Functional properties and release characteristics of tea polyphenols-loaded gliadin films enforced by cinnamaldehyde

Protein-based packaging is beneficial for preserving the freshness of foods and extending their shelf-life. How-ever, their mechanical and water-resistant properties limit their further usage. Herein, the gliadin was cross-linked by cinnamaldehyde (CA) and achieved by adding tea polyphenols (TPs) for active packaging. The physicochemical properties, functionalities, and TPs-release behavior were investigated. The results showed that the TPs-loaded gliadin films performed UV resistance and anti-digestion properties; the addition of 33 g/kg TPs had no effect on their mechanics, but increased their water content and improved their antioxidant properties. The CA crosslinking not only advanced the TPs-loading capacity but also improved the TPs release properties of the films, which showed a slow-release effect. Meanwhile, the release order of TPs from the films was acidic food-simulated solution, alcoholic food-simulated solution, fatty food-simulated solution, and common food-simulated solution. Consequently, the gliadin films could be ideal material for loading TPs and their film properties could also enforce by CA.