Dynamic changes in flavor characteristics of marinated silver carp during marinating: Insight from amino acid...

Marinated silver carp is highly favored for its distinctive flavor profile, but the role of amino acid metabolism in the formation of characteristic flavors during marinating remains unclear. This study systematically investigated the formation and evolution mechanism of flavor during the marinating of silver carp through physicochemical analysis, microstructural characterization, flavor substance identification and metabolomic analysis. The marinating process promoted moisture migration and myofibril coarsening, leading to a progressive yellowing of color and a decline in hardness and chewiness of the marinated silver carp as cooking time increased. Although the total FAA content continued to decrease, the EAA/TAA ratio at both 90 min and 120 min met the ideal protein pattern recommended by FAO/WHO. Additionally, the non-targeted metabolome identified 1591 differential metabolites, of which 54 were significantly associated with amino acid metabolism. KEGG pathway analysis showed that the amino acid metabolic pathway (such as histidine metabolism, phenylalanine metabolism, and lysine biosynthesis) was dominant and its dynamic changes reflected the stage-specific characteristics of protein degradation. The 47 key compounds (VIP>1) identified by GC-MS showed significant positive correlation (r > 0.7, P < 0.05) with most organic acids and significant negative correlation (r < -0.7, P < 0.05) with most amino acids and their derivatives, highlighting the critical role of amino acid metabolism in flavor formation during the marinating of silver carp. These findings provide a scientific basis for the targeted modulation of flavor in marinated silver carp, offering insights for optimizing processing parameters to enhance sensory quality.