Application of polyvinyl alcohol-chitosan composite antimicrobial coating agent in preservation of fresh eggs

The effects of polyvinyl alcohol-lysozyme composite coating on the freshness of eggs were studied. The content of polyvinyl alcohol was optimized by water vapor transmission and water retention as the filming indexes. The 9 g/100 mL PVA was selected to be rematched with lysozyme of 0.03,0.06,0.09,0.12 g/100 mL. In order to screen out the best ratio of polyvinyl alcohol and lysozyme,the eggs in the coated and uncoated control groups were tested at room temperature with the weight loss rate,huff unit,egg yolk index,pH,volatile salt nitrogen,microbial and other indicators.The results showed that 0.03 g/100 mL lysozyme and 9 g/100 mL polyvinyl alcohol ratio of the coating agent was better than that of other concentrations on the freshness of eggs.Eggs stored at room temperature for 45 days,yolk index was 0.26,56.1% higher than the uncoated eggs the lowest weight loss rate was 5.61%,98.9% lower than the uncoated film,the Hough unit was 68,25% higher than the uncoated. PH was 9.02,5% lower than the uncoated. Volatile base was 4.98 mg/100 g,86% lower than the uncoated. It is indicated that polyvinyl alcohol-lysozyme composite coating was not only anti-bacterial,but also good film and safe environment. Eggs were kept fresh at normal temperature.