Characterization of chitosan/eugenol-loaded IRMOF-3 nanoparticles composite films with sustained antibacterial activity and their application in postharvest preservation of strawberries

In this work, we prepared chitosan/eugenol-loaded IRMOF-3 nanoparticles (CS/IRMOF-3-EU) composite films using (0, 2, 4, and 6 wt%) isoreticular metal-organic framework (IRMOF-3) nanoparticles loaded with eugenol (IRMOF-3-EU), co-blended with chitosan to develop environmentally friendly food packaging materials with sustained antimicrobial activity. The microstructure and physicochemical properties of the composite films were investigated. The addition of IRMOF-3-EU to the CS matrix significantly enhanced the UV-blocking property and elongation at the break of the composite films; the CS/IRMOF-3-EU composite films inherited the antioxidant and antibacterial properties of eugenol (EU), and the DPPH radical scavenging ability was increased to 53.8% with the addition of 6% IRMOF-3-EU, while it showed excellent antibacterial ability; in addition, the CS/IRMOF-3-EU composite films achieved the sustainable release of eugenol to achieve the long-lasting antibacterial effect. Experiments on strawberry preservation applications showed that the CS/IRMOF-3-EU films slowed down the deterioration of strawberry quality, delayed the decline of hardness, effectively suppressed weight loss, H2O2 content, and malondialdehyde content, and delayed the decline of catalase activity and peroxidase activity. It showed that the CS/IRMOF-3-EU composite films could be used to maintain the postharvest quality and prolong the shelf life of strawberries.