Application of active zein-based films with controlled release properties to control Listeria monocytogenes growth and lipid oxidation in fresh Kashar cheese

The antimicrobial and antioxidant potential of zein and zein-wax composite films having different release profiles for lysozyme and mixture of lysozyme, catechin and gallic acid were tested on cold-stored fresh Kashar cheese inoculated with Listeria monocytogenes ATCC 7644. All lysozyme containing films prevented the increase of L. monocytogenes counts in Kashar cheese for 8 weeks at 4 degrees C, but it was only the zein-wax composite films with sustained lysozyme-release rates which caused a significant reduction (-0.4 decimals) in initial microbial load of inoculated cheese samples. The mixture of catechin and gallic acid improved the in vitro antimicrobial effect of films against L. monocytogenes, but showed no considerable antimicrobial effect in cheese. However, the films containing catechin and gallic acid were effective in preventing oxidative changes in cheese. This study showed the possibility of increasing safety and quality of fresh cheeses by use of active packaging employing natural antimicrobial compounds and controlled release technology.