Preparation of composite film incorporating pomegranate peel polyphenols/ginger essential oil/sodium alginate/Nano TiO2 and its application in post-harvest grapes preservation

A composite film was prepared using sodium alginate as the substrate, supplemented with nano-TiO₂ and antimicrobial agents consisting of pomegranate peel polyphenols and ginger essential oil at different ratios. The film was fabricated via cast-film method as a pomegranate peel polyphenol/ ginger essential oil/sodium alginate/nano-TiO₂ composite. Its properties were characterized, and the film's effects on grape storage quality indicators were evaluated. The results showed the P6 composite film exhibited optimal mechanical properties, with a tensile strength of 6.13 MPa and an elongation at break of 200.88%. Its soil degradation rate reached 10.74% after 15 d. It effectively suppressed quality loss in grapes and significantly reduced rot rates, while better maintaining hardness, ascorbic acid content, soluble solids content, and titratable acidity, thereby extending the grape storage life. This study demonstrates that the composite film extends fruit shelf life, reduces packaging costs for greater economic benefit, and minimizes packaging waste and plastic pollution, offering significant environmental advantages.