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J. H. HOTCHKISS, Dept. of Food Science, Cornell Univ., 119 Stocking Hall, Ithaca, NY 14853-7201 Polymers used for food contact are chosen, in part, for their inertness and lack of direct interaction with foods, among other attributes. Polymers such as low density poly(ethylene) (LDPE) and poly(propylene) (PP) can be considered inert from the viewpoint of foods but this property does not allow for attachment of bioactive compounds such as enzymes and antimicrobials that may be useful in food contact surfaces. Attachment could be beneficial in that the active compounds would likely not become part of the food and act only at the food-polymer interface. They may also have increase stability. We have studied the modification of polymer surfaces in order to make them more functional. For example, we have surface oxidized LDPE in order to add functionality. We then grafted polymers such as poly(ethylene glycol) (PEG) and poly(ethylene imine) (PEI) to the surface using aqueous-based chemistries. The numbers of active sites per unit area were determined using specific dye binding assays. Changes in surface hydrophobicity due to oxidation and grafting were measured by contact angle. Spectral analyses were used to confirm the grafting procedures. These grafted polymers where then covalently attached to bioactive molecules such as lactase and antimicrobial peptide. Lactase was attached but not active while the antimicrobial peptide retained activity. This presentation will focus on the chemistry of functionalization of these polymers and the activity of the resulting materials.
Session 57, Active packaging for non-thermal processing
2005 IFT Annual Meeting, July 15-20 - New Orleans, Louisiana |