Beta-glucan content was determined according to a modification of the method of McCleary and Holmes (1985). Mushroom samples are submitted with or without a pre-treatment with aqueous ethanol (50% v/v) solution, to a lichenase hydrolysis and further degraded by β-glucosidase. The released free glucose is measured spectrophotometrically at 510 nm against a blank necessary to subtract the free glucose eventually present in the sample. Lichenase acts at 40°C on mixed-links β(1→3) (1→4) and the hydrolysis of the other links β(1→4), β(1→3), β(1→6) is catalysed by β-glucosidase. The addition of β-glucosidase is carried out after separating the solid residue of lichenase action by filtration in order to avoid any interference due to other beta-linked saccharides (e.g. cellulose).