Study on the Optimization of the Soluble Dietary Fiber Content of Soybean Residue by Steam Explosion Pretreatment

Abstract

Because a large amount of soybean residue(SR) what is the byproduct of tofu and soymilk industries is produced annually in the world and is a byproduct with a rich nutritional profile, particularly in proteins, fibers, lipids, and bioactive components, a lot of researchers intensify the study on the SR and the processing and utilization of its have attracted more and more attention due to the increased consumption of SR in recent years. Especially the soluble fiber of SR lowers blood cholesterol and triglyceride levels by binding to cholesterol and helping to pass it out of the body, therefore, the composition proportion of soluble components in dietary fiber is an important factor affecting its physiological function. Steam explosion (SE) is a kind of physical method recently used in food pretreatment. In this study, the insoluble dietary fiber of SR converted to soluble dietary fiber by SE treatment and increased the content of soluble dietary fiber, and optimized the condition of SE treatment processing by response surface methodology(RSM). The results showed that the optimum conditions was: moisture content of 76.3%, steam explosion time of 88S?steam explosion pressure of 1.7MPa; on the conditions?the content of SDF was 36.5%. Through the analysis on the physicochemical properties of SE treated SR in the optimum condition, determined that water solubility of SR increased significantly, while swelling capacity, oil and water holding capacities decreased after SE treatment.