Fabrication of sustainable composite films based on chitosan/deep eutectic solvent/tannic acid quantum dots for bioactive pork preservation

Abstract

In this work, a sustainable composite film was fabricated by incorporating citric acid/betaine-based deep eutectic solvent (DES) into a chitosan/tannin acid quantum dots (CS/TAQDs) matrix. The addition of DES increased the interfacial bonding compatibility between CS and TAQDs, and thus the tensile strength and elongation at break of composite film were significantly improved. This composite film exhibited excellent UV barrier capacity and antioxidant capacity with 2,2-diphenyl-1-picrylhydrazyl free radical scavenging rate of 97.8%. It showed outstanding antibacterial performance against Staphylococcus aureus and Escherichia coli, which can be used for pork preservation. The total volatile base nitrogen test demonstrated that the pork preservation by CS/DES/TAQDs composite film showed lower TVB-N value than commercialized polyethylene film. The pork shelf-life can be prolonged to 7 days in 4℃. This composite film can be completely biodegraded within 7 days in natural environment, suggesting the great application potential in food packaging field.