Effects of chopping temperature on the gel quality of silver carp (Hypophthalmichthys molitrix) surimi: insight from gel‐based proteomics

Abstract BACKGROUND Morden advanced analytical tools offer valuable information into the understanding of molecular mechanism of traditional food processing. Chopping temperature is well‐known to affect the surimi gel quality of silver carp, but the detailed molecular mechanism is not very clear. In this study, a gel‐based proteomics was performed on the extracted surimi proteins under different chopping temperatures (0, 5, 10, and 25 °C) along with other physicochemical characterization of surimi proteins and gels. RESULTS With increased chopping temperature, protein extractability (in 3% sodium chloride) generally decreased, while the extracted protein generally exhibited larger surface hydrophobicity, reduced intrinsic fluorescence intensity, lower sulfhydryl content. Sodium dodecyl sulfate‐polyacrylamide gel electrophoresis (SDS‐PAGE) profile of extracted protein showed a clear difference at 25 °C when compared with the other three temperatures, and more protein fragmentation occurred. Proteomic analysis of selected bands indicated that major myofibrillar proteins react differently with chopping temperatures, especially at 25 °C. The selected bands contained a variety of other proteins or their fragments, including adenosine triphosphate (ATP) synthase, glyceraldehyde‐3‐phosphate dehydrogenase, glucose‐6‐phosphate isomerase, heat shock protein, parvalbumin, collagen, and so forth. For the surimi gel, water‐holding capacity and gel strength generally decreased with increased chopping temperature. CONCLUSION Our results suggested that chopping at 0–10 °C is acceptable for the production of silver carp surimi in terms of gel strength and water‐holding capacity. However, a chopping temperature near 0 °C led to less protein oxidation and denaturation. The inferior gel quality at 25 °C is linked to a decreased concentration of extracted protein and degradation of major myofibrillar protein, the latter is likely crosslinked with sarcoplasmic proteins. © 2024 Society of Chemical Industry.