Physicochemical properties, structural characterization, and in vitro binding capacity of polysaccharide fractions from the fruiting bodies of Lentinula edodes

Lentinan exhibit a diverse array of biological activities. However, studies investigating the in vitro binding capacity of Lentinan are still lacking. The physicochemical and structural properties, as well as the in vitro binding capacity of Lentinan and its isolated fractions, were comparatively investigated. This investigation focused on in vitro binding of lipids, cholesterol, and bile acid salts. The crude polysaccharide (P20) was extracted using high-pressure hot water extraction and alcohol precipitation with 20% ethanol from L. edodes fruiting body. P20 was then deproteinized to obtain the polysaccharide fraction (P20-1), which was separated using DEAE-52 cellulose anion-exchange columns to yield three polysaccharide fractions (P20-1A, P20-1B, and P20-1C). Among all the polysaccharide fractions, P20-1A had the highest polysaccharide content (54.33%) and P20 had the better emulsifying activity. Deproteinization and column separation decreased the viscosity and increased the water solubility of the fractions. P20 and P20-1 consisted mainly of glucose, galacturonic acid, and mannose, while P20-1A and P20-1B consisted mainly of glucose, galactose, and mannose, and P20-1C consisted mainly of glucose, galacturonic acid, mannose, and galacturonic acid. P20-1A exhibited the best in vitro binding capacity, which may be attributed to its highest polysaccharide content, lower viscosity and viscosity-average molecular weight, higher galactose content, and did not contain glucuronic acid and galacturonic acid. Additionally, its loose and porous microscopic morphology provided more interaction area. This study presents scientific evidence and research progress on the potential use of P20-1A as a functional food supplement for individuals with hyperlipidemia.