Due to the serious environmental pollution generated by plastic packaging, chitosan (CS)-based biodegradable films are gradually gaining popularity. However, the limited antioxidant and bacteriostatic capabilities of CS, the poor mechanical properties and water resistance of pure CS films limit their widespread adoption in food packaging. In this study, new multifunctional bioactive packaging films containing monosaccharide-modified CS and polyvinyl alcohol (PVA) were prepared to address the shortcomings of pure CS films. Initially, Maillard reaction (MR) products were prepared by conjugating chitosan with galactose/mannose (CG/CM). The successful preparation of CG/CM was confirmed using UV spectroscopy, fluorescence spectroscopy, fourier transform infrared spectroscopy (FTIR) and high-performance gel permeation chromatography (HPGPC). At an 8 mg/mL concentration, the DPPH radical scavenging activities of CM and CG were 5 and 15 times higher than that of CS, respectively. At the maximum concentration of 200 mu g/mL, both CM and CG exhibited greater inhibitory effects on the growth of Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli, compared to CS. Additionally, CM and CG demonstrated significantly stronger protection against oxidative damage in Vero cells than CS. These results indicate that CG and CM possess superior antioxidant and antibacterial capabilities in comparison to CS. Then, the effects of the MR on the structures and functional properties of chitosan-based films were extensively examined. Compared with pure CS films, the MR in the CG/CM films significantly changed the film microstructure, enhanced the UV-barrier property and water resistance, and only slightly reduced thermal stability. The MR reduced the tensile strength but increased the elongation at break. Meanwhile, the composite films hold good soil degradation ability. Moreover, the CG/CM films possessed excellent antioxidant and antibacterial properties and demonstrated superior fresh-keeping capacity in the preservation of strawberries and cherry tomatoes (effectively prolonged for at least 2 days or 3-6 days). Our study indicates that CG/CM films can be used as a promising biodegradable antioxidant and antibacterial biomaterial for food packaging.

来源平台：FOOD HYDROCOLLOIDS