On-demand cinnamaldehyde releasing from gelatin-based active hydrogel activated by lactic acid for pork meat preservation: A novel “one-step-ahead” strategy

Fresh pork meat usually experiences “acid-expelling” and “biogenic amine releasing” stages during the storage period. Traditional on-demand releasing process of active packaging was activated by alkaline gas within packaging microenvironments in latter stage, whereas the research on lactic acid-induced releasing stage was ignored. Herein, a polyvinyl alcohol–based preserving system was designed to prolong the shelf life of pork using a “one-step-ahead” strategy. The breakage of imine bonds in acidic conditions resulted in the release of active cinnamaldehyde when triggered by the produced lactic acid after slaughter. The periods of “post ripening” and “autolysis” stage were prolonged about 75 % and 100 %, respectively, extending the shelf life of pork meat 5 days at ambient conditions. Furthermore, the optimized polyvinyl alcohol(gelatin@cinnamaldehyde)/boric acid-5 % exhibited reinforced mechanical behaviors, antioxidant and antibacterial performances. This finding deepened the in-depth understanding of advanced design concept about on-demand active packaging from the intrinsic physicochemical parameters' evolution of foods during storage period.