Preparation of gelatin/gelatin-dextran/gelatin-based three-layer films with cinnamaldehyde and α-tocopherol for scallop (Patinopecten yessoensis) adductor muscle preservation

In this study, three-layer films based on gelatin/gelatin-dextran/gelatin with different concentrations of functional fillers (cinnamaldehyde and α-tocopherol) were fabricated by using the layer-by-layer casting method to preserve refrigerated scallop adductor muscle. The films demonstrated excellent bonding, with functional fillers creating a porous cross-section, a slightly rough surface, and increased hydrophobicity while maintaining thermal stability. The crystallinity, water contact angle, thickness, opacity, antioxidant activity, and antibacterial activity of the films were increased, while the water vapor permeability and mechanical properties were decreased with increasing concentrations of the functional fillers. The film with 1.2% active fillers showed over 82% free radical scavenging activity and significant inhibition zones (24.7 ± 1.2 to 43.9 ± 1.8 mm) against five foodborne pathogens and spoilage bacteria. Both cinnamaldehyde and α-tocopherol demonstrated controlled release properties in four food simulants, with the maximum release and minimum release times observed in 95% ethanol (9.0 h) and distilled water (2.0 h), respectively. Overall, the introduction of 1.2% of active fillers into the films significantly enhanced the chemical and microbiological stability of refrigerated scallops and prolonged their shelf life by 6 days. Furthermore, the developed films showed excellent controlled release, antibacterial, and antioxidant properties, making them potential candidates for preserving seafood.