Antibacterial film with chitosan-cinnamaldehyde Schiff base: Fabrication and application in chilled mutton preservation

Abstract

Release in response to stimuli such as enzyme, pH, temperature, and light effectively reduces the loss of volatile active compounds and controls the release of active ingredients. In this study, a Schiff base imine bond was formed between chitosan and cinnamaldehyde under mild conditions, and a pH-sensitive antimicrobial film was prepared using a chitosan matrix. The mechanical and physical properties, structure, and amount of cinnamaldehyde release from the chitosan-cinnamaldehyde Schiff base film were analysed, confirming the formation of a chitosan-cinnamaldehyde Schiff base. The film demonstrated good physical properties as well as pH-responsive sensitive release properties with excellent antimicrobial activity. Experiments on the freshness preservation of chilled mutton wrapped in the chitosan-cinnamaldehyde Schiff base film showed that the film can extend the preservation time at 4 °C for up to 4 days, demonstrating good water retention. This film accomplished the controlled release of cinnamaldehyde, meeting the requirements for meat preservation. Thus, the chitosan-cinnamaldehyde Schiff base film can be used as an eco-friendly, smart, responsive, controlled-release packaging material for chilled mutton.