Physicochemical characteristics and metabolite composition of fish sauce made from large yellow croaker roe enzymatic hydrolysates based on three fermentation temperatures

Large yellow croaker roes were used to make fish sauce using enzymolysis method, and the impact of different fermentation temperatures (25, 32 and 40 °C) on the physicochemical characteristics and metabolite composition was revealed. Results indicated that compared with 25 and 32 °C, the higher contents of total acidity, amino nitrogen, total soluble nitrogen, and the deepening of the nonenzymatic browning degree of fish sauce fermented at 40 °C were obtained. The total volatile basic nitrogen content at 40 °C was lower than 32 °C. The ideal fermentation temperature should be 40 °C. The metabolomics analysis of fish sauce showed that 40 °C significantly increased the abundance of hippuric acid, 3-hydroxy hippuric acid, hydrocinnamic acid and heptanoic acid compared with other temperatures, but decreased trimethylamine N-oxide, 15-methyl palmitic acid, N6-succinyl adenosine and nicotinamide. These results expand the utilization pathways of low-value fish roes, and provide a promising reference for the manufacturing of high-quality fish sauce. [Display omitted] •Large yellow croaker roe enzymatic hydrolysates were used to produce fish sauce.•Chemical properties of fish sauce fermented at 25, 32 and 40 °C were revealed.•Physicochemical characteristics of fish sauce at 40 °C were better than 25 and 32 °C.•The metabolite composition of fish sauce was revealed by metabolomics technique.•Fish sauce fermented at 40 °C produced more flavor compounds than 25 and 32 °C.