Abstract:Taking purple yam as the experimental material，the extraction technology of polysaccharides from purple yam by microwave pretreatment and ultrasonic extraction was optimized，and the inhibition effect on αglucosinase was studied by using the inhibition model of α-glucosinase.Through single factor and orthogonal test，the optimum condition were as follows：material-solvent ratio 1∶40 （g/mL），microwave power 300 W，microwave time 30 s，ultrasonic power 270 W，ultrasonic time 30 min.Under such conditions，the yield of polysaccharides was 11.12 %.The mass fraction of polysaccharides from purple yam polysaccharides powder was 45.80 % after deproteinization and ethanol precipitation.In the α -gluconidase inhibition test，the polysaccharide from purple yam showed a significant inhibitory effect，and the inhibition ability of α -gluconidase was weaker than that of Aqiabo.