Effects Of The Interaction Of Yeast And Lactic Acid Bacteria On The Flavor Of Soy Sauce

Soy sauce had become an indispensable fermentation condiment for Chinese people.People pay attention to and study its nutritional flavor.Yeast and lactic acid bacteria can regulate the nutritional flavor of soy sauce.The research on the effect of adding yeast on soy sauce had been mature,but the research on the interaction of multi-bacteria is still immature.The results of dialysis culture of lactic acid bacteria,S and T in soy sauce were compared with those of S and T in soy sauce.The change trend of lactic acid bacteria was studied and the index of soy sauce was determined.The experimental group with more kinds of flavor substances was selected to verify the fermentation of soy sauce and determined the flavor substance components of soy sauce mash.Seed koji had a great influence on the later fermentation of soy sauce,which directly affects the final quality of soy sauce.The results showed that the spore number of koji reached 1.8×1010/g at 72 hours,and the optimum time for koji harvesting was determined.The activity of neutral protease,acidic protease and cellulase in Aspergillus oryzae 3.042 reached the maximum at 36 hours,2129.375(U/g),1156.3(U/g)and 1131.92(U/g),respectively.The activity of glucoamylase reached the maximum at 42 hours,and the maximum activity of glucoamylase was 1493.49(U/g),but there was no significant difference from that of 1339.42(U/g)at 36 hours.The results of sauce dialysis culture showed that lactic acid bacteria could promote yeast in the early stage.Although the percentage of alcoholic flavoring substances added with Lactobacillus group was lower than that without Lactobacillus group,there was no decrease in the types of alcoholic flavoring substances,and the types of ester flavoring substances were obviously enriched,and the total types of flavoring substances were also increased.According to the kinds of flavor substances in sauce mash,four groups with more flavor were selected as the experimental group with lactic acid bacteria added.The content of ethanol,isoamyl alcohol,phenylethanol,phenylacetic acid,isovaleraldehyde,3-methylthiopropionaldehyde,benzaldehyde,benzaldehyde,2-ethyl-6-methylpyrazine and guaiacol in soy sauce was increased by adding lactic acid bacteria on the fifteenth day,adding S yeast on the thirtieth day and adding T yeast on the forty-fifth day,and the sensory evaluation scores of taste and smell were the highest.The results showed that lactic acid bacteria and two kinds of yeasts could increase the characteristic flavor substances content of soy sauce,and the final flavor substances of this group were 102 kinds.The optimum combination of adding lactic acid bacteria on the fifteenth day,adding S yeast on the thirtieth day and adding T yeast on the forty-fifth day was determined.