Flow behavior and functional properties of barley and oat water-soluble β-D-glucan rich extractions

Flow characteristics and functional properties of water-soluble beta-glucan rich extractions prepared from hulled barley, hulless barley and oats were investigated. Rheological behavior was studied using a coaxial viscometer over shear rates of 3.0-1312 s(-1). The shear rate-shear stress data followed the power law and Herschel-Bulldey models. The flow behaviour index values varied from 0.31-0.97, indicating mildly to highly pseudoplastic nature of the aqueous solutions of beta-glucan rich extractions. The pseudoplasticity for the aqueous solutions increased with increasing concentration of extractions. The hulless barley beta-glucan rich extractions showed higher pseudoplasticity, consistency index, and yield stress values; absorbed less water and exhibited higher fat absorption and oil emulsifying properties than those of the hulled barley and oats. There was no discernible influence of fat contents on functional properties of the concentrates. Dough development time, arrival time, stability and softening of the dough were negligibly affected with addition of various beta-glucan rich extractions to the flours. Supplementation of beta-glucan rich extractions desirably increased the baking absorption of the flours. Bread with improved loaf quality could be obtained using various beta-glucan rich extractions upto a level of 1.00% (w/w), especially, from those of hulless barley cv. PNB 5.