Eugenol-loaded functionalized TiO₂-reinforced chitosan-guar gum-based films with photocatalytic sterilization for active food packaging application

A biodegradable food packaging film was fabricated using nano ZnO/Nitrogen-Doped nano TiO₂ and Eugenol composite (ZTE), by incorporating different concentrations of ZTE into chitosan guargum (CG/ZTE) films. Compared to pure CG films, the nanocomposite films showed improved tensile strength, thermal stability, moisture resistance, and excellent UV shielding properties. In normal condition, the composite film exhibited excellent antibacterial activity in multiple bacterial strains such as E. coli, P. aeruginosa, S. aureus and B. subtilis. However, when irradiated under 450 nm visible light, the films showed strong antibacterial activity against S. aureus and E. coli within 30 min via photo-catalytically produced reactive oxygen species (•OH). The nanocomposite film inhibited biofilm formation by over 94 % against S. aureus and 88 % against E. coli within 72 h. The shelf-life of wrapped chicken fillets in CG/ZTE films was extended to 12 days when sterilized under visible light, compared to 6 days for unwrapped fillets. The weight loss of the composite film was more than 50 % in soil within 30 days. It showed excellent biocompatibility with L929 cells, making them suitable for food contact applications. Therefore, the composite film possessed all the desired features to be considered an active biodegradable food packaging material for industrial use.