Identification of taste active compounds in mackerel sauce prepared by enzymolysis-fermentation

Abstract Mackerel sauce was prepared by enzymolysis-fermentation method using mackerel as raw material. Then, the key umami-related compounds were identified, and the umami peptides were separated by column chromatography. A total of 17 free amino acids, 5 organic acids, and 3 nucleotides were detected in mackerel sauce, and the equivalent umami concentration was 6.90 g MSG/100 g. The taste recombinant of mackerel sauce was based on sensory evaluation, and 12 compounds, including Glu, Ala, Val, Ile, His, Pro, citric acid, malic acid, succinic acid, lactic acid, inosine 5′-monophosphate (IMP), and guanosine 5′-monophosphate (GMP), were identified as key umami-related compounds by omission test and addition test. Except for His and citric acid, the concentrations of these compounds were positively correlated with the umami of mackerel sauce, especially IMP and GMP. The peptides in mackerel sauce were separated by two-step column chromatography with DA201-C resin and cellulose DE-52, and the F1 fraction with good umami intensity was important for the umami enhancement of mackerel sauce. LC–MS/MS analysis showed that F1 mainly consisted of peptides, such as EEQCSSS, TSPGPAANY, and STPGNFTGP. This study provided some theoretical basis for the high-quality utilisation of low-value fish and the development of flavour enhancers.