Ag@MOF-loaded p-coumaric acid modified chitosan/chitosan nanoparticle and polyvinyl alcohol/starch bilayer films for food packing applications

Developing novel bilayer food packing film having the ability to prevent bacterial infections and capable of inhibiting oxidation is utmost important, since bacterial infections and oxidation can cause food spoilage. Ag-Metal−organic framework loaded p-coumaric acid modified chitosan (P-CS/Ag@MOF) or chitosan nanoparticles (P-CSNPs/Ag@MOF) and polyvinyl alcohol/starch (PVA/ST) were used as the upper film and lower layer film to successfully prepare a bilayer composite film. The microscopic morphology, water resistance, oil resistance, oxidation resistance, optical properties, cytotoxicity and antibacterial properties of the composite films were compared. The results showed that the surface of P-CS/Ag@MOF bilayer was relatively smooth and its tensile strength (TS) was higher (27.67 MPa). Among them, P-CS/Ag@MOF bilayer films had better oil resistance and oxidation resistance activity. In addition, the P-CS/Ag@MOF bilayer film had good UV-blocking properties and transparency. P-CSNPs/Ag@MOF bilayer film had higher antibacterial activity and cytotoxicity.