Quality analysis and brewing technology of soy sauce by High-salt liquid-state fermentation

The paper adopted Aspergillus oryzae A3-2、A18-3 obtained after mutation screening in our lab as the main fermentation strains,the koji-making temperature(prophase 31 ℃,middle 30 ℃,late 29 ℃) and the fermentation temperature(prophase 15 ℃,middle 25 ℃,late 30 ℃) to carry out a brewing experiment.Results showed: the quality of soy sauce by high-salt liquid-state fermentation was improved,and ammoniacal nitrogen of soy sauce was obviously increased;in particular,free amino acids of soy sauce with fermentation period four months and six months was respectively 6.622 g/dL and 7.782 g/dL,and the essential amino acids were about 40 percent of the total free amino acid.The conclusion was drew that Aspergillus oryzae A3-2,A18-3 were preferred for brewing technology of soy sauce by high-salt liquid-state fermentation,and also compounding strains and fine regulation not only improved the quality of soy sauce but shortened the fermentation period.