Extraction Of Dietary Fiber From Soybean Dregs And Its Utilization In Bread

Fresh soybean dregs has been used as raw materials in this paper. The processing technic and physical chemistry after modification of soybean dietary fiber (SDF) have been studied, and the influence of additive SDF to Rheology charac- teristics of bread dough and quality of bread have been studied too. Scientific proof for the multipurpose use of SDF has been provided in this experiment. And we have obtained the follow conclusion:The technical parameters were optimized by single factors and orth- ogonal design experiment. The optimum conditions for extracting dietary fiber from soybean dregs is to extract at 95℃for 1.5 h, with acid liquor (pH=3) and a 1 : 10 sample weight/solvent volume ratio. And after the lye (pH=l 1, regulated with NaOH) at 40℃for 2 h, under the same weight /solvent volume ratio, then to filter and dry. At last ,we can obtain odour- less SDF. The experiment indicates that water-binding capacity, swelling capacity of SDF has been improved after ultramicro pulverization, and the conclusion is the smaller of granularity, the better of water-binding capacity, swelling capacity of SDF.We can obtain Microcrystallized Soybean Dietary Fiber (MSDF) with 91.43% cellulose content after procession with 6% HCL at 92℃for 25 min, and theswelling capacity, water-binding capacity of MSDF is 7.11 mL/g, 4.57 g/g separately. On the contrary, the relative index of SDF is 6.54 mL/g, 3.42 g/g.It can both increase the water absorption of high strength flour and low strength flour dough with addition of SDF or MSDF. And prolong the shaped time and steady time, and lower the degree of weakness, gel strength and extensibility, and increase the extension energy of the dough decreased. The Maximan resistance increased with the concentration of supplementation in low strength flour. It can decrease the Maximan resistance with addition of SDF and MSDF to high strength, which decreased with the concentration of supplementation, but in the 6% MSDF—supplemented dough, the Maximan resistance is increased. MSDF showed the better effect in flour than SDF.The result of baking tests indicated that bread baking quality was worsened with the increase of the dietary fiber added. Adding The optimum technologic parameters for the best quality of bread were obtained through orthogonal experiment: the adding quantity was 6% MSDF, the adding quantity of bread improver was 5%.