Active packaging of ground beef patties by edible zein films incorporated with partially purified lysozyme and Na(2)EDTA

P>In this study, antimicrobial activity of zein films incorporated with partially purified lysozyme and disodium ethylenediaminetetraacetic acid (Na(2)EDTA) has been tested on selected pathogenic bacteria and refrigerated ground beef patties. The developed films containing 700 mu g cm-2 lysozyme and 300 mu g cm-2 Na(2)EDTA showed antimicrobial activity on Listeria monocytogenes, Escherichia coli O157:H7, and Salmonella typhimurium. The application of lysozyme and Na(2)EDTA incorporated zein films on beef patties significantly decreased total viable counts (TVC) and total coliform counts after 5 days of storage compared to those of control patties (P < 0.05). Zein films incorporated with lysozyme and Na(2)EDTA or Na(2)EDTA alone significantly slowed down the oxidative changes in patties during storage (P < 0.05). Redness indices of patties coated with zein films were significantly lower than those of uncoated control patties during storage (P < 0.05). This study demonstrated the potential usage of zein films containing lysozyme and Na(2)EDTA for active packaging of refrigerated meat products.