Application of Gelatin/Chitosan Films Loaded with Seaweed Extract of Ready-to-Eat Sea Cucumbers Preservation During Ambient-Temperature Storage

Achieving ambient temperature storage of ready-to-eat sea cucumber (RTE-SC) remains a critical scientific challenge that urgently needs to be addressed in the industry. Recently, bioactive packaging materials have been increasingly applied in the aquatic product preservation, demonstrating their effectiveness in enhancing storage stability and extending the shelf-life. In this study, Seaweed extract (SE) was employed as a functional and bioactive component to fabricate gelatin/chitosan composite films (G-C–SE), and the preservative efficacy of the prepared films was systematically evaluated on ready-to-eat sea cucumber (RTE-SC) under ambient temperature storage. The SE was prepared and characterized in terms of extraction yield, total phenolic content, and total flavonoid content, all of which confirmed its satisfactory in vitro antioxidant and antimicrobial activities. The experimental results demonstrated that extraction using 60% (v/v) ethanol solvent yielded the most favorable outcomes, exhibiting satisfactory antioxidant and antimicrobial activities. Subsequently, the characterization and other physicochemical properties revealed that the incorporation of SE effectively facilitated the hydrogen-bonding interactions and improved the mechanical strength, barrier performance, and thermal stability of composite film matrix. When applied to the preservation of RTE-SC, the G-C–SE films exhibited remarkable quality-regulating effects. After 5 days storage, compared with the control group (CON), the protection of G3.3:C0.2−0.5% film (containing 3.3 wt% gelatin, 0.2% wt% chitosan, and 0.5 wt% L. japonica extract) resulted in a 26.07% reduction in the TCA-soluble oligopeptides content, a 10.39-fold decrease in glycosaminoglycan release, and an 11.28-fold suppression of TBARS elevation. Additionally, this treatment effectively retarded the rise in TVB-N accumulation, delayed textural deterioration, and maintained superior visual appearance throughout the storage period. These findings demonstrate that the G-C–SE composite film, as an active packaging material, can significantly mitigate the quality degradation of RTE-SC during ambient temperature storage, thereby providing a promising technological strategy for the application of bioactive films in aquatic food preservation.