| Sauce slag is the solid residual after soysauce fermentation. Because sauce slag also contains rich protein and carbohydrates, so it has an important reuse value. At present the main treatment of sauce slag was sold as fodder or fertilizer at low price. So there is great prospect in developing a new way for reusing sauce slag. This paper mainly studied the feasibility of application of sauce slag to soy sauce fermentation. In this paper, the conditions of protease enzymolysis sauce slag were optimized, and then the koji-making and fermentation by compounding enzymolysis sauce slag with the raw materials were investigated, finally a new way of reusing sauce slag was established.Firstly the degree of protein hydrolyisis (DH) of sauce slag were studied by using the acid protease, neutral protease and alkali protease in this paper. By single factor and the response surface experiments, the results showed that when the acid protease (A) under the condition of pH3.10, temperature49.76℃, the ratio of material to water1:2.77, enzyme added amount300U/g, enzymatic hydrolysis time4h, the DH reached to5.59%. When neutral protease (B) under the condition of enzymatic hydrolysis time2.61h, enzyme added amount319.64U/g, the ratio of material to water1:2.73, the DH reached to4.11%. When alkali protease (C) under the condition of pH10.03, the temperature47.20℃, the ratio of material to water1:3.39, enzyme added amount200U/g, enzymatic hydrolysis time3h, the DH reached to4.45%. With the DH as index, investigating the effect of complex protease hydrolyze sauce slag, the results showed that A+B+C composite processing> A+C composite processing> A+B complex processing> B+C composite processing> Single enzyme treatment.On the basis of the above results, this paper also inspected the influence of the addition of sauce slag to koji-making. With protease vigor and the degree of protein hydrolysis as the standard, researching the koji-making effect under the conditions such as addition amount of enzymolysis sauce slag, koji-making temperature and koji-making time. The results showed that under the conditions of the adding20%of enzymolysis sauce slag, koji-making time42h and koji-making temperature32℃, the effect of koji-made was better.Under this koji-making conditions, compared the influence of adding enzyme solution sauce slag by different way hydrolyze sauce slag, with the DH as the index, the order was as follows:A+B+C>A+C>A+B> controls1(no add sauce slag)≥B+C> A> C> B> control group2(add20%sauce slag without enzymosis). The DH of A+C treatment group was similar to A+B+C treatment group. And the experimental results showed that adding composite enzyme solution of sauce slag into koji-making procession, the DH was higher than control group1. The three groups of single enzymes hydrolyze sauce slag, the protease vigor and the DH were lower than the control group I, higher than those in the control group2.Then inspected the influence of adding enzyme solution sauce slag by different way hydrolyze sauce slag on no salt fermenting soy sauce. The total nitrogen utilization rate of control group1and control group2were57.74%and46.51%. The value of the total nitrogen utilization ratio of A+B+C and A+C were59.98%and59.51%, greater than the control group1. The total nitrogen utilization of A+B and B+C were54.27%and53.87%, lower than the control1. The total nitrogen utilization of the four experimental groups were higher than the control group2. Comparing the ammonia nitrogen content of each group’s crude oil, the order was as follows:A+B+C>A+C>control group1>A+B>B+C>control group2. Among them, the ammonia nitrogen content of A+C treatment group is similar to A+B+C treatment group. Analysed other indexes, such as the total acid content, color rate and red index of crude oil, A+B+C and A+C were slightly higher than the control1, and the difference between the two groups were not big.The total acid content, color rate and red index of all the treatment group were higher than control group2. pH value was negatively correlated to total acid.Inspected the influence of adding enzyme solution sauce slag by different way hydrolyze sauce slag on low-salt solid-state fermenting soy sauce. The experimental results showed that the ammonia nitrogen, total acid content, color rate and red index of all the treatment groups showed increasing trend during the fermentation process. pH was negatively correlated with total acid. After finishing fermentation, the total nitrogen utilization rate of the control group1and2were68.81%and57.47%. The total nitrogen utilization ratio of A+B+C and A+C were71.71%and70.11%, greater than the control group1. The total nitrogen utilization of A+B and B+C were66.0%and67.93%, lower than control1. The total nitrogen utilization of all the four experimental groups were higher than the control group2. From flavor composition analysis result, the species of flavor substances, content and characteristic flavor substances species, content of A+C and A+B+C were higher than other two group and control group2. but lower than those of the control group1. Which means A+C and A+B+C group flavor were good, but slightly inferior to the control group1.Comparing the ammonia nitrogen content of each group’s crude oil. the order was as follows:A+B+C>A+C>control group1>A+B>B+C>control group2. Among them the ammonia nitrogen content of A+C treatment group is similar to A+B+C treatment group.Summarized the analysis results of all above experiments as protease hydrolyzing sauce slag, adding enzymolysis sauce slag to koji-making and fermentation, coupled with the actual operation of the factory feasibility and convenience, final selected A+C composite of the enzyme solution sauce slag. Then investigated the cost of it, the results showed that using the enzyme solution sauce slag could reduce every tons raw material cost280yuan. It could also improve the output of soy sauce. The flavor of the product was similar to all raw materials fermenting soy sauce. Therefore, using enzymolysis sauce slag partly replace raw materials in soy sauce fermentation was feasible. |
PDF Full Text Request