Investigating the Shelf-Life Extension of Shrimp Surimi Using a Polysaccharide-Based Film from Alpinia oxyphylla

To investigate the effect of a polysaccharide-based composite film (ASC) composed of <i>Alpinia oxyphylla</i> polysaccharide (its molecular weight was approximately 4.07 kDa, and the monosaccharide composition was predominantly glucose and galacturonic acid), sodium alginate, and calcium chloride on the storage quality of shrimp surimi, this study compared the preservation efficacy of the ASC film with that of treatments using chitosan, potassium sorbate, ascorbic acid, sodium alginate, <i>Alpinia oxyphylla</i> polysaccharide, and distilled water. Samples were stored at 4 °C for 12 days, and evaluations were conducted by measuring film structural characteristics and quality indicators of shrimp surimi. Results showed that the ASC groups (where <i>Alpinia oxyphylla</i> polysaccharide was added at 20%, 30%, and 40% of the sodium alginate mass, designated as ASC 20%, ASC 30%, and ASC 40%) significantly outperformed the control group across all quality indicators. The ASC 30% group demonstrated the best overall preservation performance, effectively delaying oxidative browning, protein degradation, lipid oxidation, and microbial growth in shrimp surimi. The ASC 40% group exhibited particularly strong antibacterial effects, while the ASC 20% group also showed stable preservation performance. The composite film combines the antioxidant and antibacterial activities of <i>Alpinia oxyphylla</i> polysaccharide with the barrier and moisture-retention properties of sodium alginate, forming a stable three-dimensional network structure through calcium chloride cross-linking. It is superior to single/individual chemical preservatives in terms of film-forming ability, functionality, and safety, providing a natural, effective, and environmentally friendly preservation approach for shrimp surimi and other aquatic products. It also offers a theoretical foundation and practical reference for the development of natural preservation technologies in the food industry.