Overcoming mechanical and moisture barriers: A novel rice protein/sodium alginate packaging film based on gelatin and...

Rice protein/sodium alginate films typically exhibit deficient mechanical strength and moisture resistance. This study fabricated a composite film by incorporating gelatin and polydimethylsiloxane (PDMS). At a rice protein/gelatin mass ratio of 1:1 with 5% PDMS, the composite film showed 128% higher tensile strength, 167% greater elongation. Its moisture barrier properties were improved, showing 88.82° water contact angle and reduced water vapor permeability (2.68 × 10^-10 g·m^-2·s^-1·Pa^-1). These enhancements arise from a uniform and dense microstructure visualized via scanning electron microscopy and strong intermolecular hydrogen bonding interactions revealed by molecular dynamics simulation. Moreover, the composite film delayed visible spoilage by over three days while maintaining 17% higher total phenolics. It also reduced flaxseed oil oxidation, decreasing peroxide and anisidine values to 66.8% and 75.5% of the unpackaged control samples after 28 days. These findings demonstrate that this composite film possesses high potential as a bio-based food packaging material.