Effect of Modified Enzymatic Catalysis on the Extraction of Diosgenin from Dioscorea zingiberensis C. H. Wright

Multi‐enzymatic catalysis combined with acid hydrolysis is studied in order to enhance the efficiency of the enzymatic catalysis and reduce the mass transfer resistance from starch and cellulose in the extraction of diosgenin from Dioscorea zingiberensis C. H. Wright. The cellulase is modified by polyethylene to increase its optimal reaction temperature and pH value. The modified cellulase shows better thermostability and resistance to alkali. The modified cellulase, α‐amylase and β‐glycosidase are used to construct the multi‐enzyme and multi‐enzyme catalysis is used as a pretreatment process. Compared to primary industrial techniques including acid hydrolysis, spontaneous fermentation and enzymatic catalysis, conventional techniques are optimized by using multi‐enzymatic catalysis together with acid hydrolysis because of the higher reaction efficiency and lower levels of manipulation required. The purity of the product is more than 96 % with this technique, and the melting point is 205–207 °C. The diosgenin yield rate and the extraction rate reached are 2.43 % and 98 %, respectively. IR and ¹H NMR spectroscopy were used to confirm the structure of the product.