Extraction of Water-Soluble Dietary Fiber from Soybean Residue by Compound Enzymatic Method and Its Application in Edible Film

Soluble dietary fiber（SDF） was extracted from soybean residue by expanding-assisted complex enzyme hydrolysis, and then made into edible film. The extraction and film-forming conditions of bean residue SDF were optimized by orthogonal tests. The results showed that the optimum extraction conditions were as followed: ratio of bean dregs to distilled water 1∶30（g∶mL）, cellulase addition 30 g/L（calculated by distilled water volume）, extraction time 2 h, and protease enzymolysis p H 9. The best film forming conditions were: soybean dregs SDF 1.0 g, CMC-Na1.0 g, sodium alginate 1.5 g and glycerol 4.5 mL. Under the above conditions, the prepared soybean residue edible film had smooth and stable properties, with water dissolution rate of 0.098 mg/s and water drip time of 12 060 s.