Preparation and characterization of active chitosan based films containing oregano essential oils loaded Cu/MOFs

The purpose of this study is development of novel antimicrobial and antioxidant films using copper metal-organic frameworks (Cu-MOFs) loaded into chitosan-based (CH) films infused with oregano essential oil (OEO) for food packaging. Chitosan-based films incorporating oregano essential oils loaded Cu/MOFs at different levels (1 wt%, 2 wt% and 3 wt%) were successfully elaborate by casting method to improve the tensile strength, barrier, antimicrobial and antioxidant properties of the films. The SEM results indicated that the Cu-MOFs were uniformly distributed in the CH matrix, leading to improvement in functional properties, including mechanical and thermal properties, UV-light protection, and water vapor barrier capability of the developed composite films. In addition, the resultant CH/Cu-MOFs composite films revealed higher antibacterial and antioxidant activities. The combination of OEO and Cu-MOFs demonstrated strong antioxidant activity, achieving 76% efficacy against 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals. Cu-MOFs-loaded chitosan film showed superior antibacterial function against Gram-positive (S. aureus) and Gram-negative (E. coli) bacteria, and fungi (Penicillium digitatum). According to the obtained results, it is suggested that developed CH/OEO/Cu-MOFs films could offer great potential as active packaging to maintain the food quality.