Preparation of Yeast Alkali-Insoluble Glucan by Enzyme-Alkali Methods

The alkali-insoluble glucan was isolated by enzyme-alkali method from waste beer yeast. The relative preparation conditions were as follows: 50 g yeast slurry added in 200 mL papain solution (its concentration as 20 mg/L), then after 36 h treatment at 55 ℃, the precipitate obtained through centrifugation, then added in 1.0 mol/L NaOH solution (solids: solution =1∶5), and then 3 h treatement at 45 ℃. Alkalic-insoluble glucan yield was 10.1 % and the content of glucan was as high as 92.6 %. Infrared spectra analysis showed that the product contained β-(1-3) glucan.