Dietary fibre fractions in hulled and naked winter oat grain: effects of cultivar and various agronomic factors

The dietary fibre fractions in two winter cultivars each of hulled oats and naked oats grown on three sites under different agronomic conditions in two years were studied. Overall, soluble nonstarch polysaccharides (NSP) represented some 540 g kg(-1) of total NSP, and this did not vary greatly among cultivars. There was a significant (P < 0.001) positive relationship between total and soluble NSP. Within cultivars there was much greater variability in the concentrations of beta-glucans than in soluble NSP, and overall there was no relationship between the concentrations of the two related fractions. Oat cultivar and factors such as year and site where grown significantly (P < 0.01) affected soluble NSP contents. There were some indications that environmental factors such as temperature, rainfall and sunshine hours may have been responsible for the apparent effects of site and year. On a dehulled basis, traditional hulled cultivars contained significantly (P < 0.05) more beta-glucans than the naked types, and the results suggest that selection of oats for dietary or plant-breeding purposes should be based on beta-glucan rather than soluble NSP concentrations. (C) 2000 Society of Chemical Industry.