Preparation and characterization of zeolite imidazole framework-8@quercetin nanoparticle/sodium alginate/L-cysteine/calcium ion hydrogel films for fruit preservation

This study incorporated quercetin into the zeolite imidazole framework-8 (ZIF-8) to form ZIF-8@Quercetin nanoparticles (ZIF-8@Que), which were subsequently integrated into a matrix comprising sodium alginate (SA), L-cysteine (Cys). Hydrogel films were fabricated via solution casting and calcium ion (Ca 2+ ) cross-linking. The incorporation of 15% ZIF-8@Que. remarkably improved the light-blocking performance of the hydrogel film. Additionally, the water content and dissolution rate were 81.36% and 55.34%, respectively. The elongation at break of the film improved substantially from 62.60% to 78.04%, whilst its antioxidant capacity enhanced to 48.80%. The antibacterial activities of the hydrogel films were equally enhanced, by log reduction against E. coli at 1.47 and against S. aureus at 1.06. In fruit preservation tests, hydrogel films containing 15% ZIF-8@Que. extended the shelf life of apple as well as pineapple slices. These results suggest that ZIF-8@Que-loaded hydrogel films show potential as an alternative to traditional preservation materials. • Zeolite imidazole framework-8 (ZIF-8) loaded with quercetin formed the ZIF-8@Quercetin nanoparticle. • The hydrogel films demonstrated exceptional barrier properties, antibacterial activity, antioxidant capacity, and biosafety. • The hydrogel film underwent a structural transition from ionic cross-linking to multiple physical cross-linking mechanisms. • The hydrogel films significantly improved the freshness retention of apple and pineapple slices and exhibited significant potential as a food packaging material.