Synergistic effects of chicken skin collagen and tamarind seed polysaccharide on the cryoprotective properties and quality preservation of hairtail (Trichiurus lepturus) surimi.

Abstract

In this study, the synergistic cryoprotective efficacy of chicken skin collagen (CSC) and tamarind seed polysaccharide (TSP) was evaluated using hairtail surimi subjected to five freeze-thaw (F-T) cycles. It was revealed that 0.5% CSC and 0.5% TSP (CSC-TSP) composite significantly outperformed individual components and surpassed commercial sucrose-sorbitol cryoprotectants (PC). Specifically, the CSC-TSP complex effectively restricted water migration, which significantly reduced thawing and cooking losses (p < 0.05). Simultaneously, the complex maintained the highest water-holding capacity (WHC), which was 1.70-fold that of the BC group. Low-field nuclear magnetic resonance (LF-NMR) and magnetic resonance imaging (MRI) confirmed that CSC-TSP effectively constrained water mobility by increasing the proportion of immobilised water. Furthermore, the CSC-TSP complex significantly inhibited the loss of whiteness and the accumulation of yellow pigments in hairtail surimi gel. At the molecular level, it reinforced intermolecular interactions, fostering an elastic gel network that preserved texture properties. Notably, the CSC-TSP complex mitigated myofibrillar protein (MP) oxidation, maintained Ca2+-ATPase activity, and prevented α-helix-to-disorder transitions, thereby promoting a dense, uniform three-dimensional network with fine pores and smooth surfaces. Quantitatively, image fitting of the microstructural pore size distribution demonstrated that the CSC-TSP complex constricted the MP voids, tightly concentrating the pore diameters in the range of 10-20 μm while suppressing the formation of larger pores (40-100 μm). Correlation analysis further highlighted that preserving MP structural integrity and restricting water migration were pivotal for quality retention. Overall, the CSC-TSP complex represents a highly efficient cryoprotectant with substantial application potential in frozen aquatic product processing.