Physicochemical and functional properties of barley β-glucan as affected by different extraction procedures

Four methods were evaluated for extraction of beta-glucan from barley. Gum pellets obtained by respective methods were examined for yield, purity and various physicochemical and functional characteristics. Highest yield and recovery was found in samples that were extracted by hot water treatment. This method also removed the maximum impurities from gum pellets and contained highest amount of soluble fibre, while alkali-extracted sample contained highest amount of insoluble fibre. All samples contained an appreciable amount of calcium and phosphorus. Extracted pellets had good water retention and foaming capacity. A significant variation in extraction methods was observed with respect to water binding capacity and foaming capacity. However, the same level of foaming stability was observed in all extraction methods. Alkaline and acidic extraction methods adversely affect the viscosity properties of the samples. A significant affect of extraction methods was also observed on colour parameters of beta-glucan. A negative correlation exists between foaming capacity and viscosity, whereas a positive correlation observed between soluble fibre and viscosity.