Fermented Wheat Gluten Preparation And Its Application

The wheat gluten enzymatic hydrolysate which is rich in glutamine peptides has the same physiological function with the glutamine, it plays an important role in the maintenance of the structure and function of the intestinal tract. Nevertheless, the hydrolysis process exists several problems, such as the low substrate concentration, the less enzyme working sites and the high price of the enzymes. These shortcomings finally result in the low efficiency of the enzymatic procedure and the high cost of the production process, which bring certain obstacles for large-scale production. In this study, the production process of fermented wheat gluten which is rich in glutamine peptides was studied and the fermentation product’ physiological effects were evaluated.The strains with potential high protease activity were selected from Mold, Yeast, Lactobacillus, Bacillus and five unknown strains obtained from wheat gluten based on the transparent circles. An unknown strain LB5 was chosen as the final fermentation strain on the basis of the preliminary fermentation evaluation. This strain was found to have a large colony circle with milk white color and folded in the edge. It’s a gram-positive bacteria which has the typical characteristics of bacillus. Amplification of 16 s r DNA products appeared in 1500 bp with fluorescence banding, and the strain was finally identified to be Bacillus amyloliquefaciens based on the gene sequence alignment.Bacillus amyloliquefaciens was used to perform the fermentation, and the concentration of glutamine peptides in the production was evaluated as a main index, based on which the optimum conditions of the fermentation by single factor and orthogonal test were obtained as follows: seed liquid with 109 cfu/m L bacteria, inoculum(v):gluten(m):water(v) =2:5:8(the substrate concentration is 33.33%), fermentation time 16 h, and fermentation temperature 40°C. In these conditions, the final yield of fermented wheat gluten is 88.10%, protein content is 80.26% with 52.67% water soluble protein, the concentration of water soluble glutamine peptides can be 204.62 mg/g, water soluble peptides content of fermented wheat gluten with molecular weight of 5 000~10 000 Da is 248.34 mg/g, 1000 ~ 5 000 Da 45.80 mg/g and < 1 000 Da 232.54 mg/g. Above all, fermented wheat gluten shows great advantages in the substrate concentration, glutamine peptide content and low molecular weight peptides component in comparison with the wheat gluten enzymatic hydrolysateMale C57/BL6 mice were used to evaluate the influence of the fermented wheat gluten on mice conditions, body weight change, DAI evaluation, colon state, colon length, colon histological analysis, serum cytokine levels and liver antioxidant effects in mice of colitis induced by DSS. Mice were randomly divided into five groups: Control group、DSS(Dextran sulfate sodium) group, Wheat gluten group, Wheat gluten enzymatic hydrolysate group and Fermented wheat gluten group. Compared with other colitis groups, mice in the fermented wheat gluten group had the following figures: moderating decline of body weight, reduced DAI score, slightly increased colon length, eased colon congestion status, reduced colitis histologic grading, alleviated epithelial cell damage, decreased serum TNF-α and IL-6 contents, increased IL-10 concentration, increased liver T-AOC and GSH-PX levels, decreased MDA level and improved ulcerative colitis status. Animal experiments confirmed that fermented wheat gluten has much more edge over the wheat gluten enzymatic hydrolysate in alleviating ulcerative colitis in mice inducess by DSS.