Integrated volatolomics and metabolomics analysis reveals the characteristic flavor formation in Chouguiyu, a traditional fermented mandarin fish of China.

[Display omitted] • Comprehensive analysis of flavor formation of mandarin fish from smell and taste. • Nineteen key aroma compounds were identified in fermented mandarin fish. • The differential metabolites presented a significant correlation to the key volatiles. • 5′-nucleotides were reduced, whereas Asp and Glu were increased. • Tryptophan metabolism was the potential generation pathway of the fish stinky. Volatolomics and metabolomics were performed to explore the generation mechanism of the characteristic flavor of mandarin fish during fermentation. This study revealed a novel finding that umami-tasting amino acids, succinic acid, and peptides increased, while taste-presenting nucleotides decreased after fermentation. The results showed that 19 key aroma compounds were identified. The most nitrogenous compounds were produced after fermentation, the total concentration of which was >5 mg/kg. A high odor activity value of 443 was established for stinky indole. PLS-DA showed that sn -glycero-3-phosphocholine, hypoxanthine, creatine, and trimethylamine N -oxide were the key metabolites associated with the key volatiles. Umami-tasting amino acids could contribute to the characteristic taste. Metabolic pathway analysis revealed that tryptophan metabolism, trimethylamine metabolism, and monoterpenoid biosynthesis were the potential generation pathways of indole, trimethylamine, and terpenoids, respectively. Collectively, the results provide thoughts for targeted controlling the flavor of fermented mandarin fish. [ABSTRACT FROM AUTHOR]