Development of gelatin-based antibacterial composite films incorporating dialdehyde starch and AgNPs@MXene for active food packaging

The application of gelatin (GEL)-based films in food packaging is limited by poor mechanical strength, high water sensitivity, low gas barrier properties, and lack of antibacterial activity. In this study, dialdehyde starch (DS) and AgNPs-immobilized MXene nanosheets (AgNPs@MXene) were incorporated into GEL to fabricate active packaging films. The strong interfacial interactions and compact structure significantly enhanced the films' physicochemical properties. Compared with pure GEL, the GEL/DS/AgNPs@MXene-5 film showed a 96.33 % increase in tensile strength, a 391.59 % increase in elongation at break, and reductions of 62.33 %, 71.62 %, and 71.13 % in water solubility, water vapor, and oxygen permeability, respectively. Additionally, it exhibited >90 % antibacterial activity against S. aureus and E. coli , attributed to the synergistic effect of AgNPs and photothermal MXene, while maintaining good biosafety and biodegradability. Packaging tests confirmed its effectiveness in preserving the post-harvest quality of Tricholoma matsutake and maintaining pork freshness, demonstrating great potential for active food packaging.