Chitosan/gelatin-based film activated by Pickering emulsion of citrus essential oil stabilized by esterified starch/whey protein isolate fibrils: Application in preserving freshness of blueberry

This study used chitosan (CS) and gelatin (GL) as base materials and employed emulsion encapsulation technology to prepare films with citrus essential oil (CEO) as an antimicrobial agent. The results showed that the CEO emulsion was uniformly distributed throughout the interior and surface of the film, promoting the formation of a thicker and rougher layered porous structure, which significantly improved the film's elongation at break and water resistance. Additionally, the addition of the CEO emulsion significantly improved the film's thermal stability, enhanced its UV resistance, antioxidant properties, and antibacterial performance. In practical applications, the CG/WO-7 % composite film inhibited the respiration of blueberries, reduced weight loss and nutrient loss, enhanced their antioxidant enzyme activity, and suppressed the excessive accumulation of ROS. Compared with the control group, the treatment with CG/WO-7 % film extended the shelf life of blueberries by 3 days, from 5 days to 8 days.