Influence of reheating methods on the quality, protein oxidation, and aggregation of sturgeon–silver carp composite myofibrillar protein gel

Abstract BACKGROUND Reheating methods critically decide the final eating quality of frozen surimi products. This study systematically investigated the effects of six common reheating methods, namely steaming (STM), microwaving (MW), low‐temperature air frying (LTAF), low‐temperature roasting (LTR), high‐temperature air frying (HTAF), and high‐temperature roasting (HTR), on the quality deterioration mechanisms of sturgeon–silver carp composite myofibrillar protein gel. RESULTS Results demonstrated that the choice of reheating method directly governed the extent of quality loss. Severe dry‐heat methods, particularly HTAF, induced the most significant deterioration, characterized by pronounced surface wrinkling, excessive moisture loss (moisture content of STM was 22.30% higher than that of HTAF), and aberrant textural hardening. Molecular analysis revealed that these methods provoked intense protein oxidation, evidenced by a drastic depletion of sulfhydryl groups and a marked increase in carbonyl content (11.5 ± 0.86 versus 31.50 ± 0.92 nmol mg −1 , P < 0.05, fresh group versus HTAF). Consequently, oxidation triggered severe myosin heavy chain (MHC) degradation and aggregation, with HTAF showing the lowest MHC relative content (9.79 ± 0.24%). Fourier transform infrared spectroscopy analysis revealed a pronounced shift in protein secondary structure from ordered ( α ‐helix, β ‐turn) to disordered ( β ‐sheet, random coil), with HTAF exhibiting the most substantial accumulation of disordered structures ( P < 0.05). Fluorescence spectroscopy further confirmed tertiary structure unfolding, as evidenced by a redshift in the maximum emission wavelength, indicating the exposure of tryptophan residues to a more polar environment. Ultimately, these changes led to extensive protein aggregation, reflected in reduced solubility and increased particle size. In contrast, milder methods (STM, MW) effectively mitigated these detrimental changes. CONCLUSION These findings establish a mechanistic pathway linking heating conditions to protein oxidation, structural destabilization, and ultimately final product quality. This study provides a scientific basis for selecting appropriate reheating strategies to preserve the quality of surimi‐based convenience foods. © 2026 Society of Chemical Industry.