Analysis On The Growth And Production Aroma Components Of Zygosaccharomyces Rouxii During The Fermentation Of The Soy Sauce

This paper focus on the study and optimize the morphology and the growth of Zygosaccharomyces rouxii which is the mainly fermentation yeast used during brewing process of Chinese traditionary brewing soy sauce, analyzed the effect of Zygosaccharomyces rouxii inoculation of the soy sauce on physical and chemical characters in the process of fermentation,and tested the flavor components of the soy sauce during the fermentation period that after added the Zygosaccharomyces rouxii. The main experimental procedures and results are as follows:1. The optimum growth conditions of Zygosaccharomyces rouxiiThe results of the study on the actication of the yeast and its growth conditions indicated that salt concentration is the one of the major factors influencing Zygosaccharomyces rouxii’s growth, and its optimum growth salt concentration is10%.The other major factors affecting the growth of the yeast are temperature, pH Value, and ionic strength in water. The optimum growth temperature is30℃and the optimal growth pH value is4.5, the optimum growth of calcium ion concentration is0.05mol/L. Based on the analysis of the four factors for the orthogonal experiment, the optimal growth conditions for Zygosaccharomyces rouxii salt concentration of10%, the temperature of30℃,the pH value of5,the calcium ion concentration of0.05mol/L.2.The main effect of physical and chemical properties of the soy sauce fermentation system by Zygosaccharomyces rouxiiBased on dynamic monitoring of the protease enzyme activity, amino nitrogen content, ammonia content and total nitrogen content changed in the fermentation backing material of soy sauce inoculating with Zygosaccharomyces rouxii, we found that the impact of the physical and chemical characters to the soy sauce by the yeast is not obvious,In the process of the fermentation, the yeast reduces the protease enzyme activity, prolongs the rising time of the amino nitrogen content, suppresses the ammonia content to a certain extent, and essentially has no significant effect on contribution to improve the total nitrogen content and the protein utilization.3.The analysis of the aroma componentsBy using head space-solid phase microextraction coupled with gas chromat ogragh and mass spectrometry(SPME-GC/MS) to assess the volatile substancesof the experimental group adding the Zygosaccharomyces rouxii, the experi mental group yeast-free and the control group real soy sauce after fermenting50days. The results shows that the experimental group with Zygosaccharomyce s rouxii alone detected19kinds of volatile substances, include2kinds of alco hols,4kinds of esters,1kind of phenols,1kind of aldehydes,2kinds of ketones,8kinds of heterocyclic compounds and1kind of alkanes. The experimental gr oup with mixed fermentation of Zygosaccharomyces rouxii and Aspergillus oryz ae detected23kinds of volatile substances, include2kinds of alcohols,6kinds of esters,3kinds of acids,1kind of phenols,3kinds of ketones,4kinds of he terocyclic compounds and4kinds of alkanes. The experimental group with Zy gosaccharomyces rouxii-free detected only7kinds of volatile substances, includ e3kinds of alcohols,1kind of esters,1kind of phenols and2kinds of alkane s. Compared with the experimental groups, we detected76kinds of volatile su bstances, include12kinds of alcohols,12kinds of acids,9kinds of esters,7ki nds of phenols,1kind of ethers,8kinds of aldehydes,3kinds of ketones,10kin ds of heterocyclic compounds and other14kinds of nonaromatic volatile subst ances.