Molecular Weight, Solubility and Viscosity of beta-Glucan Preparations from Barley Pearling Byproducts

Abstract

beta-Glucan, the representative dietary fibre component of barley, has received much attention, primarily due to its nutritional significance. In this study, beta-glucans prepared from barley pearling byproducts were characterized with respect to their molecular weight, solubility and viscosity. Following the initial alkaline extraction, the crude beta-glucan extract (45% purity) was further purified to approximately 90%. The isolated beta-glucans exhibited a wide molecular weight range with peak molecular weight of less than 1 x 10(6) daltons. Solubilities of crude and purified beta-glucans in water were lower than that of beta-glucan in the native barley pearling byproducts. However, the aqueous solubility of purified beta-glucan from pearlings was substantially higher than that of commercial beta-glucan. Compared to the latter, purified beta-glucan exhibited low apparent viscosity in aqueous solutions.