The invention belongs to the field of 
processing agricultural products, and particularly relates to a preparation method of 
dioscorea opposita thunb slime 
polysaccharide and 
resistant starch. The preparation method of 
dioscorea opposita thunb slime 
polysaccharide and 
resistant starch comprises the following steps: washing and peeling fresh 
dioscorea opposita 
thumb, protecting color, 
slicing, crushing, homogenizing, putting homogenate into a high-pressure pulsed 
electric field for extraction, adding water into the treated dioscorea opposita 
thumb homogenate and performing high-speed 
centrifugation, and centrifuging 
starch residues at the lower layer for three times; respectively collecting supernatant and lower-layer 
starch residues obtained through repeated 
centrifugation; filtering the centrifuged supernatant through a molecularly imprinted membrane and eluting with water, to obtain a dioscorea opposita 
thumb slime 
polysaccharide solution, concentrating and 
drying to obtain dioscoreaopposita thumb slime polysaccharide, adding water into the lower-layer 
starch residues and performing membrane 
filtration, preparing a starch 
emulsion after filtering, performing pressure-heating treatment in an 
autoclave and then adding pancreatic 
amylase and 
pullulanase for enzymolysis, performing 
enzyme denaturing and performing 
refrigeration and 
ageing, hot-
air drying, pulverizing and screening to obtain the dioscorea opposita thumb 
resistant starch.