The behaviour and susceptibility to degradation of high and low molecular weight barley beta-glucan in wheat bread during baking and in vitro digestion

The behaviour and susceptibility to degradation of a high molecular weight (HMW) and low molecular weight (LMW) barley beta-glucan in white bread during manufacture and in vitro digestion were investigated. The incorporation of both HMW and LMW barley beta-glucan resulted in stiffer dough, lowered loaf volume and height compared to the control. The HMW barley beta-glucan caused the greatest loss of dough and bread quality. Breads with HMW and LMW barley beta-glucan exhibited attenuated reducing sugars release (RSR) over a 300 min in vitro digestion compared to the control, with generally no difference between the breads. HMW barley beta-glucan was degraded during bread manufacture; however, degradation of the LMW barley beta-glucan was not apparent. An in vitro digestion did not result in any further degradation of the molecular weight (MW) of either barley beta-glucan. (c) 2006 Elsevier Ltd. All rights reserved.