Self-reinforced multifunctional starch nanocomposite film for litchi fruit postharvest preservation

Consumers enjoy fruit because of its delicious flavor and nutritional value. However, fruit is also prone to oxidation and microbial infection after picking. Therefore, it is imperative to produce safe antiseptic packing materials. Starch films have received considerable attention as an alternative to conventional plastics. The addition of other antibacterial active materials to starch film can significantly improve performance, including water resistance, anti-oxidation, and antibacterial properties. Selenium nanoparticles (SeNPs) have exceptional anti-oxidation and antibacterial characteristics and are therefore considered effective antibacterial agents. In this study, we utilized polyphenol and polysaccharide interactions to improve the structure-biological activity of SeNPs to introduce anti-oxidation, antibacterial properties, and UV-blocking performance to extend the shelf life of food and achieve self-reinforcement, thus improving the mechanical properties of the material and making it suitable for food packaging. Notably, the process for the preparation of the SeNPs-embedded starch film was environmentally friendly (water as the solvent) and simple, with mild reaction conditions. The results from this study demonstrated the ability of starch film to reduce dehydration, prevent nutrient loss, inhibit microbe growth, preserve litchi quality, and extend the shelf life during storage. In addition, the film demonstrated biodegradability (11 days in soil), good biocompatibility, and biosafety, offering significant potential for the development of safe and sustainable food packaging systems. This phytochemical nano-enhancement starch film offers a promising solution for multipurpose active food packaging.