Analysis of microorganisms and main flavor substance in first stage of soy sauce fermentation

With the traditional processing of soy sauce,and incubated with pure culture of Aspergillus oryzae and Zygosaccharomyces rouxii,the soy sauce was fermented at natural fermentation.The analysis of fungi,yeast and lactic acid bacteria's number had been applied with dilution plate counting methods,and the flavor substance was extracted with anhydrous ether and analyzed by gas chromatogram.Our results showing that the quantity of fungi decreased along fermentation time,the number of yeast and lactic acid bacteria at fermentation beginning is 1.2×103 CFU/g and 7.6×102 CFU/g respectively,from then on,the number of them increased quickly to 2.4×108 CFU/g and 3.2×106 CFU/g at 6 and 7 days,after that point,they decreased gradually but stayed at 103 CFU/g from 15 days.Guaiacol was found in flavor substance,its content in flavor substance was 0.136 5% after 28 days fermentation.