Refrigerated storage-induced quality deterioration of Mandarin fish (Siniperca chuatsi): Analyzing the role of endogenous enzymes through TMT-based quantitative proteomics

Tandem Mass Tag (TMT)-based proteomics was employed to elucidate the pivotal role of endogenous enzymes in the quality deterioration of Mandarin fish (Siniperca chuatsi) during refrigerated storage. Proclean 300 was used to inhibit the growth of psychrophilic microorganisms, emphasizing the contribution of endogenous enzymes. Quality characteristics, including pH, water-holding capacity, color, texture, and myofibrillar fragmentation index (MFI), were compared between the Proclean 300-treated group (P-group) and the control group (C-group). Correlation analysis underscored the collaborative role of calpain and cathepsin B in postmortem degradation. Pearson correlation analysis showed that texture characteristics were significantly negatively correlated with MFI and significantly positively correlated with whiteness and L* in the P-group. Differentially expressed proteins (DEPs) analysis identified 66 DEPs, with 40 exhibiting low abundance, including cytoskeleton proteins and hemoglobin subunits, and 26 showing high abundance, primarily metabolic enzymes. Bioinformatics analysis revealed significant enrichment of DEPs within the glycolysis/gluconeogenesis pathway. Furthermore, proteinprotein interaction analysis highlighted key proteins linked to the quality deterioration of Mandarin fish, including beta-enolase, phosphoglycerate kinase 1, and triosephosphate isomerase B. These findings offer valuable insights into the mechanisms behind the quality deterioration of refrigerated Mandarin fish and the intricate relationship with endogenous enzymes.