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Effects of roasting on barley β-glucan, thermal, textural and pasting properties

Abstract:

Different hulled barley cultivars were subjected to roasting in hot sand (280 °C) and the effects on β-glucan extractability, physico-chemical, thermal and pasting properties were studied. The grain puffed upon roasting and grain hardness and colour difference Δ E were significantly lowered. The roasted barley flour had significantly higher water absorption and water solubility index. The cultivars DWR-28, RD-2503 and PL-172 had the highest total β-glucan content (up to 5.47%). Roasting brought about a decrease in the soluble β-glucan content in all the cultivars and this decrease ranged from 4.9 to 25.3%. The β-glucan extractability was not affected by the roasting process but roasting lowered the ratio of soluble to insoluble β-glucan content by 8.1-41.9%. Roasting significantly affected the pasting and thermal properties of the flours, together with an increase in the cooked starch content that ranged from 28.8 to 43.1%. © 2010 Elsevier Ltd.