Effect of barley β-glucan molecular size and level on wheat dough rheological properties

The effect of adding low (105 Da) or high (2.03 × 105 Da) molecular weight barley β-glucans in two wheat flours of different breadmaking quality were studied. Mechanical spectra and creep–recovery analysis data within (low stress) and out (high stress) of the linear viscoelastic region were obtained. The results revealed that the rheological behavior of β-glucan-enriched doughs depend on concentration and molecular weight of the polysaccharide as well as on the flour type used. Addition of β-glucan increased the G′ values of the good breadmaking quality flour doughs, whereas decreased the G′ of the poor quality wheat cultivar. Supplementation with β-glucans increased the resistance to deformation, flowability and elasticity of the doughs under low stress. Significant correlations between frequency sweep and creep–recovery parameters of optimally developed doughs from both flours were found. The addition of β-glucan in the dough recipe of the poor breadmaking wheat flour may result in similar rheological responses to those obtained from a non-fortified good breadmaking quality wheat flour.