Antibacterial chitosan/silver nanoparticles films for food packaging: A review

Chitosan is a renewable, biodegradable, and film-forming polysaccharide with intrinsic antibacterial activity, making it a promising matrix for food packaging applications. The introduction of silver nanoparticles (AgNPs) can further enhance the antibacterial performance of chitosan films, thereby improving their effectiveness in food packaging applications. Nevertheless, the antibacterial activity of the fabricated chitosan/AgNPs films largely depends on the formation, dispersion, and availability of AgNPs within the chitosan matrix. This review summarizes recent progress in chitosan/AgNPs films, focusing on fabrication strategies, antibacterial activity, and food preservation applications. There are two major fabrication strategies for the preparation of chitosan/AgNPs films, such as the one-pot synthesis (AgNPs are directly formed in situ within the chitosan matrix) and the two-step synthesis (AgNPs are pre-synthesized and then blended with the chitosan matrix). The antibacterial activity of the chitosan/AgNPs films can be regulated by adjusting the relative content and particle size of the incorporated AgNPs. Chitosan/AgNPs films are currently being applied for various food packaging applications, such as fruits, meats, seafood, and bakery foods. Overall, this review can provide guidance for the controllable preparation of chitosan/AgNPs films and the optimization of their antibacterial activity, thereby laying the foundation for their development as active food packaging materials.