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

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: , 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.