Optimizing rinsing treatments to enhance frozen surimi gel stability by reducing pro-oxidative factors and preserving protein integrity

• Pro-oxidants reduced surimi freeze-thaw stability via actomyosin oxidation. • SBS SCS rinsing (0.4% NaHCO₃ + 0.1% NaCl) improved surimi gel quality. • SBS SCS removed 75.8% lipids and 37.4% myoglobin, reducing gel strength loss. • Pro-oxidants levels correlated with gel deterioration, confirming oxidation’s role. Maintaining gel stability in surimi during frozen storage is crucial for product quality but remains challenging due to protein degradation and lipid oxidation. This study investigated the effects of different rinsing treatments on the gel properties of surimi and explored the underlying mechanisms related to protein structure and residual pro-oxidative factors. The results demonstrated that the SBS SCS rinsing treatment (0.4% NaHCO₃ + 0.1% NaCl) enhanced the freeze-thaw stability of surimi gels, as evidenced by improved gel strength, springiness and whiteness. Notably, after 30-day frozen storage, the surimi treated with SBS SCS demonstrated only a 27.2% reduction in gel strength, which was the lowest among all the rinsed groups. Such performance of the SBS SCS treatments was attributed to the effective removal of 75.8% of lipids and 37.4% of myoglobin (Mb), which helped maintain actomyosin structure under oxidative stress. This was further supported by reduced carbonyl content (19.1%) and surface hydrophobicity (32.3%), along with increased total sulfhydryl content (14.2%), Ca²⁺-ATPase activity (30.7%), and protein solubility (60.2%). Correlation analysis confirmed that carbonyl content was positively associated with lipids, malondialdehyde (MDA), Mb, met-Mb and heme iron, while negatively correlated with gel strength, springiness, and whiteness, indicating that oxidation mediated by these pro-oxidative factors compromises surimi quality. These findings provide scientific support for optimizing rinsing treatments and developing high-quality surimi products.