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J. M. KROCHTA1, S. Min1, and J. H. Han2. (1) Dept. of Food Science & Technology, Univ. of California, Davis, 1 Shields Ave., 237 Cruess Hall, Davis, CA 95616, (2) Dept. of Food Science, Univ. of Manitoba, Ellis Bldg., Winnipeg, MB R3T 2N2, Canada Edible coatings are being investigated for many important functions, including protection from oxidation or moisture change, prevention of physical damage, and enhancement of product appearance. By incorporating antimicrobials, the functionality of edible coatings can be extended to enhance food safety and extend product shelf-life. Thus, edible coatings containing bioactive agents can provide an additional hurdle to enhance the utilization of non-thermal preservation techniques. Several factors influence the type of edible coating material selected, including food properties (pH, water activity and composition) and processing and storage conditions. Coating materials that are currently used include lipids (oil, waxes, emulsions), resins (shellac, rosin), carbohydrates (celluloses, pectins, chitin, starches, gums) and proteins (milk, soy, collagen/gelatin, wheat, corn, peanut). Additionally, plasticizers, emulsifiers or surfactants may be added to enhance the coating. In choosing an antimicrobial, the effectiveness against the target microorganism is the primary consideration. Antimicrobial interactions with the coating material, food and environment must also be considered. Current antimicrobials include: organic acids (acetic, benzoic, lactic, proprionic, sorbic), fatty acids, parabens, bacteriocins (nisin), sulfites, sucrose esters, and other natural antimicrobials (natamycin, lactoferrin, lysozyme, lactoperoxidase). Because of these many factors, current research on antimicrobial edible coatings ranges from experiments that test antimicrobial-activity to experiments that investigate product-specific applications. Requirements for a useful antimicrobial coating include: practical food-application procedure, good adhesion and interaction with the food product, antimicrobial effectiveness and controlled migration of the antimicrobial. Evaluation of these requirements is key to success, and many experimental methods are in use. Increased understanding of coating properties will allow design of edible antimicrobial coatings for foods that are processed using non-thermal methods.
Session 57, Active packaging for non-thermal processing
2005 IFT Annual Meeting, July 15-20 - New Orleans, Louisiana |