Zein/chitosan Janus film incorporated with tannic acid and cinnamon essential oil co-loaded Pickering emulsion for sustained controlled release and pork preservation.

The development of active packaging offers a promising approach to reducing food waste. However, challenges remain, particularly in achieving efficient release dynamics of active compounds and balancing the barrier properties. Herein, a Janus structure zein/chitosan film is custom designed by layer-by-layer casting method to achieve sustainable and unidirectional release performance of antimicrobial agent, which comprises an inner loading layer of tannic acid (TA) and cinnamon essential oil (CEO) co-loaded Pickering emulsion incorporated with chitosan and an outer barrier layer of zein. The good interfacial compatibility between the entities of Pickering emulsion/chitosan loading layer and zein barrier layer had be confirmed via physicochemical structure characterization. The lower swelling rate of Pickering emulsion/chitosan film (47.61 %-51.71 %) indicated the sustained and stable release rate of substances from the inner loading layer, while the zein barrier layer restricted the diffusion of active molecules due to the high swelling rate (162.52 %). In addition, the films showed excellent antimicrobial activity (>99 % against key foodborne pathogens) and radical scavenging activity (2.5-fold enhancement). Moreover, the film loading layer showed predominantly controlled by a quasi-Fickian diffusion, and prolonged the shelf life of pork by 6 days under the unidirectional sustained release. Our work presents a promising fabrication strategy of antimicrobial packaging film with sustainable release performance for food preservation.