Journal of Pharmaceutical and Biological Sciences ISSN: 2320-1924; CODEN: JPBSEV Published by Atom and Cell Publishers © All Rights Reserved Available online at: http://www.jpabs.org/ Review Article Role of organic acids and hydrogen peroxide in fruit juice preservation: A review P. Saranraj1* and M. Ramya2 1 Assistant Professor of Microbiology, Department of Biochemistry, Sacred Heart College (Autonomous), Tirupattur – 635 601, Tamil Nadu, India. 2 Department of Biochemistry, Sacred Heart College (Autonomous), Tirupattur – 635 601, Tamil Nadu, India. Received: 12-01-2016 / Revised Accepted: 19-02-2016 / Published: 03-03-2016 ABSTRACT Fruits contain high levels of sugars and other nutrients and they possess an ideal water activity for microbial growth. Their low pH makes them particularly susceptible to fungal spoilage because a big part of the bacterial competition was eliminated since most bacteria prefer near neutral pH. Some fungi are plant pathogens and can start the spoilage from the field while others, although they could contaminate the fruits in the field, actually proliferate and cause substantial spoilage only after harvest when the main plant defenses are reduced or eliminated. In this present review, we clearly explained the role of organic acids and hydrogen peroxide in fruit juice preservation. The topics covered in this present review are: Microbial spoilage of fruits and fruit products, Sources of contamination of fruit juices, Fruit juice composition, Organic acids in fruit juice preservation, Hydrogen peroxide in fruit juice preservation and Control of microbial spoilage in fruit juices. Key words: Fruit juice, Microbial spoilage, Organic acids, Hydrogen peroxide and Preservation. INTRODUCTION Fresh, unpasteurized fruit juices hold a favorable appeal too many consumers due to their distinct flavor characteristics and perceived nutritional superiority. Producers of unpasteurized juice have traditionally relied upon a juices inherent acidity to render their product microbiologically safe. However, documented outbreaks of Salmonella and Escherichia coli associated with unpasteurized juices have dispelled this belief. As early as 1922 and 1944, outbreaks of typhoid fever have been linked to sweet cider and orange juice consumption. In 1980, before recognition of Escherichia coli as a human pathogen, an outbreak of hemolytic uremic syndrome, likely from Escherichia coli was reported in apple cider [1]. Sixty six cases of Escherichia coli infection, including the death of a child resulted from a 1996 outbreak of Escherichia coli in unpasteurized apple cider [2]. Fruits are vital to our health and well being, as they are furnished with essential vitamins, minerals, fibres and other health-promoting phyotochemical. The present health-conscious generation prefers a diet exhibiting low calories and low fat/sodium contents. A great importance of intake of fruits everyday has been found to half the risk of developing cancer and also reduce the risk of heart disease, diabetes, stroke, obesity, birth defects, cataract, osteoporosis and many more to count [3]. Contamination could arise from fecal contact, but also other sources. Fecal contamination from the use of dropped, unwashed apples has been implicated as the source of Escherichia coli in some apple cider outbreaks [4]. However, vectors such as birds and insects could potentially deposit this pathogen on tree-bound fruit [5]. In a 1995 outbreak of Salmonellosis from unpasterurized orange juice, Salmonella spp. was isolated from amphibians around the processing facility [6]. The fruits differ from vegetables in having somewhat less water but more carbohydrate. The protein, fat and ash content of fruits are respectively, 0.9 % and 0.5 % somewhat lower than vegetables except for ash content. Fruits contain vitamins and other organic compounds, just as vegetables do. On the basis of nutrient content, *Corresponding Author Address: P. Saranraj, Assistant Professor of Microbiology, Department of Biochemistry, Sacred Heart College (Autonomous), Tirupattur – 635 601, Tamil Nadu, India; E.mail: microsaranraj@gmail.com Saranraj and Ramya, J Pharm Biol Sci 2016; 4(2): 58-73 these products would appear to be capable of supporting the growth of bacteria, yeasts and molds. However, the pH of fruits is below the level that generally favors bacteria growth. This one fact alone would seem to be sufficient to explain the general absence of bacteria in the incipient spoilage of fruits [7]. As natural components of fruits, organic acids such as malic acid, citric acid and tartaric acid lower the pH, and help maintain the proper sugar/acid balance in fruit juices [8]. In broth systems, their bacteriostatic and bactericidal effects have been evaluated for both Escherichia coli and Salmonella [9] with pH and degree of dissociation being major factors in a particular acids efficacy. Undissociated acids are more cell permeable, and upon entering the cell can dissociate and lower intracellular pH [10]. Thus, organic acids can affect both the intercellular and extracellular pH. As a natural method of lowering juice pH, increasing the organic acid concentration of juices may improve the antimicrobial efficacy of hydrogen peroxide treatments. have increased in worldwide. Changes in agronomic, harvesting, distribution, processing and consumption patterns, and practices have undoubtedly contributed to this increase [17]. Microorganisms form part of the epiphytic flora of fruits and vegetables and many will be present at the time of consumption. The majority of bacteria found on the surface of plants was usually Gram negative and belong either to the Pseudomonas group or to the bacteria belongs to the family Enterobacteriaceae [18]. Many of these organisms are normally non-pathogenic for humans. The numbers of bacteria present will vary depending on seasonal and climatic variation and may range from 104 to 108 per gram. The inner tissues of fruits are usually regarded as sterile. However, bacteria can be present in low numbers as a result of the uptake of water through certain irrigation or washing procedures. If these waters are contaminated with human pathogens these may also be introduced. About two thirds of the spoilage of fruits was caused by fungal moulds [19]. Members of the genera Penicillium, Aspergillus, Sclerotinia, Botrytis and Rhizopus are well commonly involved in this process. The spoilage was usually associated with cellulolytic or pectinolytic activity which causes softening and weakening of plant structures. These structures are important barriers to prevent growth in the products by contaminating microbes. The survival or growth of contaminating microorganisms was affected by intrinsic, extrinsic and processing factors. Factors of importance are nutrient composition, pH, presence of scales and fibres, redox potential, temperature and gaseous atmosphere. Mechanical shredding, cutting and slicing of the produce open the plant surfaces to microbial attack. The bactericidal efficacy of hydrogen peroxide has been demonstrated in both water and food systems [11] with Gram negative organisms having the most susceptibility [12]. It has been effective in extending the shelf life of cantaloupe, mushrooms, bell peppers, grapes and raisins [13]. This antimicrobial action stems from its ability to form reactive oxygen species such as the hydroxyl radical and singlet oxygen, which can damage DNA and membrane constituents [14]. Hydrogen peroxide has GRAS (Generally Regarded as Safe) status and is currently allowed as an antimicrobial in starch processing and in milk for cheese manufacturing. Sensory changes as a result of hydrogen peroxide and organic acid additions are an important consideration. By contributing a sour or acidic taste, organic acids are only practical in concentrations that do not adversely upset the sugar/acid ratio. Fruit juices are sensitive to oxygen in terms of stability, appearance and flavor. In fact, the color of apple juice is almost solely derived from oxidative reactions with phenolic constituents [15]. The use of hydrogen peroxide for extending the shelf life of strawberries and raspberries was negated due to anthocyanin bleaching [16]. Thus, hydrogen peroxide, as both an oxidative molecule and liberator of oxygen upon degradation, may adversely affect sensory qualities of fruit juice. Fruit juices has been identified as the vehicle of transmission in at least 11 microbial disease outbreaks since 1944, including Typhoid fever in 1944, Hepatitis A Virus in 1962, Viral gastroenteritis in 1966, Typhoid fever in 1989, Enterotoxigenic E. coli in 1992, Salmonella enterica serotype and the largest Salmonella outbreak with fresh orange juice, Salmonella serotype [20]. In 2000, a Salmonella enteritidis outbreak caused by unpasteurized orange juice resulted in 88 illnesses in 6 of the western United States [21]. Acidic fruit juices have also been implicated in outbreaks of gastroenteritis. Unpasteurized apple cider and apple juice were associated with outbreaks of Salmonella typhimurium, Escherichia coli [22], post diarrheal haemolytic uremic syndrome and cryptosporidiosis. The Food and Drug Administration (FDA) issued a final rule to increase the safety of fruits and vegetable juice and juice products [23]. According MICROBIAL SPOILAGE OF FRUITS AND FRUIT PRODUCTS In the past decade, outbreaks of human illness associated with the consumption of raw fruits or unpasteurized fruit products produced from them 59 Saranraj and Ramya, J Pharm Biol Sci 2016; 4(2): 58-73 to this rule, juice processors must use Hazard analysis and critical control point (HACCP) principles for processing and utilize control measures to achieve a 5 log (100000 fold) reduction in the numbers of the most resistant pathogen in their finished products compared to levels that might be present in untreated juice. The rule, effective January 22, 2002, states that approved alternative technologies to pasteurization can be used to achieve microbial reduction. interface creates a slight vacuum due to the decreased partial vapor pressure at the fruit surface, thus potentially sucking bacteria beneath the skin, calyx, or stem scar. Employing such a mechanism, it is reasonable to assume that warm fruit, still on the tree, could internalize pathogens from bird feces, if subjected to a cool rain. Bacterial soft rot in fruit has also been associated with increased levels of Salmonella contamination. Wells and Butterfield [34] reported that Salmonella contamination was present in at least 18 – 20 % of soft rotted samples, compared to 9 -10 % in healthy samples. In addition, fruits disks inoculated with Erwinia carotovora (soft rot bacterium) and Salmonella typhimurium supported 10 times the Salmonella typhimurium levels of fruit disks inoculated with Salmonella typhimurium alone. SOURCES OF CONTAMINATION OF FRUIT JUICES Human pathogens are carried by an array of animate vectors. Animals such as deer and cattle are reservoirs for Escherichia coli [24]. Birds and insects have also been implicated as carriers of this pathogen [25]. Salmonella is harbored by a number of domestic animals as well as humans [26]. Investigations into a 1995 outbreak of Salmonellosis in orange juice isolated the pathogen from frogs and toads around the processing facility [27]. JUICE COMPOSITION Fruit juice is mainly the liquid expressed from fruit cell vacuoles, but also includes insoluble particles and bits of fruit tissue. Though primarily water, this organic medley contains sugars such as glucose, fructose, and sucrose, organic acids (malic, citric, and tartaric), fats, proteins, various volatile compounds and vitamins [35]. Taste and flavor qualities are formed by the sugars, organic acids and aroma compounds present in juice. Sugars and organic acids make up the bulk of the soluble solids fraction, and a proper balance between the concentrations of both are important in the palatability of the juice. Thus, organic acid additions are only reasonable within the scope of maintaining an acceptable sugar/acid ratio. Aroma arises from a number of volatile compounds whose composition was essential to juice quality yet very sensitive to processing techniques. Aroma profile modification is of great importance when considering processing methods for juice manufacturing [36]. Pathogen contamination may occur via contact with the feces of these vectors. Wind fallen or dropped fruit, having a greater likelihood of fecal contamination has been implicated as a pathogen source in recent Escherichia coli outbreaks from cider [28]. Under such circumstances, typical brushing and washing techniques may remove surface fecal contamination, but these techniques become less effective if pathogens are internalized. Though, the mechanisms by which pathogens enter fruit are still questionable, internalization can occur. External injuries such as cuts and abrasions would offer easy attachment and access. Liao and Sapers [29] found that the apple disks with no skin retained 13 – 19 % more Salmonella Chester than disks with skin, indicating easier attachment to abraded or wounded fruit. Natural structures such as the stem, stem scar and calyx are also potential sites for internalization. Of those Salmonella Chester attached to apples after artificial inoculation, 94 % were located on the stem or calyx region [30]. Enzymes released during juice expression cause a host of chemical changes, some of which may detract from the appearance and stability of a juice product. In the case of apple juice under aerobic conditions, polyphenol oxidase catalyzes the polymerization of phenolic constituents which leads to brown coloration (melanin) [37]. In addition to being the sole production of color, these oxidative polymerizations can change the flavor and aroma of the juice. Thus, addition of an oxidant such as hydrogen peroxide would likely have a noted effect on the color, flavor, and aroma of apple juice. In orange juice, pectin methyl esterase converts pectin to pectic acid with the end result being cloud loss and juice separation [38]. Such changes are obvious in unpasteurized orange juice, Wash water quality and temperature may also play a role. Zhuang et al. [31] found that tomatoes at 25 ° C dipped in a 10 °C cell suspension of Salmonella montevideo internalized a significant number of the pathogen. Similar uptake of Escherichia coli was witnessed in apples dipped in cold peptone water [32]. Studies by the FDA using dyed water indicate that microorganisms could potentially be internalized simply through the skin of undamaged fruit, when contacting aqueous suspensions of lower temperature [33]. A warm fruit, cool water 60 Saranraj and Ramya, J Pharm Biol Sci 2016; 4(2): 58-73 which has had no heat treatment to inactivate pectin methyl esterase. acidified with between 0 and 3 % malic and citric acid respectively, were analyzed for the survival of Listeria monocytogenes. Untreated apple cider reduced Listeria monocytogenes to undetectable levels within 48 hours, but orange juice with 3 % citric acid took at least 4 days to have the same effect, and significant numbers survived at least 10 days in untreated orange juice. For Escherichia coli, inactivation in acidified Tryptic Soy Broth (TSB) and agar was demonstrated for citric, malic and tartaric acids [47]. In one study, survival of Escherichia coli was greater in acidified apple juice compared to acidified TSB, suggesting a protective effect of juice constituents. However, contrary to other studies, acidified apple juice enhanced survival compared to untreated apple juice, suggesting a protective effect from the acid under refrigeration [48]. As mentioned, the characteristic brown color of apple juice is a result of oxidative reactions after juice extraction. However, orange and grape juice color is derived from pigments initially present in the fruit. Orange juice derives its color from carotenoids such as β –cryptoxanthin, antheraxathin, α–carotene, β-carotene, and leutin within the juice vesicles. These color components are rather stable to processing, but vary in intensity according to the fruit’s growing season [39]. In purple grape juice, color comes from anthocyanins and phenolic components mostly in the skin of the grape, but must be extracted into the initially clear juice. For wine production, fermentation aids in color extraction, but in juice production, heat is used to extract color components from the skins [40]. Citric acid [HOOC-CH2-COH(COOH)-CH2COOH] is one of the more widely used food acidulants. It is a common constituent of fruits, namely citrus fruits and imparts a pleasant sour taste. Citric acid was commonly employed as an acidulant in canned vegetables and dairy products [49]. In skim milk, citric acid was the most potent inhibitor of Salmonella typhimurium compared to lactic acid and HCl [50]. Fischer et al. [51] reported a 0.75 % solution of citric acid to sufficiently reduce Salmonella typhimurium, Yersinia enterocolitica, Escherichia coli and Staphylococcus aureus on hard-boiled eggs. Under good manufacturing practices, citric acid was approved as a GRAS substance. ORGANIC ACIDS Organic acids occur throughout nature and are used extensively in food systems. In addition to their use as microbial inhibitors, they can serve as defoaming agents and emulsifiers, aid in setting of pectin gels, and have a strong effect on the taste of a food [41]. With a characteristically sour taste, organic acids have an important role in the flavor of fruits and their juices by balancing the sugar/acid ratio [42]. The inhibitory effect of organic acids depends on the undissociated form, as well as its ability to donate hydrogen ions in an aqueous system [43]. The degree of dissociation for a particular acid was related to its dissociation constant and the acidity of the product. Dissociation constants indicate the pH at which there is a 50/50 distribution of undissociated and dissociated forms. At lower pH, more undissociated acid was present [44]. In this form, the cell membrane was more permeable to the acid, allowing it to enter the cell. Upon entering the cytoplasm, the acid dissociates, thus lowering the internal pH of the cell and disrupting cellular functions [45]. In addition to affecting enzymes, excess protons in the cytoplasm upset the membrane potential necessary for energy production and transport across the cell membrane. Thus, organic acids can act on a cell by affecting both the external and internal pH. Malic acid (HOOC-CHOH-CH2-COOH), along with citric acid comprises the main organic acids in fruits [52]. In apples, malic acid was the predominant organic acid [53]. It was used for its flavoring and acidification properties in beverages, jams, jellies, and sherbets [54]. Malic acid has GRAS status. Unlike most other fruits, the main organic acid in grapes is tartaric acid (HOOCCHOH-CHOH-COOH) [55]. Tartaric acid is useful in supporting grape like flavors. As an antimicrobial agent, tartaric acid was believed to act only by lowering the pH of the product [56]. HYDROGEN PEROXIDE Hydrogen peroxide (H2O2) is an antiseptic (compared to a preservative) since it quickly acts to kill microorganisms and has no long-term or preserving effect [57]. This short-lived action was due to hydrogen peroxide’s rapid decomposition to oxygen and water upon contact with organic material. The antimicrobial action of hydrogen peroxide is not due to its oxidative properties as a molecule, but primarily in the production of other In both culture media and food system, the varying bacteriostatic and bactericidal effects of organic acids have been demonstrated. Chung and Goepfert [46] showed that various organic acids are bacteriostatic to Salmonella spp. at different pH levels. In our lab, apple cider and orange juice 61 Saranraj and Ramya, J Pharm Biol Sci 2016; 4(2): 58-73 powerful oxidants such as singlet oxygen, superoxide radicals and the hydroxyl radical [58]. These reactive oxygen species cause irreversible damage to a host of cell components such as enzymes, membrane constituents and DNA. In fact, aqueous solutions of H2O2 alone will not cause protein, lipid or nucleic acid modification without the presence of radical formation catalysts [59]. The H2O2 is naturally produced by enzymatic systems and is notably utilized by phagocytes in the destruction of bacteria within the phagolysozome [60]. and the vapor-phase [71]. As a water disinfectant, hydrogen peroxide had only a moderate immediate effect on Escherichia coli, but substantial immediate effect on Salmonella typhi [72]. Hydrogen peroxide has been used as an antimicrobial agent since the early 1800’s, and is well known for its use as a topical skin application in 3 % concentrations [73]. In foods, hydrogen peroxide was used as a disinfectant in milk as early as 1904 [74]. Hydrogen peroxide has GRAS status and was approved by the FDA for packaging and surface sterilization in the food industry. Hydroxyl radical (HO.) production likely plays the largest role in the toxicity of hydrogen peroxide [61]. When produced adjacent to DNA, hydroxyl radicals are unique in that they can “both add to DNA bases and abstract H-atoms from the DNA helix” [62]. Hydroxyl radicals may also damage cell membranes. In a study of model membrane systems, Juven and Pierson [63] found that the hydroxyl radicals (generated from hydrogen peroxide) increased lipid peroxidation as well as the ion permeability of model membrane systems, though via independent mechanisms. Furthermore, after 17 minutes of hydroxyl radical exposure, complete membrane breakdown was observed. Allowed uses of hydrogen peroxide as a direct additive to foods are limited. For antimicrobial purposes, H2O2 was allowed for treating milk used in cheese manufacturing, thermopile free starch production and the preparation of modified whey, at levels of 0.05, 0.15 and 0.4 % respectively. It was used as an oxidizing and reducing agent in wine, dried eggs, and corn syrup, and as a bleaching agent in tripe, beef feet, instant tea, colored cheese whey and certain emulsifiers. Residual peroxide must be removed by an appropriate means, typically by addition of catalase. Production of HO from H2O2 has been reported to occur in a number of ways. A commonly cited example is the Fenton reaction whereby a reducing agent such as the superoxide radical reduces Fe3+ to Fe2+, which then reacts with H2O2 to produce hydroxyl anions, hydroxyl radicals, and Fe3+ [64]. Accordingly, growing Staphylococcus aureus cells in broths of increasing iron concentrations was found to increase killing by H 2O2, whereas addition of HO. scavengers had a protective effect against such killing [65]. In a contrasting study, the ferryl radical, not the hydroxyl radical was indicated as the DNA damaging species in Escherichia coli [66]. The use of hydrogen peroxide to extend the shelf life of minimally processed fruits and vegetables was reviewed by Sapers and Simmons [75]. Applied as a vapor, 60 minutes of hydrogen peroxide exposure improved the shelf life of whole cantaloupe and drastically reduced the mold count on raisins. Similarly, in two varieties of grape, 10 minute applications of 40 ºC vapor phase H2O2 was found to significantly reduce Botrytis cinera spores and enhance shelf life without affecting grape color [76]. Vapor phase treatments of mushrooms showed excessive browning, but 30 second washes treatment with 5 % H2O2 and subsequent erythorbate dip (browning inhibitor) gave acceptable bacterial control without compromising color. On apple disks, 6 % hydrogen peroxide gave a greater reduction of Salmonella Chester than trisodium phosphate, calcium hypochlorite, or sodium hypochlorite [77]. While products such as zucchini and bell peppers show promise for use of H2O2 in controlling soft rot, others like strawberries and raspberries show great sensitivity to anthocyanin bleaching at bactericidal peroxide levels [78]. There is a substantiated correlation between temperature and the antimicrobial efficacy of hydrogen peroxide. Toledo et al. [79] found a notable increase in the sporicidal activity of H2O2 as the temperature increased above room temperature. In liquid whole egg, 1 % H2O2 was A host of research related to the activity of hydrogen peroxide on various bacteria, molds and yeast has been performed. Its activity appears greatest against anaerobic and Gram negative bacteria [67]. Lillard and Thomson [68] found that concentrations of 5,300 – 12,000 ppm in poultry chiller water reduced Escherichia coli populations 97 to > 99.9 %. In addition, the Enterobacteriaceae were found to be more sensitive than other organisms tested. Escherichia coli showed a Dvalue of 0.57 minutes when exposed to 3 % H 2O2, compared to 2.35 minutes for Staphylococcus aureus, 8.55 for Aspergillus niger and 18.3 for Candida parapsilosis [69]. The significant sporicidal activity of H2O2 on Bacillus subtilis spores was witnessed in both the liquid phase [70] 62 Saranraj and Ramya, J Pharm Biol Sci 2016; 4(2): 58-73 more effective (~1 log) at decreasing survival of Salmonella typhimurium in 24 hours in comparison to the same peroxide concentration [80]. Kuchma [81] noted a synergistic effect (killing of Escherichia coli and Pseudomonas aeruginosa) between microwave heating and low H2O2 concentrations, with maximum lethality at 50 °C and 0.08 % H2O2. Smith and Rollin [86] showed that the sorbic acid was an excellent fungistatic. It has also been placed on the list of food additives generally recognized as safe under conditions of intended use. Ingram et al. [87] noted that the DHA has a low dissociation constant, which makes it effective in low-acid or neutral media, but that it has a low activity against bacteria. They also stated that the U. S. Food and Drug Administration have evaluated the acute toxicity as approximately equal to that of carbolic acid. Nevertheless, the frequent appearance in the literature of DHA studies on spoilage organisms made it desirable to include it in their study. It was approved for bananas up to 10 ppm in the edible portion [88]. Though, little if any work related to H2O2 use in juice has been done, an important observation is that the efficacy of H2O2 appears to increase with decreasing pH. Hydrogen peroxide was found to be bacteriostatic towards Pseudomonas aeruginosa at pH 5.0, yet 1.5 m mol were required at pH 8.0. In addition, a 3 % solution of hydrogen peroxide was sporicidal against Bacillus subtilis in 3 hours at pH 5.0, but needed 6 hours to achieve the same effect at pH 6.5 and 8.0 [82]. Thus, hydrogen peroxide might be more effective in combination with acidulants such as organic acids. Bell et al. [89] found that 0.1 % sorbic acid inhibited lactic acid bacteria at pH 3.5, and yeasts at pH 4.5. They found that the toxicity was directly related to the concentration of undissociated acid and therefore a function of pH, just as with sodium benzoate. Robinson and Hills [90] reported that sodium sorbate and mild heat increased the storage life of apple cider, peach slices, and citrus fruit salads. Deinhard et al. [91] reported the optimum pH range for A. acidoterrestris growth of the organism in BAM was 2.5 to 5.8 over a temperature range of 35 to 55ºC with an optimum at 42 to 53 ºC, and McIntyre et al. [92] reported growth of A. acidoterrestris on PDA over a pH range of 3.0 to 5.3 at 30 to 55ºC. Previdi et al. [93] also stated that all A. acidoterrestris strains tested were able to grow on TA (pH 4.91), OSA (pH 5.09), and MEA (pH 4.0). CONTROL OF MICROBIAL SPOILAGE IN FRUIT JUICES Fruits contain high levels of sugars and other nutrients and they possess an ideal water activity for microbial growth. Their low pH makes them particularly susceptible to fungal spoilage because a big part of the bacterial competition was eliminated since most bacteria prefer near neutral pH. Some fungi are plant pathogens and can start the spoilage from the field while others, although they could contaminate the fruits in the field, actually proliferate and cause substantial spoilage only after harvest when the main plant defenses are reduced or eliminated. Walls and Chuyate [94] reported A. acidoterrestris growth in Orange Serum Broth at pH 2.5 to 5.0 over a temperature range of 20 to 55 ºC. According to Lewis [95], the Centre for Food Safety and Applied Nutrition found in its preliminary study that unpasteurized juices accounted for 76 % of juice contamination cases reported between 1993 and 1996. It is estimated that 16000 to 48000 illnesses per y can be attributed to juices [96]. Information compiled by Beuchat [97] provides an overview of food borne pathogens in different vegetable and fruit products. The frequency of microorganisms such as Salmonella, enterovirulent Escherichia coli, Listeria monocytogenes and Campylobacter are subject to wide variation from study to study. The prevalence of Campylobacter was mostly at levels < 3 %, whereas the prevalence of Salmonella is higher. In a majority of reports the frequency of Salmonella typhi was between 4 and 8 %. Escherichia coli and Listeria monocytogenes were in general found in a higher frequency compared to Salmonella. The presence of pathogenic Phillips and Mundt [83] showed that the lactic acid bacteria grew normally in pickle fermentations, while the scum yeasts were completely inhibited by 0.1 % sorbic acid. Their observations had been made without control of pH, which remained above 4.0 throughout their study. Wolf [84] reported that the dehydro acetic acid (DHA) or its sodium salt effectively inhibits undesirable microbial activity when added to a waxed food wrapper, or when used as a dip for dried fruits. He stated that it could be added to foods if shown to have no harmful effect on consumers. Von Schelhorn [85] review indicates that the effectiveness of preservatives has been frequently observed to vary with the species of organism. This study therefore designed to evaluate the above preservatives against pure cultures of organisms causing spoilage of citrus products under conditions simulating citrus salads exposed to a temperature favourable for microbial growth. 63 Saranraj and Ramya, J Pharm Biol Sci 2016; 4(2): 58-73 microorganisms on raw fruits and varies considerably. Often no pathogens are detected. In other surveys high percentages of samples contaminated with pathogens was observed. Surveys of the presence of parasites or viruses are fewer because the lack of detection methods that can be applied to fruits. Saccharomyces cerevisiae ascospores in fruit juices and a model juice buffer at pH 3.5 to 5.0. Approximately, 0.5 to 1.0 × 106 ascospores/mL were pressurized at 300 to 500 MPa in juice or buffer. D-values ranged from 8 sec to 10.8 min at 500 and 300 MPa, respectively. The range for zvalues was 115 to 121 MPa. No differences in D or z-values among buffers or juices at any pH were determined, indicating little influence of pH in this range and absence of protective or detrimental effects of juice constituents. Beuchat [98] provides an overview of food borne pathogens in different fruit products. The frequency of microorganisms such as Salmonella, Escherichia coli, Listeria monocytogenes, Campylobacter and Cyclospora are subject to wide variation from study to study. The prevalence of Campylobacter was mostly at levels of 3 %, whereas the prevalence of Salmonella was higher. In a majority of reports, the frequency of Salmonella was between 4 and 8 %. Escherichia coli and Listeria monocytogenes were in general found in a higher frequency compared to Salmonella. A conclusion of the report was that the presence of pathogenic microorganisms on raw fruits and vegetables varies considerably. Often no pathogens were detected. In other surveys high percentages of samples contaminated with pathogens was observed. Surveys of the presence of parasites or viruses are fewer because the lack of detection methods that can be applied to fruits. According to Eguchi [101], K medium and OSA are both suitable growth media for A. acidoterrestris. Five strains of A. acidoterrestris isolated from various juices and canned tomatoes were streaked onto OSA, Tomato Juice Agar Special (TJAS), PDA (each adjusted to pH 3.5, 4.0, 4.5 and 5.0), DTA (pH 7.4), and K medium (pH 3.7). All five isolates grew on OSA (pH 5.0) and K medium (pH 3.7) at 35 ºC. According to Pettipher [102], Alicyclobacillus failed to grow on Nutrient agar and Tryptone Soy agar at pH 7.3, but grew well on BAM medium, PDA and OSA. Of these media, it was determined that OSA allowed the highest recovery. Narta Mari et al. [103] isolated Mucor puriformis from orchard soils and from packing house dumptank waters. Pathogen propagates were not found in fruit sample washing. The population of the pathogen peopagules fluctuated in an annual cyclic pattern declining in warm months and increasing after harvest. The viability of sporangiospores was markedly affected by rain. There was a good correlation between the number of recovered propagules in the soil and the amount of rainfall. M. piriformis isolates caused decay on pear at 0 °C after 14 days. Wisse and Parrish [99] studied the occurrence of spore-forming thermo-acidophilic bacteria, including Alicyclobacillus and Sulfobacillus, in citrus fruit growing and processing environments. Isolates were obtained from seven of eighteen soil samples taken from citrus orchards, surfaces of unwashed fruit at eight of ten processing plants, on surfaces of six of nine washed fruits and in condensate water used to wash fruits in six of seven facilities examined. Finding these bacteria in condensate water generated in the processing of citrus juice concentrates was significant because it indicates that the microorganisms are likely to be present in the water used to wash fruits. MPN based population estimates of washed and unwashed fruits showed that approximately 46 spores/fruit of spore-forming, thermo-acidophilic rods (STAR) were detected. Isolation of STAR from fruit surfaces was expected due to cross contamination with soil or other contaminated fruits during fruit growing and fruit harvesting/handling procedures. However, researchers were surprised that STAR was found on washed fruit from six plants. Although, this may be due to the fact that there were substantial numbers of STAR spores in condensate water used for fruit washing. Mickee et al. [104] analyzed red rasp berry fruit spreads sweetened with sugar or raspberry, red grape and apple juice concentrates for chemical, physical and sensory properties at 1.12 and 24 weeks. All pH values were between 3.0 and 3.5 while all aw were above 0.81 samples were dark red but become duller over time. Mold was detected in all samples at 24 weeks. Acceptable but inversion processing was not recommended for fruit spread preparation. John Moore et al. [105] isolated a Gram negative Bacillus from a batch of fruit flavored bottled water, which had spoiled as a result of bacterial overgrowth (>106 CFU/ml). The spoilage organism was extremely difficult to identify phenotypically and was poorly identified as Pasturella sp. employing the identification scheme, which gave Zook et al. [100] determined high pressure inactivation kinetics (D and z values) of 64 Saranraj and Ramya, J Pharm Biol Sci 2016; 4(2): 58-73 the profile 5040000 base pairs. Molecular identification through PCR amplification of a partial region of the 16S rRNA gene followed by direct automated sequencing of the PCR amplicon allowed identification of the organism. spoiled within 1 week. However, the addition of 2000 ppm vanillin resulted in suppression of the growth of spoilage microbes. This level of vanillin did not affect survival of acid-adapted Escherichia coli. 1000 ppm vanillin was also effective in controlling growth, but lower concentrations only briefly delayed the onset of microbial spoilage. Nisin was ineffective in preventing spoilage, and in a test of yogurt containing fresh peaches, nisin hastened growth of spoilage microbes. Onimawo et al. [106] conducted the physicochemical and nutrient evaluations of African bush mango seeds and pulp. The seeds contained 3.36 %, 7.70 %, 65.46 %, 2.26 %, 10.23 % and 10.7 % of moisture, crude protein, crude fat and mineral ash. The physicochemical analysis of pulp showed that it contained 0.112 cm3 titrable acidity, 0.21 %. Water soluble ash, 459.7 mg/100 ml reducing sugars, 49.1 % non reducing sugar, 10.0 % total solids, 1.2 × 103 lvsm-2 viscosity and 1.012 specific gravity. Ascorbic acid and calcium contents were 66.7 mg/100 ml and 262.3 mg/100 ml, respectively. The pulp was slightly acidic (pH 5.8) which indicates that it may not be easily spoiled by microorganisms. Adisa [110] investigated the production of amylolytic, cellulolytic and pectinolytic enzymes by Aspergillus flavus and A. fumigatus. The two fungi were cultured on wheat offal and liquid crystalline carboxy methyl cellulose media. A. flavus produced amylases on basal and starch containing media while A. fumigatus could only produce amylases on starch medium. The cellulolytic activities of filtrates from culture or infected fruits showed that A. flavus produced lesser quantities of cellulolytic enzymes than A. fumigatus. At 25 °C and at a pH range of 6 – 8, A. flavus best produces amylases and cellulases, while Aspergillus fumigatus showed highest activities of the two enzymes at 35 - 40 °C and at pH 7.0. Two pectinolytic enzymes polymethylgalacturonase and pectinmethyltrans - eliminase were identified in vivo with the two molds. An endo polygalacturonase in addition to these two pectinolytic enzymes was well associated with A. fumigatus. Dilnisi et al. [107] screened Lasiodiplodia theobtomae, Thielaviopsis paradoxa, Colletotrichum musae, Colletotrichum gloeosporioides, Fusarium verticillioides and Fusarium oxysporum for sensitivity to Na2CO3, NaHCO3, CaCl2 and NaCl2. The spore germination of all pathogens was completely inhibited by Na2CO3 4 g/L, NaCl 5 g/L and NaHCO3, CaCl2, and NaCl2 6 g/L each. Dipping the incidence of crown rot 17 days after harvest in fruits treated with NaCl2 by 67 % with NaHCO3 by 62 %, with NaCl by 38 % and with CaCl2 by 33 % Na2CO3 treated fruits had the same incidence of crown rot as untreated fruits. Akpan and Kovo [111] examined the production and preservation of Passion Fruit Juice to reduce the spoilage and to increase the shelf life of the juice. The preservation of the juice was carried out using sugar, benzoic acid, citric and a combination of citric and benzoic acid under room temperature. The result revealed that the juice maintained its colour, aroma and tastes for at least one month when 30 % benzoic acid was used as preservative. The juice under other preservation like 4 % sugar went bad after three days, while that of 4 % citric acid maintained its qualities for one week and some days, but thereafter the aroma started to fade. The combination of 3 % benzoic acid and 4 % citric acid maintained the qualities of the juice fairly between two to three weeks. The preservation used also altered the pH so that it was impossible for pathogens to exist at such a low pH environment. Sulali Anthony et al. [108] collected the crown out pathogen isolated from banana samples from 12 locations and the collected pathogens were Lasiodiplodia theobromae, Fusarium, Proliferatum and Colleotrichum musae. Fungal pathogens isolated were able to cause crown rot disease alone as in combination. Disease severity was highest when combination of virulent pathogens were used Cymbopogon nardus and Ocimum basilicum oils displayed fungicidal activity against C. musae and F. proliferatum between 0.2 - 0.6 % (v/v) in a poisoned food bioassay. Victoria Penney et al. [109] proposed that fruit yogurt made with minimally processed ‘fresh’ fruit has the potential to increase consumption rates of yogurt. The efficacy of vanillin, nisin and fresh cranberries to control microbial spoilage of a fresh fruit yogurt containing wild blueberries was tested. After introducing wild blueberries, yogurt contained a large community of yeast and bacterial cells. Yogurt with only wild blueberries was visibly Vasantha Rupasinghe et al. [112] tested the antimicrobial effect of vanillin against four pathogenic or indicator organisms: Escherichia coli, Pseudomonas aeruginosa, Enterobacter aerogenes and Salmonella enterica subsp. enterica serovar Newport and four spoilage organisms; Candida albicans, Lactobacillus casei, Penicillium 65 Saranraj and Ramya, J Pharm Biol Sci 2016; 4(2): 58-73 expansum and Saccharomyces cerevisiae that could be associated with contaminated fresh - cut produce was examined. The minimal inhibitory concentration (MIC) of vanillin was dependent upon the microorganism and this ranged between 6 and 18 mM. When incorporated with a commercial anti-browning dipping solution calcium ascorbate, Nature Seal, 12 mM vanillin inhibited the total aerobic microbial growth by 37 % and 66 % in fresh-cut ‘Empire’ and ‘Crispin’ apples, respectively, during storage at 4 °C for 19 days. Vanillin (12 mM) did not influence the control of enzymatic browning and softening by Nature Seal. These results provide a new insight for vanillin as a potential antimicrobial agent for refrigerated freshcut fruits. propolis showed greater antifungal activity than sodium benzoate. Izuagie and Izuagie [115] determined the ascorbic acid content of the juices of four different citrus fruits – orange, tangerine, grapefruit and lime in order to know which fruit would best supply the ascorbic acid need for the body. The results of their research showed that the orange had the highest value of ascorbic acid, 600 μg/ml followed by grape, 446 μg/ml and then tangerine, 415 μg/ml. Lime had the least value, 306 μg/ml. It follows that orange would supply more ascorbic acid per millilitre for body need compare to the other three fruits. In fact, the value of ascorbic acid in orange was about twice that of lime. Magashi Abdulkadir and Bukar Aminu [116] determined the antibacterial and antifungal effects of high pH (9, 10) and paraffin wax. Determination of antibacterial and antifungal activity of the combined treatments was achieved by aerobic mesophilic count of bacteria and fungi on the surface of the tomatoes, peppers and oranges using serial dilution and pour plate techniques and compared prior to and after 4 days of treatment with buffer (pH 9, 10) and wax for 3 min using dipping method. Reduction in bacterial and fungal count indicates antifungal and antibacterial activity. A bacterial count reduction of 84.3 (control), 63.4 (pH 9) and 78.2 % (pH 10) and fungal count reduction of 53.6 (control), 43.4 (pH 9) and 73.5 (pH 10) were achieved after 4 days of treatment respectively. Their study showed that the control (unwaxed) had similar antibacterial and antifungal effect as waxed fruits at pH 9 and 10, except for pH 10 that had higher reduction of fungal counts than the control, showing prospect of higher activity with wax at higher pH than 10 [117]. Wissanee Supraditareporn and Renu Pinthong [113] conducted experiments to study the physical, chemical and microbiological properties of fresh orange juices immediately after harvest and different storage periods and storage temperatures. Some of the parameters could be used as indicator of quality loss of the juices such as colour and, total soluble solid, titratable acidity, ascorbic acid and total plate counts varied with storage time and temperature. The shelf life of orange juices had only 1 day shelf life at 25 ºC, 6 days at 4 ºC and more than 21 days at -18 ºC. The orange juice at 18 ºC still has a good quality throughout the storage time; however, ascorbic acid contents were reduced. Ayse Nedret Koc et al. [114] examined the antifungal effect of ethanol extract of Turkish propolis (EETP) treatments in four non-pasteurized fruit juices including apple, orange, white grape and mandarin against 6 different yeasts isolated from the corresponding spoiled juices. These isolated yeasts include: Candida famata, C. glabrata, C. kefyr, C. pelliculosa, C. Parapsilosis and Pichia ohmeri. Minimum Inhibitory Concentration (MIC) ranges were determined responding to the National Committee for Clinical Laboratory Standards (NCCLS) M27-A that were slightly modified with broth microdilution method. In their study, the presence of propolis in apple (pH = 3.9), orange (pH = 3.7), white grape (pH = 3.8) and mandarin (pH = 3.4) juices ranging from 0.01 to 0.375 mg/ml inhibited the growth of all spoilage yeasts at 25 °C. The MIC ranges of propolis were 0.02 – 0.375, 0.04 – 0.375, 0.01 – 0.185, 0.02 – 0.185 and 0.04 – 0.375 mg/mL in mandarin, apple, orange, white grape juices and RPMI medium. MIC ranges of sodium benzoate which was used as positive control, were 80 – 320, 80 – 320, 40 – 640, 40 – 80 and 320 – 1280 mg/ml in mandarin, apple, orange, white grape and RPMI medium as blank control, respectively. In terms of MIC ranges, Rosalia Trias et al. [118] evaluated the efficacy of lactic acid bacteria (LAB) isolated from fresh fruits as biocontrol agents against the phytopathogenic and spoilage bacteria and fungi, Xanthomonas campestris, Erwinia carotovora, Penicillium expansum, Monilinia laxa and Botrytis cinerea. The antagonistic activity of 496 LAB strains was tested in vitro and all tested microorganisms except Penicillium expansum were inhibited by at least one isolate. The 496 isolates were also analyzed for the inhibition of Penicillium expansum infection in wounds of Golden Delicious apples. Four strains reduced the fungal rot diameter of the apples by 20 %; only Weissella cibaria strain TM128 decreased infection levels by 50 %. Ermi Sukasih and Setyadjit [119] determined the heat resistance and heat adequacy value of pure citrus juices. The method used was heating the tubes containing pure citrus juices with 66 Saranraj and Ramya, J Pharm Biol Sci 2016; 4(2): 58-73 combination of time and temperature of pasteurization at 55 ºC, 60 ºC, 65 ºC, 70 ºC, 75 ºC and 80 ºC during 5, 10, 15 and 20 minutes. Their results showed that bacterium population with z value equal to 30 ºC had higher heat resistance value than yeast/mold population with z value equal to 17.24 ºC. P value for 3D pasteurization of pure citrus juices was 11.26 minutes for acid foods, which meant that it will achieve heat adequacy treatment if it was pasteurized at time and temperature having P value equal to 11.26 minutes. Perni et al. [120] described the inactivation by cold atmospheric plasmas of one pathogenic and three spoilage organisms on the pericarps of mangoes and melons. The operating voltage necessary for efficient microbial decontamination of fruit pericarps was first established using Escherichia coli at a concentration of 107 CFU/cm2 on the surface of mango. It was found that, when the plasma was sustained slightly above its breakdown voltage of 12 kV, no inactivation was detected when cells were plated onto Tryptone soya extract agar (TSA). However, when plated onto Eosin methylene blue agar, sublethal injury corresponding to approximately 1 log reduction was achieved, whereas on TSA supplemented with 4 % NaCl a greater reduction of 1.5 log was revealed. When the voltage was increased by 33 % to 16 kV, a reduction in cell counts of 3 log was achieved on all three plating media. Further investigations at these new operating conditions were conducted using a range of spoilage microorganisms all at a surface concentration of 106 CFU/cm2 on the pericarps of mango and melon. Pantoea agglomerans and Gluconacetobacter liquefaciens were reduced below the detection limit after only 2.5 s on both fruits, whereas Escherichia coli required 5 s to reach the same level of inactivation. Saccharomyces cerevisiae was the most resistant organism studied and was reduced in numbers below the detection limit after 10 s on mango and 30 s on melon. The optical emission spectra generated by the cold atmospheric plasma at both high and low operating voltages were compared in order to identify putative lethal species. ambient temperature were also determined. After 10 days of storage, the total viable counts increased from 0.6 × 103 cfu/g to 5.3 × 103 cfu/g and to 5.5 × 103 cfu/g in the HDP- and LDP-packaged watermelon samples, respectively. The total fungal counts increased from 0.5 × 103 cfu/g to 6.7 × 103 cfu/g and to 7.2 × 103 cfu/g in the HDP- and LDPpackaged watermelon samples. Reddy et al. [122] estimated the losses caused by post-harvest fungal diseases in sweet orange and acid lime at field, wholesale, retail and consumer levels. The extent of loss due to the post-harvest fungal spoilage was varied at different stages of marketing. The post-harvest fungal spoilage was mostly due to green mold (Penicillium digitatum), black mold (Aspergillus niger) and sour rot (Geotrichum candidum) while the other diseases were only to limited extent. Generally, the fungal spoilage was more in sweet orange compared to acid lime. The extent of damage was high at retail level which was 43.8 % in sweet orange and 36.8 % in acid lime respectively. Tamaliza et al. [123] evaluated Bacillus licheniformis for the control of gray mold of apple caused by Botrytis mali. Dual culture cell free metabolite and volatile tests showed that Bacillus licheniformis inhibited growth of the pathogen. Bacillus lichniformis appeared to be a good antagonist of gray mold on apple 20 °C and 4 °C. It reduced Bacillus lesion diameter to 9 - 11 mm compared with to 32 - 41 mm in the control at 4 °C. At 20 °C, the lesion diameter was reduced to 3.5 8.4 mm for the antagonistic treatment and to 24.8 38.2 mm for the control treatment after 14 days. Juan Calvo et al. [124] assessed the antagonistic activity of the mixtures Rahnella aquatitis, Rhodotorula glutinis and R. aquatitis, Cryptococcus laurentii against Penicillium expansum (cause of blue rot) and Botrytis cinerea (cause of grey rot) on apple fruit at 4 °C and 9.5 % relative humidity (RH). Under these cold storage conditions, the mixture R. aquatitis - R. glutinis inhibited the development of B. cinerea and Penicillium expansum in apples stored for 40 days and reduced the incidence of disease produced by these moulds to nearly zero. Nwachukwu et al. [121] collected freshly sliced watermelon from different street vendors to determine their microbiological quality. Eight different microbial isolates were obtained from the sliced watermelon samples, namely Escherichia coli, Klebsiella aerogenes, Proteus mirabilis, Staphylococcus aureus, Lactobacillus spp., Saccharomyces cerevisiae, Rhizopus stolonifer and Mucor spp. The effects of high density polyethylene (HDP) and low density polyethylene (LDP) packaging bags on the microbiological quality of freshly sliced watermelon, stored at Behnas Solaimani et al. [125] investigated the antifungal effects of the herbal essential oil of Shiraz thyme against the producing agent of Penicillium digitatum and Penicillium italicum on the Washington Navel Orange fruit. In their study, treatments were three level of Shiraz thyme essential oil (0 µl, 200 µl and 400 µl) in the forms of spray and dipping for 10 and 20 min in lab (in vivo) condition. This investigation was arranged by 67 Saranraj and Ramya, J Pharm Biol Sci 2016; 4(2): 58-73 the Completely Randomized Design (CRD) with three replications that each containing four fruit and the contamination of fruits was recorded for 4 week. The chemical composition of essential oils isolated by hydrodistillation from the aerial parts of Shiraz thyme was analyzed by GC and GC–MS. Carvacrol (63.17 %), thymol (15.1 %), p-cymene (7.87 %), linalool (3.88 %), á-pinene (3.19 %) and Carvacrol methyl ether (1.92 %) were found to be the main constituents in Zataria multiflora essential oil. The results indicated that the essence of Shiraz thyme was not effective on the green fungus and the highest preventing effect of the essence was in the joint from related to the mixture of the three essences treatment. paper and incubated at 25 °C to allow the growth of fungi for a period of 1 week. Fungal species developed on seeds and fruit pieces were isolated on Potato dextrose agar for identification. Twenty species from 14 genera of fungi have been isolated from 13 different varieties of date-palm as seedborne fungi while 39 species of 16 genera of fungi were isolated as fruit spoilage fungi. Alternaria alternata, Aspergillus flavus, Aspergillus niger, Fusarium oxysporum and Fusarium solani were the predominant species in both seed-borne and fruit spoilage fungi. Galgozy et al. [129] evaluated the antibacterial effect of fruit juices and pomace extracts from 13 wild and cultivated fruits (Prunus avium, P. cerasus, P. armeniaca, Crataegus monogyna, Morus alba, M. nigra, Ribes nigrum, R. rubrum, R. uvacrispa, R. nidigrolaria, Rubus idaeus and R. fruticosus) against two foodborne enteric pathogens (Salmonella ser. Typhimurium and Campylobacter jejuni) by Broth micro dilution assays. Juices and extracts of sour cherry, apricot, raspberry, blackcurrant, redcurrant, gooseberry and jostaberry efficiently inhibited the growth of both bacteria (growth ≤ 25 %). Juices and extracts from cherry (red and yellow cultivars), hawthorn, blackberry and pomace extracts from black and white mulberry had a similar strong inhibitory effect on the growth of C. jejuni, but had weak or no effect on Salmonella typhimurium. Sour cherry, josta berry and raspberry pomace extracts revealed a substantial antibacterial effect at both acidic and neutral pH. Zamani et al. [126] used the antagonistic bacterium, Pantoea agglomerans for controlling citrus green mould caused by Penicillium digitatum at 20 °C and 4 °C. This isolate was also assessed in combination with dipping in 3 % sodium bicarbonate solution at 24 °C and 45 °C on artificially inoculated Thomson navel oranges. Application of the antagonist alone reduced green mould by more than 75 % at both temperatures, but was not as effective as Imazalil. The antagonistic bacterium was completely tolerant to sodium bicarbonate upto a concentration of 3 %. In addition, its efficacy for controlling green mould was improved at least by 5 % and 11 % when combined with 3 % sodium bicarbonate at 24 °C and 45 °C. Abhinaba Gosh [127] found out the organisms which make tomato more susceptible to spoilage. Out of the 30 Rose Bengal agar plates which were inoculated and incubated vigorous growth of fungi was observed in 26 plates with moderate growth on other 4 plates. Also 30 other plates of Nutrient agar were inoculated with the sample and very scanty growth of bacterial colonies was observed in 3 - 4 plates and mostly occupied by fungal colonies. Thus, it was found that fungi were the source of spoilage in most of the samples rather than bacteria. Further morphological studies were done to know the fungal member responsible for the spoilage. Among the fungi, it was found that Aspergillus niger and Fusarium were found in most of the spoiled samples with a few samples containing Penicillium too with Aspergillus niger dominating all the plates. Akpan and Kovo [130] examined the production and preservation of Passion Fruit Juice to reduce the spoilage and to increase the shelf life of the juice using chemical preservatives. The preservation of the juice was carried out using sugar, benzoic acid, citric and a combination of citric and benzoic acid under room temperature. The result revealed that the juice maintained its color, aroma and tastes for at least one month when 30 % benzoic acid was used as preservative. This happens to be the best among all. The juice under other preservation like 4 % sugar went bad after three days, while that of 4 % citric acid maintained its qualities for one week and some days, but thereafter the aroma started to fade. The combination of 3 % benzoic acid and 4 % citric acid maintained the qualities of the juice fairly between two to three weeks. Hashiem Al Sheik [128] collected the seeds and fruits of different date palm varieties from local market, where further experiments for isolation of fruit spoilage and seed-borne fungi were conducted by using common technique of wet blotter method. A total number of 100 seeds and 100 cubes obtained from the fruits were put on wet filter Gobbi et al. [131] described the application of an electronic nose equipped with a Metal Oxide Semiconductor sensor array for the detection of Alicyclobacillus acidoterrestris and A. acidocaldarius artificially inoculated in peach, 68 Saranraj and Ramya, J Pharm Biol Sci 2016; 4(2): 58-73 orange and apple fruit juices. Overall the system was able to detect the presence of Alicyclobacillus spp. in all the tested fruit juices at 24 hrs from inoculation. The electronic nose could detect bacterial concentration as low as <102 colony forming unit/ml and it was also able to classify bacterial contamination independently of the Alicyclobacillus species. The Gas Chromatography – Mass Spectrometry (GC-MS) characterization of the volatile profile of orange juices confirmed the existence of quantitatively different patterns between contaminated and uncontaminated samples. Isabel Alegre et al. [134] proposed that Escherichia coli, Salmonella and Listeria innocua increased by more than 2 log10 units over a 24 hrs period on fresh cut Golden Delicious apple pings stored at 25 °C and 20 °C. Listeria innoua reached the same final population level at 10 °C meanwhile Escherichia coli and Salmonella only increased 1.3 log10 units after 6 days. Only Listeria innoua was able to grow at 5 °C. No significant differences were observed between the growths of food born pathogen on fresh-cut Golden Delicious. Granny Smith and Shampion apples stored at 25 °C and 5 °C. These results highlight the importance of avoiding contamination of fresh cut fruit with food borne pathogens and the maintenance of the cold chain during storage until consumption. Ethiraj and Suresh [132] studied the nature and distribution of microorganisms associated during processing of mango. Bacteria outnumbered yeasts in both unwashed and washed fruits. Washing the fruits in running water reduced the surface flora considerably. Because of low pH and high sugar content, mango products are highly susceptible to spoilage by yeasts. Therefore, the yeast flora isolated during different stages of processing was identified. Species of Kloeckera and Hyphopichia in unwashed fruit and Kloeckera and Pichia in washed fruits were the predominant yeasts. However, flesh from both unwashed and washed fruits contained species of Kloeckera, Hyphopichia and Candida as the major yeasts. Species of Candida, Kloeckera and Kluyveromyces were the predominant yeasts in the unheated raw mango pulp whereas heated pulp did not show the presence of any yeast. Effect of sodium benzoate, potassium sorbate and potassium metabisulphite on growth of some predominant yeast was studied. It was found that the sodium benzoate at 500 ppm level inhibited all the yeasts except Saccharomyces ludwigii, while potassium sorbate and potassium metabisulphite at the same concentration inhibited all the yeasts. Jageethadevi et al. [135] investigated the inhibitory effect of chemical preservatives and organic acids on the growth of bacterial pathogens. Decrease in the growth of all the four bacteria were observed with increase in the concentration of acetic acid and citric acids. The growth of all the bacterial culture were effectively inhibited at 1000 µg ml-1 and lower inhibition zone was found at 200 µg ml-1. The inhibitory effect on the bacterial culture was more in acetic acid compared to citric acids. The effect of preservatives (potassium sorbate and calcium propionate) on the inhibition of growth of bacteria was studied and for all the cultures, the inhibition zone area increased with increase in the concentration of the preservatives. Vibrio parahaemolyticus, Shigella sonnei, Staphylococcus aureus and Salmonella typhimurium were effectively inhibited at 1400 µg ml-1. The inhibitory effect for all the bacteria was more in potassium sorbate compared to calcium propionate. CONCLUSION The present review concludes that the organic acids and hydrogen peroxide are of predominant efficacy in preservation of fresh fruit juices from the bacterial, fungal and other microbial isolates. 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