Effect Of Wheat Bran Enzymolysis Liquid On The Quality Of Low-salt Solid-state Fermented Soy Sauce

Soy sauce also named of bean oil, is originated in China, and evolved by sauce. The soy sauce is using soy bean(bean pulp) as protein material and wheat bran as starch-containing feedstocks through pretreatment of raw material, inoculate, koji-make, fermentation and so on. In this work, analysis the component of wheat bran, make enzymatic hydrolysis solution of wheat bran, and addition this hydrolysis solution into the koji of low-salt solid-state replace the water of traditional fermented. Analysis the physical-chemical indexes, main flavor substance and the color of the soy sauce adopt HS-SPME-GC, and discuss the impact on soy sauce. The main results were as follows:1. The main components of wheat bran is:water8.19%, protein16.17%, starch8.83%, fat1.85%, dietary fiber47.31%and pentosan18.48%. And water-soluble pentosans(WSP) accounts for37%, water-insoluble pentosans(WIP) accounts for63%approximately. The monosaccharide composition of pentosans mainly were arabinose, xylose, mannose, glucose and rhamnose.2. To enzymolysis wheat bran using neutral protease, neutral protease and xylanase, respectively. And determine the optimum conditions of the enzymes. The result is, the optimum condition of the neutral protease was:enzyme dosage is1.77%, enzymolysis temperature is55.96℃, enzymolysis time is3.00h, pH is7.30; the optimum conditions of stable amylase was:enzyme dosage is1.75%, enzymolysis temperature is65.16℃, enzymolysis time is3.41h, pH is6.00; taking the content of xylose of enzymatic hydrolysis as criterion, determined the optimum conditions of neutral protease was:enzyme dosage is1.50%, enzymolysis temperature is48℃, enzymolysis time is80min, pH is6.00; taking the content of ferulic acid of enzymatic hydrolysis as criterion, determined the optimum conditions of neutral protease was:enzyme dosage is2.00%, enzymolysis temperature is58℃, enzymolysis time is2h, pH is4.00.3. After the koji which added with the enzymatic hydrolysis of the wheat bran fermented30days, the amino nitrogen, total nitrogen and salt-free soil solution mass all higher than control group. The protease treatment group is the highest for the amino nitrogen and total nitrogen. The content of the amino nitrogen and total nitrogen of protease treatment group increased33.68%and20.98%than control group.For the salt-free soil solution mass, the protease-amylase treatment group is the highest, and the content increased7.21%than control group. The content of4-EG and HEMF of treatment group also increased obviously through the HS-SPME-GC analysis. The content of4-EG and HEMF of the xylanase-cellulase treatment group and amylase treatment group is3.3and3.2times of the control group,respectively; the protease-amylase group and xylanase group is2.5and2.4times of the control group, respectively; and the amylase group and the control blank group is increased47.40%and43.93%to control group, respectively. To HEMF, the content range from high to low is:xylanase group> protease-amylase group> protease group> xylanase-cellulase group> amylase group. In a sense, the color of the amylase treatment group is reddish brown, glossy and fragrance is rich. So, the amylase enzymatic hydrolysis can improve the flavor and color of the low-salt solid-state fermented soy sauce significantly.