Comparison of non-volatile taste-active components in fish sauce produced from lizardfish Saurida wanieso viscera under different conditions

Lizardfish is a major ingredient for the manufacture of surimi in Japan, and its viscera are considered a novel source of protease to enhance protein autolysis. We investigated the non-volatile taste components of fish sauce produced from the lizardfish Saurida wanieso viscera in order to clarify the effects of fermentation conditions on the quality of fish sauce. Samples were fermented for 40 days under three sets of conditions: group 1, pH 7.0 and 60 A degrees C; group 2, pH 11.0 and 40 A degrees C; and group 3, uncontrolled pH and ambient temperature. Group 2 showed the highest concentration of umami amino acids (1,195.29 mg/100 ml) and sweet amino acids (2,033.60 mg/100 ml). High levels of lactic acid (1,219.65 mg/100 ml), acetic acid (367.08 mg/100 ml), and pyroglutamic acid (261.66 mg/100 ml) were also found in group 2. In addition, investigation of nucleic acid-related compounds revealed differences in the degree of nucleotide hydrolysis among the three groups during fermentation. Sensory evaluation showed that group 2 had the highest umami and the lowest bitterness, indicating that this group had the most preferable taste. These results reveal that fermentation under conditions optimal for endogenous proteases is beneficial for producing a product with optimal taste qualities.