The Effect Of Inoculation Fermentation On The Quality Of Dried Beans And The Development Of Dry Powder Starter

Ladou is a traditional Chinese fermented soy product.At present,the fermentation of waxy beans is mostly natural fermentation or single-bacteria fermentation,and most of them are household-type production,and low degree of industrialization.Therefore,this paper is devoted to studying the effect of mixed fermentation on the quality of waxy beans,developing waxy beans with good export flavor and suitable for industrial production,and researching the freeze-drying technology of fermentation strains,and applying freeze-dried powder to fermented wax beans and to study the changes in its quality.In this experiment,Bacillus subtilis,Bacillus amyloliquefacicns and Lactobacillus sake were used as fermentation strains for mixed bacteria design,and the strains were lyophilized and applied to fermented wax beans.The results of this test are as follows:1.In single-fermented waxy beans,inoculating fermentation can reduce the pH and Aw of waxy beans,inhibit the increase of the hardness of waxy beans,making the texture of waxy beans soft and easier to chew.The protease activity and total amino acid content of the fermented waxy beans in the inoculation group were significantly higher than those in the blank group(P<0.05).Among them,the protease activity and total amino acid content of the fermented waxy beans of B.subtilis and B.amyloliquefaciens groups(P<0.05);the amino acid content of fermented waxy beans in B.subtilis group and Bacillus amyloliquefaciens group was higher than that in other groups(P<0.05);by analyzing the volatile content of relative content of 0.1%or more,the alcohol and aldehyde content of the fermented waxy bean of B.subtilis group was significantly higher than other treatment groups(P<0.05).The quality of the fermented waxy beans in the inoculation group was significantly higher than that in the blank group(P<0.05),and the subtilis spores were evaluated by scoring the appearance and taste of the four groups of different treatment groups.B.subtilis and L.sake groups wax beans fermented taste index significantly better than the other treatment groups(P<0.05).2.Using Design-Expert 8.06 software to compound the three strains to be used,the results showed that the pH of the fourth group(B.subtilis:B.amyloliquefaciens:L,sake=0.033:0.367:0.100)fermented wax beans and Aw was significantly lower than other treatment groups(P<0.05);in the contribution of texture,the hardness and chewiness of the fourth group of fermented wax beans were significantly lower than other treatment groups(P<0.05);group 4 The protease activity and amino acid content of fermented wax beans were also significantly higher than those of other treatment groups(P<0.05).The alcohol content and aldehyde content of the fourth group of fermented wax beans were analyzed by analyzing the volatile flavor substances with relative content above 0.1%.The scores of the fourth group of fermented wax beans were significantly higher than those of other treatment groups(P<0.05).Considering the combination,the ratio of the fourth group of composite bacteria was selected as the optimal fonnula for the fermentation strain of the waxy bean.3.On the basis of previous studies,the freeze-drying technology of strains was studied.The optimal centrifugal collection conditions were 6000 g and 10 min.The optimal compounding agent for Bacillus subtilis was skim milk(10%),cysteine(9.49%),trehalose(4.75%),mannitol(3.39%),and lyophilization survival rate up to 85.53%;the best compounding agent for Bacillus amyloliquefaciens is skim milk(10%),trehalose(11.06%),lactose(7.03%),sodium glutamate(3.00%),freeze-drying survival rate up to 85.59%;the best compounding agent for Lactobacillus sake is skim milk(10%),trehalose(10.59%),sucrose(7.06%),mannitol(3.79%),and the lyophilization survival rate can reach 84.67%.4.The lyophilized powder starter was applied to the wax,the pH and Aw of the fermented wax were significantly lower than that of the blank group(P<0.05),and the final pH of the commercial starter and the compound starter was added.5.29 and 5.31;studies have shown that the protease activity and total amino acid content of the fermented waxy bean with the composite fermenting agent added in this study are significantly higher than that of the commercial starter group(P<0.05),and the free amino acid content of the fermented waxy bean in the inoculation group Significantly higher than the blank group(P<0.05),but the difference in amino acid content between the two groups of waxy beans inoculated with commercial starter and compound starter was not significant(P>0.05);the volatile flavors with relative content above 0.1%were analyzed.The content of alcohols and ketones in the commercial starter group was significantly higher than that in the other two groups(P<0.05).The content of aldehydes and esters in the fermentation group of the composite bacteria was significantly higher than that of the other two groups(P<0.05);The scores of the appearance and taste of waxy beans in different treatment groups were significantly better than those in the blank group(P<0.05).At the same time,the self-developed compound freeze-dried powder starter was used in fermented cured beans,and its taste,texture,aroma and other qualities were more acceptable.