Comparative study on the in vitro digestive characteristics of surimi gels cross-linked by EGCG and/or TGase

This study examined the synergistic cross-linking effect of epigallocatechin gallate (EGCG) and transglutaminase (TGase) on the digestion characteristics of surimi gels via the INFOGEST in vitro digestion model. The digestibilities of the control, EGCG, TGase, and EGCG/TGase groups were 83.83, 82.54, 79.16, and 77.33%, respectively. The average particle size decreased from over 1000 μm in the oral phase to below 100 μm in the intestinal phase, and most proteins were degraded into peptides smaller than 15 kDa. The essential amino acid ratios (EAA/TAA ∼37.7, EAA/NEAA ∼60.5%) remained stable among all groups. EGCG/TGase synergistic cross-linking enhances texture, stabilizes digestibility, and enriches peptide diversity, showing great potential in the production of high-nutrition functional surimi products.