Effects of Microwave Irradiation on Water-soluble Polysaccharides of the Fruiting Body of Hericium erinaceum

To examine the applicability of microwave irradiation for the extraction of polysaccharides in the fruiting body of Hericium erinaceum, structures of polysaccharides obtained by microwave irradiation in water were compared to those obtained by hot water extraction using conventional external heating. A major polysaccharide obtained by microwave irradiation in water (140°C, 5 min) was (1→3;1→6)-β-D-glucan rich in (1→3) linkages, whereas polysaccharides obtained by hot water extraction using conventional external heating (100°C, 6 h) were fucogalactan and (1→3;1→6)-β-D-glucan rich in (1→6) linkages. In the case of microwave irradiation in water, fucogalactan was suggested to be depolymerized during heating. Microwave heating in water has an advantage over the conventional external heating for extraction of β-glucan rich in (1→3) linkages from the fruiting body of H. erinaceum.