Highly stable and multifunctional intelligent film based on grape skin anthocyanin, polyvinyl alcohol, chitosan and selenopeptide: Preparation, characterization and application

Highly stable and multifunctional intelligent films were fabricated using a combination of grape skin anthocyanin, polyvinyl alcohol, chitosan and selenopeptide, and the influence of selenopeptide concentration on films' properties and their effectiveness in strawberry preservation and freshness monitoring was investigated. The results showed that the incorporated selenopeptide could interact with polyvinyl alcohol and grape skin anthocyanin via hydrogen bonding, improving the hydrophobic, UV-blocking, and mechanical characteristics of the films. In particular, the introduction of 0.4% selenopeptide into the film notably boosted its tensile strength from 11.91 MPa to 26.91 MPa. More importantly, the films incorporated with selenopeptide showed decent antioxidant and antibacterial properties, along with high storage stability and thermal stability. Adding 0.4% selenopeptide to the film can increase the shelf life of strawberries at 25 degrees C by 3 days, and a distinct color change showing fair good linear relationship with the freshness indexes of the strawberry (hardness and weight loss rate) was observed. Overall, anthocyanin-infused films combined with selenopeptide have demonstrated promising results in preserving food and monitoring freshness, opening up new opportunities for preparing stable, smart and active films.