Study On Improvement Of Soluble Dietary Fiber And Protein By Fermentation On Soybean Dregs

Soybean Dregs is the by-product of soybean’s processing which the utilization rate ofit is low and generally be used as animal feed, but the soybean dregs has lots of nutrients,especially the dietary fiber and protein. This paper focused on the preparation of solublesoybean dietary fiber by fermentation with the soybean dregs as the material and theAspergillus Niger and Trichoderma viride as the mixed bacteria, the optimization of thefermentation technology by Response Surface Methodology (RSM) was studied as well.What’s more, this paper also studied on products which were based on the formerexperiment with Fiber Cellulase after freeze drying, then by using Beer Yeast secondaryfermentation and the optimization of the fermentation technology by Response SurfaceMethodology (RSM) as well. The main results were as follows:1. The results showed that the nutrients of Soybean Dregs contained water7.46%,protein17.25%, fats7.13%, ash3.78%, and dietary fiber61.87%(soluble dietary fiber4.08%, the rate of dietary fiber is6.59%; insoluble dietary fiber57.79%, the rate of dietaryfiber is93.41%).2. The study was taken liquid and mixed fermentation method to making solubledietary fiber from soybean dregs, then the results by significant of the single factor andResponse Surface Methodology’s (RSM) equation coefficient showed that the order offactors which affected fermentation conditions was fermentation time, fermentationtemperature and the strain rate. Among them, the fermentation time and strain rate,fermentation time and fermentation temperature, strain rate and fermentation temperaturedoes significant interaction. In this experiment, the optimum conditions of the fermentationtechnology were as follows: the rate of Asperillus Niger and Trichoderma viride was2:1(inoculums size), fermentation time45h, fermentation temperature26.4℃, inoculationamount10%and the initial pH value6. Under the conditions, the yield of the solubledietary fiber (SDF) reached to22.76%, which accounted for43.21%of the soluble dietary(DF), and the content of SDF increased by4.46times. With the freeze-drying, the productshas the characteristics of small particle size, he uniform texture, exquisite taste, lightyellow color and light aroma.3. Taken the products which were based on the former experiment with FiberCellulase after freeze drying, then by using Beer Yeast secondary fermentation and theoptimization of the fermentation technology with the Response Surface Methodology (RSM) method as well. Then the results by significant of the single factor and ResponseSurface Methodology’s(RSM) equation coefficient showed that the influence sequence offermentation conditions was fermentation time, fermentation temperature and the feedingquantity. Among them, fermentation time and fermentation temperature, the fermentationtime and feeding quantity, feeding quantity and fermentation temperature does significantinteraction. The results showed that the optimum conditions of the fermentation technologywere as follows: fermentation temperature26℃, fermentation time36h, feeding quantity8%and the initial pH value6. Under the conditions, the yield of the protein reached to29.95%, the content of protein increased by74.07%which was larger than the originalproduct.