Determination of Traditional and Biologically Viable Methods for Food Preservation: A Review

Introduction

Foods are a substance that are consumed for nutritional and health purposes. It has been a plant and animal source, which contains proximate composition, minerals, and other organic substances. It is a susceptible to different form of degraded by oxygen available in the atmosphere, microbial factor, enzymatic reaction and the oth¬ers, being especial to investigate new systems of preserving food. It is also undergone spoilage due to microbiological factor, chemi¬cal and physical action [1]. However, the foods are requirements to preserve to keep their quality for a longer time. The basic problem of getting food has always been followed by the problem of a sat¬isfactory method for preserving it for later consumption. The basic traditional methods of food preservation-drying, curing, pickling, uses of sugar/salt, and different combinations have a lack of appli¬cation. The modern methods of food preservations are freezing, freeze-drying, and irradiating, have been however make possible the preservation of nearly all foods. The basics and advancements of various trivial and modern food preservation method, that are attributed to impede food spoilage and to yield longer shelf life, are discussed with their mechanisms, application manner, merit, and demerits. In general, the preservation processes consist of a combination of mild heat stress and low concentration of chem¬ical preservatives to control food spoilage and the outgrowth of pathogenic spore-forming bacteria, as well as retard the oxidation of fat that causes rancidity [2]. The bio preservatives are the most option derived from natural sources to preserve and increases the protecting safety of food and good suitable for food application with increasing demand of consumers for chemical free food prod¬ucts. To enlarge the shelf life of food products by uses of natural controlled microorganism and antimicrobial compounds gotten from microbes is called to as bio-preservation. The food preser¬vation controls are, the food by reducing the pH value, changing water activity and settling the redox potential of the product [3]. The major selected microorganism for bio-preservation are lactic acid bacteria and their metabolites. The functional food products along with natural raw materials promoting health instead of syn¬thetic additives have been strongly launched by the food product industry [4]. During the last decade, the food industries are looking for new natural bio-preservation, which could be promoted human health besides acting as food preservatives [5]. Thus, the overview and core objective of this review is to provide insights in to the researchers, technologists, and industry managements a compre¬hensive understanding, which could be highly useful to develop effective and integrated food preservative methods and to ensure food safety.

Traditional Food Preservation Methods

Drying

Drying is the oldest means of hampering the decomposition of food products [6]. The aim of drying is to getting a solid product with low water content [7]. Many microorganisms could grow at water activity above 0.95. According to stated, most of the mi¬croorganisms could not grow at water activity below 0.88. Most of drying has advantages, which, reduces weight, and volume of foods, facilitates foods storage, packaging, and transportation, and also provides different favors and smells. Nevertheless, these methods also have limitations. After during some important organ-oleptic are lost. During drying, some functional compound compo-nents such as vitamin C, Protein, fat and thiamine are lost [8-10].

Freezing

Freezing is the slow down temperature and inhibits the growth de-teriorative, chemical reaction, cellular metabolic response in hin-dered and pathogenic microbial in food product [11]. Not like oth¬er methods, freezing preserves food's taste, texture, and nutritional content. The heat transfer during freezing of a food item involves a complex situation of simultaneous phase transition and alteration of thermal properties [12]. The ice crystals formed by quick freez¬ing are much smaller and cases little damage to cell structure of food. Shorter freezing period protects the diffusion of sugar and prevents decomposition of foods during freezing [13].

Sugaring

Sugaring is used in many food products to prevent the growth of unwanted microorganisms. It has inhibition, which attributed to reducing the water activities as sugar draws moisture from tissues. The sugar formed and provides a medium for the growth of lactic acid bacteria that are responsible for the fermentation process. The plasmolysis of cells may available, because of the higher, osmotic pressure caused by sugars [14].

Pickling

Pickling is also the oldest method of preserving food in an edible anti-microbial. The chemical process of pickling methods is put the food product in an edible liquid, which prevent bacteria and other microorganisms. Kindly the pickling agents like the salt, cit-ric acid, vinegar, alcohol, and vegetable oil, particular olive oil, but also many other oils. According to the the microorganism safety of fruits and vegetables, preservative method including major preser-vative factors used in pickling technology [15]. The fruits and veg-etables could be contaminated with pathogenic microorganisms from various sources. In the pickling food products, acid, salt, and heating are main factors, which contribute to food preservation, and these factors are applied in combination. Therefore, found the combination effects of main factors is important to the correct ap¬plication of preservation factors, which can be, increases the mi¬croorganism safety and total quality of pickled food products.

Canning

The canning process involves placing food, sealing it in sterile cans, and heating the containers to inhibiting any remaining bacte-ria as a form of sterilization. Canning as a processing and preserva-tion method offers a unique advantage of preservation food of the sensory attributes of the fermented product, with the added elon¬gation of the shelf life [16]. Canning is a type of food preservation that was established with a combination of processes, such as heat¬ing, and cooling. Canning prevents the growth of microorganisms and inhibits the activity of enzymes. First, the raw materials must be properly treated because some foods, particularly fish, contain dangerous microorganisms such as Clostridium botulinum, which can be death.

Smoking

Smoking is one of the old methods of food preservation which to provide better sensory acceptability to the foods to deactivate enzymes and to deliver an antimicrobial effect. Smoked food prod¬ucts are mainly stored on chilled conditions, but they have a prob¬lem product when compared to dried and frozen food product. The shelf life of food items perishable by exposing them to smoked of the burning plant materials such as wood. The smoked is a number of pyrolysis food into the product, contain the phenols, syringol, guaiacol, these volatile phenolic compound’s help in dying and preservation of the food [17].

Curing

The biggest form of curing was removing. Always salt to add to speed up this process. In the part of world, it was a main to option raw salts from different origin (rock salt, sea salt, etc.). The mod¬ern instance of salts, which are used as preservatives like sodium chloride, sodium nitrate, and sodium nitrite. Even at high concen¬trations, sodium chloride (that is present in many food products) is capable of neutralizing the antimicrobial character of natural compounds [18, 19].

Fermentation

Fermentation is a method uses microorganism which to preserve food. It is a conversion food processing of carbohydrate to alcohol and carbon dioxide which using yeast, bacteria, and combination under anaerobic conditions [20]. Microorganism such as bacteria, yeasts, molds are the main groups of microbial that is involved in the fermentation of a wide range of food items, like dairy products, cereal- based foods, and meat products [21]. The fermentation in-creases the nutritional value, healthfulness, and highly digestibility of foods. These is the healthy optional to much toxic chemical pre¬servatives [22]. Some microorganisms preserve microbial patho¬gens in an environment toxic for themselves and other microor¬ganisms by producing acid. Starter microorganisms, salt, hops, controlled temperatures, controlled levels of oxygen and other methods are used to create the specific controlled conditions that will help the desirable organisms that produce food fit for human consumption. Equally, the resistance of some microorganisms to most commonly used preservatives has created problems for the food industry. In particular, modern consumer trends and food leg¬islation have left the successful attainment of this objective to be more of a challenge. Firstly, consumers demand high quality, pre¬servative-free, safe but minimally processed foods with extended shelf life. Secondly, legislation has restricted the use as well as the permitted levels of some of the currently approved preservatives in different foods. These consumer and legislative needs call for innovative approaches to preserve foods. Much research has been carried out on the antimicrobial effect of heat in combination with modified environmental factors such as low water activity, pH and ultra-high pressure, but very little has been reported on the combi¬nation of physical treatments with natural antimicrobials [23-26].

Bio-Preservation

The better alternative food preservation method, especially atten¬tion has been paid to bio preservation techniques that extended the shelf life and increases the hygienic quality, thereby minimiz¬ing the negative effect on the nutritional and sensory attribute. Bio preservation exploits the antimicrobial activities of some microor¬ganisms to inhibit the growth of spoilage and pathogenic microbes in foods. This biological approach seeks to minimize the addition of chemical additives to foods, such as nitrite, sodium chloride, and organic acids. Lactic acid bacteria (LAB) have been exploited for a decade production of fermented foods because of their ca¬pable to production good alter in the sensory attribute as well as prevent pathogenic microorganisms. Since they are distributed in many fermented foods product, it is supposed which most delegate actives of this group do not give rise to any health risk to man, and are appoint as generally recognized as safe organisms. The LAB, totally examine as food quality organisms, has a better promise as safety cultures. There are many prospective uses of safety cultures in different food systems. A number of various factors have been associating to give to the antimicrobial activity of LAB. These bacteria generate various antimicrobials, like lactic acid, acetic acid, hydrogen peroxide, carbon dioxide and bacteriocins, that can prevent pathogenic microorganisms, lengthen the shelf life and in¬creasing the protective of food products [27-31].

Lactic Acid Bacteria as Bio preservative

Lactic Acid Bacteria (LAB) is a kind of Gram-positive bacteria connected to an associate of structural, metabolic and physiolog- ical characteristics. They are included in the group of non-spores forming, non-respiring cocci or rods, catalase-negative, devoid of cytochromes; non- aerobic but aero-tolerant, fastidious, acid tol¬erant and exactly fermentative with lactic acid as the significant end product during the fermentation of carbohydrates. They have been unique from grains, green plants, dairy and meat products, fermenting vegetables and mucosal surface of animals Lindgren and [32]. The enhancing demand for high quality protects, pro¬cessed foods has created for natural food preservatives. The main food protective duty promised a number of criteria like acceptable low toxicity, stability to processing and storage, efficacy at less concentration, no deleterious effect on the food and economic vi¬ability.

Bacteriocins

Bacteriocins are secondary antimicrobial proteinaceous com¬pounds that are kills to sensitive strains and are produced by both Gram-positive and Gram-negative bacteria. Bacteriocin biological action appear through the certain receptors cited on the small mi¬crobial cell surface. Bacteriocins are dangerous toxins, frequently specific and always produced during the exposition of some bacte¬ria lineages to harmful conditions. When released in environment cause quick elimination of non-immune or non-resistant neighbor¬ing microbial cells to their action. Antibiosis occurred when two or more microorganism occur in an environment can be interfere on the growth and survival of other ones [33-36]. Bacteriocins are powerful toxins, offen specific and usually produced during the exposition of some bacteria lineages to stressful conditions. Bac¬teriocins are regular effective against Gram-positive bacteria situ¬ation to various genera and closely related species.

                                             Table 1. Classification and characteristics of bacteriocins

Class-IV (Circular peptides)

-Enterocin AS-48

Enterocin AS-48

Compatible with several chemical compounds like EDTA, lactic acid, per acetic acid, phosphoric acid, sodium hypochlorite, hyrdro-cinnamic acid

Bacillus spp., Geobacillus stearothermophilus, S. au­reus, L. monocytogenes, Brocothrix thermosphac-ta.

(Cobo Molinos A et al., 2008)

Application of Bio preservation

An importance of Bacteriocins for biological protection of food products; in totally, biological preservation approaches like attrac-tive as a preservative parameter in foods with decreased contents of ingredients like salt, sugar, fat and acid that always provide as factors potentially inhibitory to microbial growth. It is expected that biological preservation technique might be enjoy desirable consumer acceptance than their preservation counterparts that use traditional chemical preservatives. Many possible methods for the application of bacteriocins in the preservation of foods may be considered.

The kinds of product and the intrinsic as well as extrinsic parame¬ters existing during processing, storage and distribution will deter¬mine the especially approach of biological preservation required. In non-fermented refrigerated products, minimally processed meats, prepackaged vegetable salads, only those strains producing sufficient and potent amounts of bacteriocin but no other metabol¬ic compounds, at levels detrimental to the sensory quality of the product, can be applied. Currently, the methods of processing and preservation of foods can be produced having an effect less than lethal injury, and in the presence of bacteriocin, the injured cells can be death [37]. The process of antibacterial organization of the two bacteriocins from LAB, has been expressed that they were much antibacterial in union than when they were used alone [38]. This examination has led to put forward the assumption of these higher antimicrobial bands of colour and can be used benefit to design efficient natural food bio preservative (s).

Factors That Inhibiting Bacitracin Producing

Insufficient physical situation and chemical composition of food (pH, temperature, nutrients, etc.); (a) natural lost in producing amount; (b) producing the strain by phage of deactivation; (c) opposition effect of another microbial in foods product [39]. The usefulness of bacteriocin action in food is negatively affected by: (a) Resistance development of pathogens to the bacteriocin; (b) insufficient environmental situation for the living action; (c) Greater uses of the bacteriocin chemical reaction by food system components (e.g., fat); (d) deactivation by another additives; lower dissemination and dissolved and improper dispensation of bacte¬riocin chemical reaction in the meat matrix, [40]. Many factors, such as the occur of salts, other food ingredients, poor dissolved and the irregular dispensation of the bacteriocin, have all indicated to affect the effectiveness of bacteriocins in food, [41].

Conclusion

In principle of science, the most urgent problem is that there is still understanding of the efficacy of the utilize of traditional preserva-tives and naturally presenting antimicrobial biomolecules (biolog¬ical, natural preservatives) in coexistence with other major com¬ponents of food preservation system. The fermented food engages an important role in diet, human health and nutrition. The profit which are associated with fermentation are increased shelf life and able to continue for a long time, and nutritional value, Bacteriocins generated by LAB may become a potential drug candidate for re¬placing antibiotics so as to treat many drugs resistance pathogens in the future human health. An important of lactic acid bacteria for the food industry focus capability and authorization farther re¬search particularly in Africa, so as to increase the works of LAB genetically adapt LAB is being produced [42-62]. The establish¬ment of beneficial bacterial populations is preserved by traditional method such as freezing, curing fermenting; sugaring/salting, Dry¬ing, canning, smoking, and pickling are promoted. However, LAB based opposition do not importantly reduced feasible food safety issues in total, as they may be well planned only in a small range of food environment (pH, fat content, etc.) and this restrict their important in more food products. Thus, item-by-item deliberation of applying such a bio preservative to a sure unique nourishment matrix is essential.

Authors Contributions

KD is main author of the review; KK has a co-authored and super¬vised manuscript preparation, and helped to contribute in literature collection and editing of the review. All the two authors have read and approved the final manuscript.

Acknowledgments

The Ethiopian Institute of Agricultural Researches are highly thankful for supports us the network access, during the preparation of this manuscript.

Competiting Interest

The authors declare that they have no competing interests.

Availability of Data and Materials

Not applicable.

Consent for Publication

Not applicable.

Ethics Approval and Consent to Participate

Not applicable.

Funding

This review article was not supported by any funding agency.

References

1. Berk, Z. (2013). Food process engineering and technology. Academic press.
2. Jay, J. M. (2000). Modern food microbiology. Maryland.
3. Leniger HA., Beverloo WA. (2009). Food Process Engineer-ing. Netherlands: Springer.
4. Agrahar-Murugkar, D., & Jha, K. (2010). Effect of drying on nutritional and functional quality and electrophoretic pattern of soyflour from sprouted soybean (Glycine max). Journal of food science and technology, 47(5), 482-487.
5. George M., (2008). Food biodeterioration and preservation. In Tucker GS, editor. Blackwell Publisher: Singapore; 83.
6. Barbosa-Cánovas, G. V., Altunakar, B., & Mejía-Lorío, D. J. (2005). Freezing of fruits and vegetables: An agribusiness al­ternative for rural and semi-rural areas (Vol. 158). Food & Agriculture Org.
7. Meyer AS, Suhr KI, Nielsen P, Holm F, (2002). Natural food preservatives. In: Ohlsson T, Bengtsson N (Eds.) Minimal processing technologies in the food industry, chap 6. Wood­head Publishing; pp. 124–74.
8. Lee, S. Y., & Kang, D. H. (2004). Microbial safety of pickled fruits, vegetables, and hurdle technology. Internet Journal of food safety, 4, 21-32.
9. Msagati, T. A. (2012). The chemistry of food additives and preservatives. John Wiley & Sons.
10. Nummer, B. A., & Brian, A. (2002). Historical origins of food preservation. National Center for Home Food Preservation. University of Illinois Extension.
11. Brul, S., & Coote, P. (2020). Preservative agents in foods: mode of action and microbial resistance mechanisms. Interna­tional journal of food microbiology, 50(1-2), 1-17.
12. Gould G W. & Jones M V., (2018). Combination and syner-gistic effects in Mechanisms of action of food preservation. Edited by G W Gould (Elsevier Applied Science, London).
13. Kalchayanand, N., Sikes, A., Dunne, C. P., & Ray, B. (1998). Interaction of hydrostatic pressure, time and temperature of pressurization and pediocin AcH on inactivation of foodborne bacteria. Journal of food protection, 61(4), 425-431.
14. Nilsson, L., Hansen, T. B., Garrido, P., Buchrieser, C., Glaser, P., Knøchel, S., & Gravesen, A. (2005). Growth inhibition of Listeria monocytogenes by a nonbacteriocinogenic Carno-bacterium piscicola. Journal of Applied Microbiology, 98(1), 172-183.
15. Garcia, P., Rodriguez, L., Rodriguez, A., & Martinez, B. (2010). Promising strategies using bacteriocins, bacterio-phage and endolysins. Trends in Food Science & Technology, 21, 373-382.
16. Holzapfel, W. H., Geisen, R., & Schillinger, U. (2005). Bi­ological preservation of foods with reference to protective cultures, bacteriocins and food-grade enzymes. International journal of food microbiology, 24(3), 343-362.
17. Tagg, J. R., Dajani, A. S., & Wannamaker, L. W. (2016). Bac­teriocins of gram-positive bacteria. Bacteriological reviews, 40(3), 722-756.
18. Ray B., Y H Hui., & G Khachatourians. (2016). Pediococcus in fermented foods, in Food biotechnology microorganisms, Inc., New York), 745-796.
19. Ray B. & Miller K W. (2019). Pediocin: Natural food antimi­crobial systems (CRC Press, Boca Raton, FL), 525-566.
20. Dykes, G. A., & Moorhead, S. M. (2002). Combined anti­microbial effect of nisin and a listeriophage against Listeria monocytogenes in broth but not in buffer or on raw beef. In­ternational journal of food microbiology, 73(1), 71-81.
21. Hanlin, M. B., Kalchayanand, N., Ray, P., & Ray, B. (2013). Bacteriocins of lactic acid bacteria in combination have great­er antibacterial activity. Journal of Food Protection, 56(3), 252-255.
22. Cleveland, J., Montville, T. J., Nes, I. F., & Chikindas, M.L. (2001). Bacteriocins: safe, natural antimicrobials for food preservation. International journal of food microbiology, 71(1), 1-20.
23. Schillinger, U., Geisen, R., & Holzapfel, W. H. (2013). Poten­tial of antagonistic microorganisms and bacteriocins for the biological preservation of foods. Trends in Food Science & Technology, 7(5), 158-164.
24. De Vuyst, L. (2016). Production and applications of bacte­riocins from lactic acid bacteria: bioactive peptides for future food preservation.
25. Adams, M. (2009). Safety of industrial lactic acid bacteria. Journal of Biotechnology, 68(2-3), 171-178.
26. Rojo-Bezares, B., Saenz, Y., Navarro, L., Zarazaga, M., Ruiz-Larrea, F., & Torres, C. (2007). Coculture-inducible bac­teriocin activity of Lactobacillus plantarum strain J23 isolated from grape must. Food Microbiology, 24(5), 482-491.
27. Bennik, M., Smid, E. J., & Gorris, L. (2007). Vegetable-asso-ciated Pediococcus parvulus produces pediocin PA-1. Applied and Environmental Microbiology, 63(5), 2074-2076.
28. Bhat R., Alias AK. Paliyath G. (2012). Progress in food pres­ervation. Hoboken Wiley.
29. Bhunia, A. K., Johnson, M. C., Ray, B., & Belden, E. L. (2000). Antigenic property of pediocin AcH produced by Pediococcus acidilactici H. Journal of Applied Bacteriology, 69(2), 211-215.
30. Molinos, A. C., Abriouel, H., López, R. L., Valdivia, E., Omar, N. B., & Gálvez, A. (2008). Combined physico-chem-ical treatments based on enterocin AS-48 for inactivation of Gram-negative bacteria in soybean sprouts. Food and chemi­cal toxicology, 46(8), 2912-2921.
31. Delves-Broughton J. (2010). Nisin and its uses as a food pre­servative. Food Techno, 44; 100-117.
32. Devlieghere, F., Vermeiren, L., & Debevere, J. (2004). New preservation technologies: possibilities and limitations. Inter­national dairy journal, 14(4), 273-285.
33. Ennahar, S., Assobhei, O., & Hasselmann, C. (1998). Inhibi­tion of Listeria monocytogenes in a smear-surface soft cheese by Lactobacillus plantarum WHE 92, a pediocin AcH produc­er. Journal of food protection, 61(2), 186-191.
34. Galvez, A., Abriouel, H., Lopez, R., & Omar, N. (2007). Bac-teriocin-based strategies for food bio preservation. Interna­tional Journal of Food Microbiology, 120, 51-70.
35. Gonzalez, B., Arca, P., Mayo, B., & Suárez, J. E. (2004). De­tection, purification, and partial characterization of plantaricin C, a bacteriocin produced by a Lactobacillus plantarum strain of dairy origin. Applied and environmental microbiology, 60(6), 2158-2163.
36. Gross, E., Kiltz, H. H., & Nebelin, E. (2019). Subtilin, VI: the structure of subtilin (author's transl). Hoppe-seyler's Zeitschrift fur Physiologische Chemie, 354(7), 810-812.
37. Handbook of food preservation. (2007). Food science and technology. Boca Raton CRC Press.
38. Handbook of food preservation. (2009). New York, CRCPress 84. Brennan JG. Food processing handbook.
39. Hirsch, A., Grinsted, E., Chapman, H. R., & Mattick, A. T. R. (2001). 446. A note on the inhibition of an anaerobic spore-former in Swiss-type cheese by a nisin-producing streptococ­cus. Journal of Dairy Research, 18(2), 205-206.
40. Ivanovic, G. and Alfoldi, L (2003). A new antimicrobial prin-ciple. Megacin, Nature, 174, 1954, 465.
41. Jack, R.W., Tagg, J.R. and Ray, B. (2008). Bacteriocins of Gram-positive bacteria.
42. Klaenhammer, T. R. (2003). Genetics of bacteriocins pro­duced by lactic acid bacteria. FEMS microbiology reviews, 12(1-3), 39-85.
43. Lücke, F. K. (2000). Utilization of microbes to process and preserve meat. Meat science, 56(2), 105-115.
44. McCormick, J. K., Klaenhammer, T. R., & Stiles, M. E. (1999). Lactic acid bacteria can produce colicin V. Letters in Applied Microbiology, 29(1), 37-41.
45. McENTIRE, J. C., Montville, T. J., & Chikindas, M. L. (2003). Synergy between nisin and select lactates against Listeria monocytogenes is due to the metal cations. Journal of food protection, 66(9), 1631-1636.
46. Meghrous, J., Lacroix, C., & Simard, R. E. (1999). The effects on vegetative cells and spores of three bacteriocins from lactic acid bacteria. Food Microbiology, 16(2), 105-114.
47. Mulet-Powell N, Lactoste-Armynot A M, Vinas M & Simeon De Buochberg M (1998). Interactions between pairs of bacte­riocins from lactic acid bacteria, J Food Prot, 61; 1210-1212.
48. Nes, I. F. (2011). History, current knowledge, and future di­rections on bacteriocin research in lactic acid bacteria. Pro-karyotic Antimicrobial Peptides, 3-12.
49. Nilsen, T., Nes, I. F., & Holo, H. (2003). Enterolysin A, a cell wall-degrading bacteriocin from Enterococcus faecalis LMG 2333. Applied and environmental microbiology, 69(5), 2975-2984.
50. Nykänen, A., Weckman, K., & Lapveteläinen, A. (2000). Syn-ergistic inhibition of Listeria monocytogenes on cold-smoked rainbow trout by nisin and sodium lactate. International jour­nal of food microbiology, 61(1), 63-72.
51. Ogden K., Waites M J., & Hammond J R M., (2018). Nisinand brewing, J Inst Brew, 94; 233-238.
52. Peck, M. W. (2017). Clostridium botulinum and the safety of refrigerated processed foods of extended durability. Trends in Food Science & Technology, 8(6), 186-192.
53. Pilet, M. F., & Leroi, F. (2011). Applications of protective cultures, bacteriocins and bacteriophages in fresh seafood and seafood products. In Protective cultures, antimicrobial metab­olites and bacteriophages for food and beverage biopreserva-tion (pp. 324-347). Woodhead Publishing.
54. Pruthi, J. S. (1999). Quick freezing preservation of foods: foods of plant origin (Vol. 2). Allied Publishers.
55. Ryan, M. P., Flynn, J., Hill, C., Ross, R. P., & Meaney, W.J. (1999). The natural food grade inhibitor, lacticin 3147, re­duced the incidence of mastitis after experimental challenge with Streptococcus dysgalactiae in nonlactating dairy cows. Journal of Dairy Science, 82(10), 2108-2114.
56. Sanchis, M. R., Blanes, V., Blanes, M., Garcia, D., & Balart,R. (2006). Surface modification of low-density polyethylene (LDPE) film by low-pressure O2 plasma treatment. European Polymer Journal, 42(7), 1558-1568.
57. Schillinger, U., Geisen, R., & Holzapfel, W. H. (2016). Poten­tial of antagonistic microorganisms and bacteriocins for the biological preservation of foods. Trends in Food Science & Technology, 7(5), 158-164.
58. Shafia, F. (2016). Thermocins of Bacillus stearothermophilus.Journal of Bacteriology, 92(2), 524-525.
59. Srivatsa A N & Sankaran R, (2014). Preservation and packag­ing of tender coconut water in pouches and aluminium con­tainers, Indian Coconut J, 24; 54-56.
60. Ohara, T., & Suzutani, T. (2018). Efficacy of fecal microbiota transplantation in a patient with chronic intractable constipa­tion. Clinical Case Reports, 6(11), 2029.
61. Naidu, A. S. (Ed.). (2000). Natural food antimicrobial sys­tems. CRC press.
62. Weinheim., WILEY-VCH Verlag GmbH & Co. Kga., Ra-maswamy HS., Tung MA. (2006). A review on predicting freezing times of foods. J Food Process Eng. 7(3):169–203. 86