Influence of water and barley beta-glucan addition on wheat dough viscoelasticity

The effects of the addition of two barley beta-glucan isolates (0.2-1.0% of wheat flour), differing in molecular weight, and water (53-63% in a poor breadmaking wheat flour, cv. Dion, and 58-68% in a good breadmaking wheat flour, cv. Yekora) on the viscoelastic properties of wheat flour doughs were investigated. A response surface model (CCF) was used to evaluate the effects observed on the dynamic and creep-recovery parameters of the dough. The evaluation was done separately for each combination of beta-glucan isolate (BG1 of similar to 10(5) Da and BG2 of similar to 2 x 10(5) Da) and flour type. Besides the contents of beta-glucan and water, the molecular size of the polysaccharide and the flour quality were important determinants of the dough's viscoelastic behavior. Compared to BG1, the higher molecular weight beta-glucan (BG2) brought about major changes on all the theological responses of the fortified doughs. The addition of appropriate levels of beta-glucans and water in the poor breadmaking cultivar (Dion) doughs could yield similar viscoelastic responses to those observed by a non-fortified good breadmaking quality flour dough (Yekora). (C) 2009 Elsevier Ltd. All rights reserved.