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Five barley and two oat varieties grown in Korea were investigated for soluble, insoluble, and total (1→3), (1→4)-β-D-glucans. Total and insoluble β-glucans after extraction of soluble β-glucans with water were analyzed, and the soluble β-glucans were calculated as the difference between total and insoluble β-glucans. The total β-glucans in whole barleys were in a range of 3.3∼5.6%(average 4.4%), and those in pearled barleys were in a range of 3.5∼7.1%(average 5.2%). In whole barleys, on average, 54% of the β-glucans was soluble and in pearled barley 46%. Whole oats contained 3.1∼4.0% total β-glucan, and dehulling increased the groat β-glucan contents to 4.0∼4.8%. Oats demonstrated considerably higher β-glucan solubility of 84% than barley. β-Glucans in barley and oats were rapidly extracted at the beginning of the extraction and almost all of the β-glucans were extracted after 2∼3 hr extraction. As extraction temperature increased from 23℃ to 45℃, more soluble β-glucans were extracted. However, solubility of barley β-glucans decreased at a relatively high temperature of 65℃. Steam-cooking reduced the analytical solubility of barley and oat β-glucaus, while roasting seemed to render the β-glucans of barley more soluble.
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