Effect of barley β-glucan concentrate on oscillatory and creep behavior of composite wheat flour dough

Soluble dietary fibers can be used as valuable functional ingredients in food products because of their ability to influence the structural properties of the matrix in which they are embedded. The influence of barley β-glucan concentrate (BGC) addition (up to 10%) into standard wheat flour dough was evaluated through small and large deformation rheological measurements at selected temperatures (25-85 °C). Upon addition of BGC (⩽5%), significant increase in mixing time, dough stability and water absorption, and decrease in extensibility were recorded. The mechanical strength of the composite doughs lowered with increasing water content but it improved with BGC incorporation at constant moisture content within the studied frequency range (0.1-10 Hz). Both the elastic modulus (G′) and the complex viscosity (η∗) of doughs showed the temperature dependency within the frequency range tested. Time-temperature superposition of η∗-ω curves fitted well for up to 5% BGC incorporation when G′-ω failed at similar condition. Creep-recovery tests for BGC incorporated doughs recorded greater resistance to deformation. Differential scanning calorimetric measurement showed the protein denaturation temperature was influenced by both levels of wheat flour substitution by BGC and moisture content in the dough. Scanning electron microscopy used to study microstructure of doughs.