Elucidating the Changes in Metabolites and Physicochemical Quality of Greater Amberjack (Seriola dumerili) During Wet Aging

Wet aging is a promising strategy for improving the eating quality of high-value aquatic products, yet the metabolic basis underlying quality and flavor changes in greater amberjack (Seriola dumerili) remains unclear. In this study, greater amberjack was wet-aged under refrigerated conditions, and changes in physicochemical properties, taste attributes, free amino acids (FAAs), and metabolite profiles were evaluated. The pH values initially decreased and then increased, whereas moisture content declined during the aging period. Total viable counts (TVC) increased with aging time but remained below the total microbial limit for raw aquatic products. TCA-soluble peptides increased, while UFAAs increased and BFAAs and TFAAs decreased (p < 0.05). TBARS values also increased, indicating enhanced lipid oxidation. Electronic tongue analysis showed increased sensor responses associated with umami and saltiness after aging. Metabolomic analysis showed differences among aging stages, with glycerophospholipid metabolism, sphingolipid metabolism, and alanine, aspartate and glutamate metabolism significantly affected. During wet aging, L-glutamic acid, taste-related peptides, lipid oxidation products, and phospholipid degradation products accumulated, a pattern consistent with proteolysis and lipid remodeling. Overall, wet aging altered the instrumental taste profile and promoted the accumulation of taste-related compounds and lipid-derived metabolites that may serve as potential precursors for volatile formation in greater amberjack. These results provide the basis for optimizing wet aging for aquatic products.