Self-Reinforced and Antibacterial Zn2+ @Vanillin/Carboxymethyl Chitosan Film for Food Packaging

Polysaccharide-based films cannot replace petroleum-basedfoodpackaging due to their poor mechanical properties, and the lack ofantibacterial properties also makes it difficult to extend the foodshelf life. Herein, we used the Schiff base reaction and zinc ion(Zn2+) complexation on carboxymethyl chitosan (CMCS) chainsto introduce antibacterial properties to extend the shelf life offood and achieved self-reinforcement to improve mechanical properties,reaching 7.28 MPa and making it suitable for food packaging. The Zn2+@Vanillin (VA)/CMCS film possessed broad-spectrum antibacterialproperties that extended the shelf life of fruits and offered betterthermal stability and water vapor barrier. Besides, it also providesmore comprehensive protection and inhibits the respiration of fruitsduring the preservation process that maintains the quality of thefruits. In addition, the process for the preparation of the Zn2+@VA/CMCS film was environmentally friendly (the solvent iswater), safe, and simple and had mild reaction conditions. Noteworthily,the Zn2+@VA/CMCS film possessed biodegradability (35 daysin soil) and renewable characteristics that offer significant potentialfor the development of sustainable food packaging systems. The preparation process and mechanismof the self-reinforcedand antibacterial Zn2+@vanillin/carboxymethyl chitosanfilm for sustainable food packaging systems.