Metabolomic insights into formation and dynamic changes of taste in semi-dried Silver Carp (Hypophthalmichthys molitrix) throughout the drying process: key roles of metabolites derived from protein and nucleotide degradation

This study investigated the formation and dynamic changes of taste-active compounds during semi-dried silver carp drying. TCA-soluble peptides and free amino acids significantly increased after 8-16 h at traditional commercial drying temperature of 45 °C. Umami amino acids Glu exhibited the greatest increases from 1.85 mg/100 g (fresh) to 127.38 mg/100 g (48 h-dried). Umami nucleotide adenosine 5'-monophosphate (AMP) significantly increased after 8-16 h, as did bitter nucleotides hypoxanthine riboside (HxR) and hypoxanthine (Hx). Metabolomic analysis showed amino acid and nucleotide metabolism predominated in the first 8 h, contributing to distinctive savory taste. The synergistic balance of key taste-related metabolites, including oligopeptides (umami and bitter), amino acids (umami, sweet, bitter), nucleotides (umami and bitter), and organic acids (sourness and umami), played a key role in taste perception. Sensory evaluation confirmed the 8 h sample exhibited the highest taste acceptance. These findings provide valuable insights for taste regulation in semi-dried fish products.