Optimization the Extraction Process of Insoluble Dietary Fiber of Defective Jujube by Response Surface Method

The insoluble dietary fiber was extracted from defective jujube by enzymatic-gravimetric method. On the basis of single factor tests, according to the Box-Behnken central combination experimental design principles, taking the yield of insoluble dietary fiber as the response value, and designing the three factors and three levels of response surface experiments, the extraction process parameters of insoluble dietary fiber of defective jujube were optimized. At the same time, the mathematical models of various factors and the corresponding variable were established and analyzed. The results showed that, the optimum extraction conditions of insoluble dietary fiber of defective jujube were as follows: addition of α-amylase was 0.5%, addition of neutral protease was 0.6%, ratio of liquid to solid was 27 ∶1,hydrolysis temperature was 50 ℃, and hydrolysis time was 40 min. Under this condition, the yield of insoluble dietary fiber of defective jujube was up to 13.04%.