Based on central composite design and response surface methodology,the optimal extraction of Polygonatum polysaccharides by cellulase was investigated.Experiment factors and levels were firstly selected by one factor tests.Independent variables were the enzymolysis temperature,the pH of extracting media and the ratio of liquid,and dependent variable was extraction rate of polysaccharides in Polygonatum.Nolinear mathematic models were used to analysis the relationship between independent and dependent variab...