Comparison of the solution properties of (1→3),(1→4)-β-d-glucans extracted from oats and barley

The solution properties of β-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 β-glucans. The crossover points of the moduli G′ and G″ in cuoxam solutions were different for the two β-glucans, i.e. 10 Hz for oat β-glucan and 1.5 Hz for barley β-glucan. The molecular weights of the β-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 β-glucans, which was higher for barley than for oat β-glucan.