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<OL> <LI> Develop antimicrobial packaging materials that can deliver an antimicrobial additive to the food surface through contact with the packaging material. Biopolymers or combinations of biopolymers with synthetic materials will be used. <LI> Measure effectiveness of antimicrobial packaging materials in non-food and food systems.
Work will focus on cellulose-based coatings on synthetic films. The coating will carry nisin (FDA approved for cheese). Four diferent densities of cellulose will be usd to determine if nisin diffuses more effectively at high viscosity or low viscosity. Effectiveness of nisin will be determined by placing coated films on agar inoculated with Listeria monocytogenes and examining plates for zones of inhibition.Once the optimal level of nisin and cellulose viscosity has been established, organic acids and EDTA will be added to the cellulose coating to increase the effectiveness of nisin. This combination will also be tested using agar plates inoculated with L. monocytogenes and examined for zones of inhibition. This will establish the optimal combination of nisin, organic acid, EDTA, cellulose viscosity to test with a food system. Shredded cheddar cheese will be inoculated with Listeria monocytogenes, packaged in the antimicrobial film and stored at refrigeration temperature. Cheese will be analyzed for reduction of microbial growth during storage. The physical characteristics of the films will also be measured. Other studies will use monolayer biopolymeric films as carriers of antimicrobial additives with similar tests performed to determine their effectiveness.
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Ultimately the goal of this work is to develop an effective antimicrobial packaging film that can extend the shelf life and reduce growth of pathogenic bacteria in food.</p>