Abstract:Using Hericium erinaceus as the material， the alkali method， complex enzyme method， and ultrasound-assisted enzyme method were used to extract insoluble dietary fiber （IDF） from H. erinaceus. In addition， the effects of the three extraction methods on the structure， physicochemical， and functional properties of IDF were compared. Results showed that the highest yield of IDF was obtained with the alkali method（42.95±1.43）%. Scanning electron microscopy results showed that IDF extracted by ultrasound-assisted enzyme method and alkali method had a large number of folds and loose porous structure. Fourier-transform infrared spectroscopy showed that the IDF extracted by the three methods had similar peak shapes， all showing polysaccharide characteristic structures. In terms of physicochemical properties， the alkali method [water holding capacity （6.47±0.05） g/g] and ultrasound-assisted enzyme method [swelling capacity （13.54±0.22） mL/g]had better hydration properties for IDF， with the ultrasound-assisted enzyme method contributing to maintaining good color of IDF， while the complex enzyme method [oil holding capacity （2.91±0.14） g/g] facilitated better oil holding capacity of IDF. Regarding functional properties， IDF extracted by all three methods effectively adsorbed cholesterol and glucose. Specifically， IDF obtained by ultrasound-assisted enzyme method exhibited the highest adsorption capacity for cholesterol and glucose， as well as excellent antioxidant activity. In conclusion， IDF extracted by ultrasound-assisted enzyme method had a loose porous structure， good physicochemical properties， and functional properties， making it an effective method for extracting IDF from H. erinaceus.