Rheological and molecular properties of water soluble (1,3) (1,4)-β-d-glucans from high-β-glucan and traditional oat lines

Water-soluble β-glucans were extracted, with a recovery yield of ∼70%, from five oat lines with increased β-glucan concentrations (up to 7.8% β-glucan) and one traditional oat line (4.4% β-glucan). The rheological properties of the extracted β-glucan gums were studied at concentrations of 0.25, 0.5 and 1% (w/w) over shear rates of 0–300 s−1. Statistically significant differences in the rheological properties of β-glucans were found among the oat lines when measured at 1% (w/w) β-glucan. β-glucan from the enhanced oat lines were more viscous (IA95258 had the highest and IA95205 the lowest viscosity) than those from the traditional line (Paul). The effect of concentration on apparent viscosity was accurately described by an exponential model for the six oat lines; however, the rate of change was significantly different among IA95258, IA95205 and Paul lines. Differences in viscosity between oat lines measured at the same β-glucan concentration and in rate of viscosity change with concentration might be explained by differences in peak molecular weight and polymer distribution.