The purpose of this study was to examine the effect of the ingestion of barley breads baked using high β-glucan barley flour of different particle sizes on the postprandial glucose response. The results were collected using a randomized crossover study involving 13 healthy adults with normal fasting blood glucose levels. Each subject sampled three breads containing the same amount (50 g) of carbohydrates. The breads used were a wheat bread and two kinds of barley bread that were prepared with Beau Fiber, a β-glucan-rich barley flour, using large and small particle size samples (LBF and SBF), respectively. Blood glucose levels were measured before the meal and at 15, 30, 45, 60, 90, and 120 min after starting the meal. The same test was conducted twice beforehand, but with the subjects drinking 50 g of glucose in water instead of eating bread. Both the barley breads yielded lower glycemic index values and maximum blood glucose concentrations than the wheat bread. The glycemic index values of the barley breads made from LBF and SBF were 75.9 ± 7.0 and 68.2 ± 5.7 (mean ± standard error), respectively. The incremental area under the curve (IAUC) for SBF was significantly lower than that observed for the glucose solution, whereas no significant variation was observed for LBF. The tests confirmed that, compared to wheat bread, breads containing 30% high β-glucan barley flour yield lower postprandial blood glucose levels, and the reduction in the IAUC may be more prominent in SBF bread than in LBF bread.
Key Words：High β-glucan barley, Particle size, Blood glucose, Glycemic index |
