Screening Of Strain And Optimization Of Fermentation Technology For Production Of Soy Sauce

UV treated a strain of Aspergillus oryzae traditionally used for production of soy sauce in a famous company located in Guangdong and a mutant with high-activity neutral proteinase was obtained, named YB-1. The amino-nitrogen content and the organoleptic properties of soy sauce were improved by optimization of fermentation technology.The Aspergillus oryzae was induced under different strength of ultraviolet radiation and neutral proteinase activity was used as an index for screening the strains using for fermentation of soy sauce. The results showed that a mutant called YB-1 had neutral proteinase activity 54% higher than that of the starting strain, and the activity of cellulase and pectase also increased significantly. It proved that this mutant strain has potential application in high-salt, liquid fermentation for production of soy sauce.The study optimized the fermentation technology for production of soy sauce. The results showed that part of wheat floor replaced by peanut cake or sesame cake increased the amino-nitrogen and total nitrogen content of soy sauce possibly due to their high content of protein. Furthermore, addition of peanut cake or sesame cake significantly improved the organoleptic properties of soy sauce, including the appearance and the taste.