Carboxymethyl chitosan–gelatin edible films incorporating fava bean antimicrobial peptides for active food preservation

This study developed a sustainable, edible composite film based on carboxymethyl chitosan (CMCS) and gelatin (GL), incorporating antimicrobial peptides from fava beans (FBAP) for active food packaging. The antimicrobial composite film (U-CMCS/GL-FBAP) was prepared via ultrasonication-assisted cross-linking. Structural analysis confirmed enhanced hydrogen-bonding interactions among the components. The film exhibited a water contact angle of 108.3°, indicating modulated surface wettability. The incorporation of FBAP markedly improved the mechanical properties, increasing the tensile strength and flexibility by approximately 2 times and 1.12 times, respectively. The film also demonstrated a low water vapor permeability (WVP) of 3.55× 10 −11  g·m/(m 2 ·s·Pa) and significant antioxidant activity, with a DPPH and ABTS radical scavenging rates of 40.89% and 79.44%. Furthermore, the film demonstrated strong UV-blocking properties and sustained antibacterial activity, achieving a cumulative FBAP release of 65.82% over 96 h. In application trials on winter jujubes and cherry tomatoes, the coating effectively extended the shelf life by 11 days, respectively, primarily by suppressing microbial growth and reducing quality deterioration. Overall, the U-CMCS/GL-FBAP film combines balanced surface properties, enhanced mechanical and barrier performance, antioxidant capacity, and controlled antimicrobial release, offering a promising and sustainable strategy for the high-value utilization of legume by-products in food preservation.