Non-muscle proteins alleviate 118 °C sterilization-induced gel quality deterioration by non-covalently modulating myofibrillar protein conformation and aggregation.

The improvement effects of non-muscle proteins (soy protein isolate (SPI), egg white protein (EWP) and whey protein concentrate (WPC)) on the quality deterioration of high-temperature (118 °C) sterilized surimi gels were systematically compared. Supplementation with 4% SPI, 4% EWP, or 8% WPC effectively alleviated the heat-induced quality deterioration of gels, among which 4% SPI exhibiting the best improvement effect, increasing gel strength by 49.15% and water holding capacity by 7.6% compared with the control group. Multi-spectral analysis showed SPI improved myofibrillar protein (MP) solubility, promoted protein unfolding, and strengthened molecular cross-linking. Rheology indicated increased storage modulus (G'), while microstructural images confirmed denser gel network. SPI also inhibited excessive aggregation of MP at 118 °C. Molecular docking and dynamics simulations confirmed stable MP-SPI complexes through non-covalent interactions. These findings demonstrate innovative application of SPI in sterilized surimi gels, providing new insights for the development of ready-to-eat surimi products.