Effect of β-D-glucan concentrate and water addition on extensional rheology of wheat flour dough

Abstract

Extensional properties of wheat flour and composite wheat flour/β-glucan concentrate (BGC) doughs were studied as function of water content (58–70 mL/100 g flour) and β-D-glucan concentrate (2.5–10 g/100 g). Water absorption increased linearly with increasing BGC level in the composite dough whereas the dough extensibility reduced significantly at similar condition. The peak pressure value of the inflated dough increased and the bubble height decreased with increasing BGC concentration, whereas a reverse trend was observed during plasticization of dough by water addition irrespective of BGC concentration. Henky strain of dough at break point decreased with incorporation of BGC and the value ranged between 0.98 and 1.71. The strain hardening index was calculated from stress–Henky strain data which obtained directly from biaxial measurement and the value increased with BGC incorporation compared to wheat flour dough. A linear relationship was found between extensibility and Henky strain of dough at break point that could be used to convert data from empirical to fundamental rheological measurement or vice-versa. All those information would be helpful to design and quality control of β-D-glucan enriched food products.