Rheological properties of barley β-glucan

Health benefits of cereal beta-glucan are linked to its high viscosity. Although viscosity of beta-glucan gum solutions has been reported previously, there are conflicting reports about its behavior at elevated temperatures. Therefore, the viscosity behavior of barley beta-glucan gum obtained in a pilot plant (PP) or in a laboratory (LAB) was determined at different shear rates (1.29-129 s(-1)) and temperatures (0.1-75 degrees C) in this study. Viscosity decrease with temperature was demonstrated for both gums and activation energy E-a was calculated from the Arrhenius equation. None of the fresh gum solutions exhibited thixotropic behavior at <= 1% (w/w) concentration, but the measurement demonstrated that increased shear rate is not applicable to polymer solutions of low viscosity. Information about rheological properties of beta-glucan will lead to better understanding of its behavior under physiological and processing conditions. (c) 2004 Elsevier Ltd. All rights reserved.