Abstract: To improve the hypoglycemic ability of Morchella polysaccharide in vitro,α -Amylase inhibition rate was detected with single factor test and response surface methodology.The multiple regression equation model of α-amylase inhibition rate of Morchella polysaccharide modified products was also established.The predicted model indicates that the optimum reaction conditions are as follows:materialliquid ratio is 1∶8.55,pH is 7.09,and the reaction time is 3.02 h at 47.8 ℃.Under the same conditions,three parallel experimental results indicate that the α-amylase inhibition rate of the modified product of hydrogen peroxide oxidation of Morchellapolysaccharide is 16.30%±1.22%,and the relative error between experiment and prediction of the model is 0.11%.The α-amylase inhibition rate is17.16 times of that of the unmodified. In this case,the inhibition rates of sucrase,maltase and α-glucosidase were 78.13%±5.09%,16.48%±3.27% and 21.40%±3.81% respectively,which were 1.07,1.64 and 1.22 times higher than those before modification.Compared with acarbose,the α-amylase inhibition rate,maltase inhibition rate and α-glucosidase inhibition rate of the modified product of Morchella polysaccharide increased by 1.44,1.63 and 1.88 times respectively,while the sucrase inhibition rate was not significantly different from acarbose（P>0.05）.The product modified by hydrogen peroxide oxidation of Morchella polysaccharide shows infrared absorption characteristics of polysaccharide,and significantly improves the inhibitory effect on glycosidase,and improves its hypoglycemic ability in vitro.

Key words: Morchella polysaccharide, hydrogen peroxide degradation, glycosidase inhibitors