Variation in total and soluble β-glucan content in hulless barley: effects of thermal, physical, and enzymic treatments.

Total and soluble β-glucan content and effects of various treatments of barley grain on extractability and molecular characteristics of soluble β-glucan were studied. Four types of hulless barley (normal, high amylose, waxy, and zero amylose waxy) from 29 registered and experimental genotypes were analyzed. For each, moisture, protein, amylose, 100 kernel weight, starch, β-glucan (total and soluble), β-glucanase activity, and slurry viscosity were determined. Significant differences in total β-glucan were observed among the groups, with average values of 7.49%, 6.86%, 6.30%, and 4.38% for high amylose, waxy, zero amylose waxy, and normal barley, respectively. The extractability of β-glucan in high amylose barley was relatively low (20.6−29.7%) compared to that in normal (29.8−44.3%), zero amylose waxy (34.0−52.5%), and waxy (36.7−52.7%) barley genotypes. Viscosity of barley flour slurries was affected by the content of soluble β-glucans, β-glucanase activity, and molecular weight of β-glucans. Hydrotherma...