Antibacterial Chitosan-Gelatin Microcapsules Modified with Green-Synthesized Silver Nanoparticles for Food Packaging

Silver nanoparticles (Ag NPs) are an effective antibacterial agent, but their application in food packaging is limited due to their easy agglomeration and oxidation. In this study, antibacterial microcapsules were fabricated using Ginkgo biloba essential oil (GBEO) as core material and chitosan and type B gelatin biopolymer as capsule materials. These antibacterial microcapsules were then modified with green-synthesized Ag NPs, blended into the biopolymer polylactic acid (PLA), and finally formed as films. Physicochemical properties and antibacterial activity against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) were evaluated. Results showed that the prepared antibacterial PLA films exhibited excellent antibacterial activity against foodborne pathogens. Its TVC exceeded the limit value of 7 log CFU/g at 7 days compared with the 5 days of pure PLA films. Therefore, these films can extend the shelf life of grass carp fillets by 2-3 days under refrigeration.