Natural Food Preservatives

Surjakanta, Phijam (2008) Natural Food Preservatives. [Student Project Report]

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Abstract

This Dissertation / Report is the outcome of investigation carried out by the creator(s) / author(s) at the department/division of Central Food Technological Research Institute (CFTRI), Mysore mentioned below in this page.

Item Type:	Student Project Report
Additional Information:	Natural food preservatives as the name indicates are naturally available in plants, animals and microorganisms. Their preservative properties are due to the antimicrobial and antioxidant compounds. Antimicrobial sources are from plants (secondary metabolites in phytoalexins and essential oils from herb/spices), animals ( egg lysozyme and transferrins from milk), microorganisms (nisin, bacteriocin, natamycin, lactic acid). Bacteria are a source of antimicrobial peptides, which have been examined for applications in microbial food safety. Among the Gram-positive bacteria, the lactic acid bacteria have been comprehensively exploited as a reservoir for antimicrobial peptides with food applications. The antimicrobial proteins or peptides produced by bacteria are termed bacteriocins and have been shown to be safe, and have potential as effective natural food preservatives. Although many bacteriocins have been isolated and characterized, only a few have demonstrated commercial potential in food application. Many lactic acid bacteria LAB produce a high diversity of different bacteriocins. Though these bacteriocins are produced by LAB found in numerous fermented and non-fermented foods, nisin is currently the only bacteriocin widely used as a food preservative. Many bacteriocins have been characterized biochemically and genetically, and though there is a basic understanding of their structure–function, biosynthesis, and mode of action, many aspects of these compounds are still unknown. Antimicrobials will undoubtedly continue to be needed to provide the food supply that will be demanded in the future. Natural antioxidants are those phenolic or polyphenolic compounds commonly occurring in plant materials, which interfere with the formation of free radicals (i.e., the initiation reactions) and also deter the propagation of oxidation or the free radical chain reactions, thus preventing formation of hydroperoxides. In general, antioxidants provide primary defense to the bodily system by eliminating free radicals which interfere with metabolism. It is well known that some antioxidants occur naturally in different amounts in all foods and herbal medicines. The superiority of natural antioxidants has been proven over synthetic ones in terms of safety, tolerance, and non toxicity, without any side effects, because these components occur naturally in foods which have been consumed for years. In general, synthetic food additives are subjected to pharmacological scrutiny and technical evaluation for mutagenic, carcinogenic, and pathogenic effects. Such toxicity concerns, in addition to consumers’ preference for “all natural” ingredients and stringent regulations in developed countries, have resulted in increased interest in natural antioxidants. Most commonly used natural antioxidants are tocopherols, ascorbic acid, flavonoids, lecithin, citric acid, and polyphenols. These are added in minute, predetermined concentrations (0.01 to 0.02%) to oils, sterols, emulsifiers, fat-soluble vitamins, phospholipids, flavors, aroma, even carotenoids (color) that are susceptible to oxidation during storage and transportation. Hence, antioxidants are essential for maintaining a good state of health for our body system and for the preservation of foods and medicines. While the natural preservatives are still in their nascent state, the antioxidants are much more advanced and do have a large market share. Further, more fundamental knowledge of the mechanism of action of the natural preservatives is needed in order to set up an effective preservation strategy for each product type. For this reason, much more research on shielding and complexing factors from the food matrix is needed. The natural concept is not only limited to preservatives and antioxidants. New challenging research areas are natural enzyme inhibitors to delay the enzymatic deterioration and improved selective and natural complexing agents, e.g. influencing vital functions of microorganisms or stabilising food texture.
Uncontrolled Keywords:	Natural food preservatives Antimicrobial sources Bacteria lactic acid bacteria
Subjects:	600 Technology > 08 Food technology > 31 Food Additives
Divisions:	Human Resource Development
Depositing User:	Food Sci. & Technol. Information Services
Date Deposited:	12 May 2009 09:21
Last Modified:	12 May 2009 09:21
URI:	http://ir.cftri.res.in/id/eprint/8942

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