Investigation of the synthesis of biogenic amines and quality during high-salt liquid-state soy sauce fermentation

Soy sauce is a traditional fermented food in Asia. In this study, we determined the contents of biogenic amines (BAs) in commercial high-salt liquid-state fermented (HLF) soy sauce. Using high performance liquid chromatography (HPLC), we evaluated the effects of salinity on the synthesis of BAs during soy sauce fermentation. According to the results, various grades of HLF soy sauce demonstrated significant differences (p < 0.05) in the contents of BAs. The major BAs in laboratory-made soy sauce include spermidine (SPD), histamine (HIS), and tyramine (TYR). After fermentation, the contents of SPD, HIS, and TYR in the 20% salinity group were significantly (p < 0.05) reduced than those in the 16% and 18% salinity groups, suggesting that the salinity might be a crucial factor for reducing the biogenic amines during HLF soy sauce fermentation. We also found a positive correlation between the contents of amino nitrogen and biogenic amines.