Comparison of the solution properties of (1 -> 3),(1 -> 4)-beta-D-glucans extracted from oats and barley

The solution properties of beta-glucan isolated from whole grains of oats and barley were studied by viscosity and oscillatory measurements both in water and in aqueous cuoxam, an ammoniacal Cu(OH)(2)/CUCl-solution. The viscosity measurements of water solutions show stronger shear thinning for oat than for barley beta-glucans. The crossover points of the moduli G' and G '' in cuoxam solutions were different for the two beta-glucans, i.e. 10 Hz for oat beta-glucan and 1.5 Hz for barley beta-glucan. The molecular weights of the beta-glucans were similar. Therefore, the difference in solution properties seems to be related to the difference in structure. This difference is revealed by the ratio DP3:DP4 of the main building blocks of beta-glucans, which was higher for barley than for oat beta-glucan. (c) 2007 Swiss Society of Food Science and Technology. Published by Elsevier Ltd. All rights reserved.