thermal treat., thermal treatment).
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References
[1] FAO. Fruit Juices and Related Products. Codex Alimentarius. Volume 6; 1992. [2] Bates RP, Morris JR, Crandall PG. Principles and practices of small-and medim –scale fruit juice processing. FAO
Agricultural Services Bulletin. 2001. [3] Vasavada PC. Microbiology of fruit juice and beverages. In: Foster T, Vasavada CP, eds. Beverage quality and safety. Boca
Raton, FL: CRC Press; 2003. [4] Boekhout T, Robert V. Yeasts in food. Beneficial and detrimental aspects. Hamburg: Behr’s Verlag; 2003. [5] Keller SE, Miller AJ. Microbiological safety of fresh citrus and apple juices. In: Sapers GM, Gorny JR, Yousef AE, eds.
Microbiology of fruit and vegetables. Boca Raton, FL: CRC Press Taylor and Francis Group, 2006:211-224. [6] Cerny G, Hennlich W, Poralla K. Fruchtsaftverderb durch Bacillen: Isolierung und Charakterisierung des Verderbserregers.
Zeitschrift für Lebensmittel Untersuchung und Forschung. 1984:179-224. [7] Steyn CE, Cameron M, Witthuhn RC. Occurrence of Alicyclobacillus in the fruit processing environment — A review.
International Journal of Food Microbiology. 2011; 147:1–11. [8] Parish ME. Spoilage of juices and beverages by Alicyclobacillus spp. In: Sapers GM, Gorny JR, Yousef AE, eds.
Microbiology of fruit and vegetables. Boca Raton, FL: CRC Press Taylor and Francis Group, 2006:159-180. [9] Vojdani JD, Beuchat LR, Tauxe RV. Juice-associated outbreaks of human illness in the United States, 1995 through 2005.
Journal of Food Protection. 2008; 71:356–364. [10] Center for Science in the Public Interest, CSPI. Outbreaks and Recalls. Available at
http://www.cspinet.org/foodsafety/outbreak_report.html. Accessed May 5, 2011. [11] Burt S. Essential oils and their antibacterial properties and potential applications in foods-a review. International Journal of
Food Microbiology. 2004; 94:223-253. [12] Raybaudi-Massilia RM, Mosqueda-Melgar J, Soliva-Fortuny R, Martìn-Belloso O. Control of pathogenic and spoilage
microorganisms in fresh-cut fruits and fruit juices by traditional and alternative natural antimicrobials. Comprehensive reviews in food science and food safety. 2009; 8:157-180.
[13] U.S. Food and Drug Administration (USFDA). Food additive status list. Available at http://www.cfsan.fda.goc/dms/rdb/opa-appa.html. Accessed May 5, 2011.
[14] Speranza B, Corbo MR. Essential oils for preserving perishable foods: possibilities and limitations. In. Bevilacqua A, Corbo MR, Sinigaglia M, eds. Application of alternative food-preservation technologies to enhance food-safety and stability. Sharjah UAE: Bentham Publisher, 2010:35-57.
[15] Gutierrez J, Barry-Ryan C, Bourke P. The antimicrobial efficacy of plant essential oil combinations and interactions with food ingredients. International Journal of Food Microbiology. 2008; 124:91-97.
[16] Gutierrez J, Barry-Ryan C, Bourke P. Antimicrobial activity of plant essential oils using food model media: efficacy, synergistic potential and interactions with food components. Food Microbiology. 2009; 26:142-150.
[17] Tserennadmid R, Takò M, Galgòczy L, Pesti M, Vagvölgyi C, Almàssy K, Krisch J. Anti yeast activities of some esential oils in growth medium, fruit juices and milk. International Journal of Food Microbiology. 2011; 144:480-486.
[18] Friedman M, Henika PR, Levin CE, Mandrell RE. Antibacterial activities of plant essential oils and their components against Escherichia coli O157:H7 and Salmonella enterica in apple juice. Journal of Agricultural and Food Chemistry. 2004; 52:6042-6048.
[19] Fisher K, Phillips C. Potential uses of essential oils in food; is citrus the answer. Trends in Food Science and Technology. 2008; 19:156-164.
[20] Bevilacqua A, Corbo MR, Sinigaglia M. In vitro evaluation of the antimicrobial activity of eugenol, limonene and citrus extract against bacteria and yeasts, representative of the spoiling microflora of fruit juices. Journal of Food Protection. 2010; 73:888-894.
[21] Bevilacqua A, Corbo MR, Sinigaglia M. Combining eugenol and cinnamaldehyde to control the growth of Alicyclobacillus acidoterrestris. Food Control. 2010; 21:172-177.
[22] Bevilacqua A, Sinigaglia M, Corbo MR. Use of the surface response methodology and desirability approach to model Alicyclobacillus acidoterrestris spore inactivation. International Journal of Food Science and Technology. 2010; 45:1219-1227.
[23] Campaniello D, Corbo MR, Sinigaglia M. Antifungal activity of eugenol against Penicillium, Aspergillus and Fusarium species. Journal of Food Protection. 2010; 73:1124-1128.
[24] Donsì F, Annunziata M, Sessa M, Ferrari G. Nanoencapsulation of essential oils to enhance their antimicrobial activity. LWT-Food Science and Technology. 2011; doi:10.1016/j.lwt.2011.03.003.
[25] Briñez WJ, Roig-Sagués, AX, Hernández Herrero MM, Guamis López B. Inactivation of Listeria innocua in milk and orange juice by ultra high-pressure homogenization. Journal of Food Protection. 2006; 69:86–92.
[26] Welti-Chanes J, Ochoa-Velasco CE, Guerrero-Beltran JA. High-pressure homogenization of orange juice to inactivate pectinmethylesterase. Innovative Food Science and Emerging Technologies. 2009; 10:457-462.
[27] Saldo J, Suarez-Jacobo A, Gervilla R, Guamis B, Roig-Saguez AX. Use of ultra-high-pressure homogenization to preserve apple juice without heat damage. International Journal of High Pressure Research. 2009; 29:52-56.
[28] Maresca P, Donsì F, Ferrari G. Application of a multi-pass high-pressure homogenization treatment for the pasteurization of fruit juices. Journal of Food Engineering. 2011; 104: 364-372.
[29] Patrignani F, Vannini L, Kamdem SLS, Lanciotti R, Guerzoni ME. Effect of high pressure homogenization on Saccharomyces cerevisiae inactivation and physico-chemical features in apricot and carrot juices. International Journal of Food Microbiology. 2009; 136:26-31.
[30] Patrignani F, Vannini L, Kamdem SLS, Lanciotti R, Guerzoni ME. Potentialities of high-pressure homogenization to inactivate Zygosaccharomyces bailii in fruit juices. Journal of Food Science. 2010; 75:M116-M120.
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[31] Donsì F, Esposito L, Lenza E, Senatore B, Ferrari G. Production of shelf stable Annurca apple juice with pulp by high pressure homogenization. International Journal of Food Engineering. 2009; 5:article 12.
[32] Leistner L. Principles and applications of hurdle technology. In: Gould GW, ed. New methods of food preservation. London: Blackie Academic and Professional, 1994:1-21.
[33] Pathanibul P, Taylor TM, Davidson PM, Harte F. Inactivation of Escherichia coli and Listeria innocua in apple and carrot juices using high pressure homogenization and nisin. International Journal of Food Microbiology. 2009; 129:316-320.
[34] Kumar S, Thippareddi H, Subbiah J, Zivanovic S, Davidson PM, Harte F. Inactivation of Escherichia coli K-12 in apple juice using combination of high-pressure homogenization and chitosan. Journal of Food Science. 2009; 78:M8-M14.
[35] Tribst AAL, Franchi MA, de Massaguer PR, Cristianini M. Quality of mango nectar processed by high-pressure homogenization with optimized heat treatment. Journal of Food Science. 2011; 76:M106-M110.
[36] Bevilacqua A, Corbo MR, Sinigaglia M. Inhibition of Pichia membranifaciens by homogenization and antimicrobials. Food and Bioprocess Technology. 2010; doi: 10.1007/s11947-010-0450-1.
1164 ©FORMATEX 2011
Science against microbial pathogens: communicating current research and technological advances A. Méndez-Vilas (Ed.)______________________________________________________________________________
AP
PE
ND
IX 1
Jui
ce p
rodu
ctio
n
Sta
ge in
pro
cess
Q
ual
ity
Ass
uran
ce
Met
hod
s
Har
vest
frui
t
Che
ck f
or f
ull m
atur
ity.
Sel
ect m
atur
e, u
ndam
aged
fru
its. A
ny f
ruits
that
are
mou
ldy
or u
nder
-ri
pe s
houl
d be
sor
ted
and
rem
oved
.
Was
h
N
eces
sary
to r
emov
e st
ones
, lea
ves
and
soil
. T
he s
elec
ted
frui
ts a
re w
ashe
d in
a tr
ough
usi
ng p
otab
le w
ater
.
So
rt /
grad
e
Insp
ectio
n an
d re
mov
al o
f un
soun
d fr
uit i
s ve
ry im
port
ant,
beca
use
afte
r ju
icin
g on
e pi
ece
of d
efec
tive
fru
it c
an e
nd u
p co
ntam
inat
ing
an e
ntir
e lo
t of
juic
e.
Insp
ectio
n ca
n be
man
ual,
cont
inge
nt u
pon
wor
kers
obs
ervi
ng a
nd
rem
ovin
g de
fect
s or
aut
omat
ic, e
ffec
ted
by c
ompu
ter
cont
rolle
d se
nsor
s to
det
ect o
ff c
olou
r, s
hape
or
size
.
Cut
/slic
e/co
re
Nec
essa
ry to
pee
l the
fru
it a
nd r
emov
e st
ones
or
seed
s. I
f ne
cess
ary,
cho
p th
e fr
uit i
nto
piec
es th
at w
ill f
it in
to th
e liq
uidi
ser
or p
ulpe
r.
Thi
s st
age
is n
eces
sary
for
som
e ty
pe o
f fr
uit (
e.g.
pin
eapp
le).
The
fru
its
are
peel
ed, c
ored
and
des
eed
man
uall
y or
with
aut
omat
ic m
achi
ne,
depe
ndin
g on
the
scal
e of
ope
ratio
n.
Ju
ice
extr
acti
on
It is
ess
entia
l to
wor
k qu
ickl
y be
twee
n th
e ex
trac
tion
of th
e ju
ice
and
the
bottl
ing
stag
e. E
xtra
cted
fru
it ju
ice
that
is le
ft to
st
and
in th
e he
at w
ill s
tart
to f
erm
ent a
nd m
ay s
tart
to
disc
olou
r du
e to
enz
yme
activ
ity.
The
re a
re s
ever
al m
etho
ds to
ext
ract
juic
e de
pend
ing
on th
e ty
pe o
f fr
uit
you
use.
App
les
are
pres
sed,
whe
reas
mel
on a
nd p
apay
a ar
e st
eam
ed to
re
leas
e th
e ju
ice.
Pul
per
is u
sed
for
pine
appl
es, m
ango
, str
awbe
rry
and
othe
r fl
eshi
ng f
ruits
.
Filt
er/c
lari
ficat
ion
of ju
ice
Che
ck th
e pr
oduc
tion
of a
cle
ar o
r br
illia
ntly
cle
ar ju
ice
and
the
prev
entio
n of
pos
t filt
ratio
n tu
rbid
ity.
Rap
id m
etho
ds s
uch
as c
entr
ifug
atio
n an
d fi
ltra
tion
can
pro
duce
a c
lear
ju
ice.
Jui
ces
whe
re a
clo
ud is
des
ired
gen
eral
ly d
o no
t req
uire
filt
ratio
n;
cent
rifu
gatio
n is
ade
quat
e. S
omet
imes
may
be
nece
ssar
y to
use
pec
tic
enzy
mes
to b
reak
dow
n th
e pe
ctin
and
to h
elp
clea
r th
e ju
ice.
Dea
erat
ion
Che
ck th
e le
vels
of
diss
olve
d ox
ygen
. Cle
arly
, onc
e ai
r is
re
mov
ed o
r re
plac
ed b
y in
ert g
as, t
he ju
ice
mus
t be
prot
ecte
d fr
om th
e at
mos
pher
e in
all
subs
eque
nt p
roce
ssin
g st
eps.
Dea
erat
ion
can
be a
ccom
plis
hed
by e
ithe
r fl
ashi
ng th
e he
ated
juic
e in
to
a va
cuum
cha
mbe
r or
sat
urat
ing
the
juic
e w
ith a
n in
ert g
as. N
itrog
en o
r ca
rbon
dio
xide
is b
ubbl
ed th
roug
h th
e ju
ice
prio
r to
sto
ring
und
er a
n in
ert a
tmos
pher
e.
F
ill a
nd s
eal
C
heck
fill
-wei
ght a
nd c
orre
ctly
sea
led
pack
. T
he m
ixed
juic
e is
bot
tled
and
cork
ed, e
ither
man
ually
or
with
au
tom
atic
bot
tle f
illin
g m
achi
ne, d
epen
ding
on
the
scal
e of
ope
ratio
n.
H
eat
H
eat
It is
nec
essa
ry to
des
troy
enz
ymes
and
mic
roor
gani
sms.
The
te
mpe
ratu
re a
nd ti
me
of h
eatin
g ar
e cr
itic
al f
or a
chie
ving
bot
h th
e co
rrec
t she
lf li
fe o
f th
e dr
ink
and
reta
inin
g a
good
col
our
and
flav
our.
If T
etra
bri
ck is
to b
e us
ed f
or p
acka
ging
the
juic
e, b
ulk
past
euri
zatio
n w
ould
be
done
bef
ore
the
pack
agin
g.
Alte
rnat
ivel
y, th
e bo
ttled
juic
e is
pas
teur
ized
at a
pre
dete
rmin
ed
tem
pera
ture
and
tim
e us
ing
a pa
steu
rize
r.
Hot
filli
ng in
to
bottl
es
The
cor
rect
wei
ght s
houl
d be
fill
ed in
to th
e pa
ckag
es e
ach
tim
e.
Tet
ra b
rick
pac
kage
s ca
n al
so b
e us
ed. T
he p
rodu
cts
shou
ld b
e ho
t-fi
lled
into
cle
an, s
teri
lized
bot
tles.
Coo
l, la
bel a
nd s
tore
C
heck
the
labe
l and
sto
rage
con
ditio
ns a
re c
orre
ct.
The
pas
teur
ized
juic
e is
all
owed
to c
ool a
nd th
en a
rran
ged
in c
orru
gate
d ca
rton
s an
d se
aled
.
1165©FORMATEX 2011
Science against microbial pathogens: communicating current research and technological advances A. Méndez-Vilas (Ed.)_______________________________________________________________________________
APPENDIX 2 Alternative natural antimicrobials from plant origin Antimicrobials Definition/details Essential oils (EOs) Aromatic oily liquids obtained from plant material by fermentation,
extraction or distillation. They are a mixture of many compounds, some of them labelled as "major component", the other present as traces. The majority of EOs are regarded as GRAS component
Active compounds Major component of EOS; some examples are eugenol, cinnamaldehyde, thymol, carvacrol, menthol. Generally, they possess a phenolic structure.
Aldehydes and esters Aldehydes are dominant compounds released by plant tissue through the lipoxygenase pathway after some damage. Some examples of aldehydes showing an antimicrobial effect are hexenal, trans-2-hexenal and hexyl-acetate. Vanillin is included in aldehyde groups; although it is regarded as GRAS compound, its use as antimicrobial in juice is limited by the fact that some microorganisms, like A. acidoterrestris, are able to catabolize vanillin for the production of guaiacol (responsible of a severe off-flavour in juices).
Herbs and spices There are few data on the use of herbs and spice in juices as antimicrobial compounds; some example are mint and cinnamon powder.
1166 ©FORMATEX 2011
Science against microbial pathogens: communicating current research and technological advances A. Méndez-Vilas (Ed.)______________________________________________________________________________