Oscillatory rheology and creep behavior of barley β-D-glucan concentrate dough: effect of particle size, temperature, and water content.

Abstract

Small amplitude oscillatory rheology and creep behavior of β-glucan concentrate (BGC) dough were studied as function of particle size (74, 105, 149, 297, and 595 μm), BGC particle-to-water ratio (1:4, 1:5, and 1:6), and temperature (25, 40, 55, 70, and 85 °C). The color intensity and protein content increased with decreasing particle size by creating more surface areas. The water holding capacity (WHC) and sediment volume fraction increased with increasing particle size from 74 to 595 μm, which directly influences the mechanical rigidity and viscoelasticity of the dough. The dough exhibited predominating solid-like behavior (elastic modulus, G' > viscous modulus, G″). A discrete retardation spectrum is employed to the creep data to obtain retardation time and compliance parameters, which varied significantly with particle size and the process temperature. Creep tests exhibited more pronounced effect on dough behavior compared to oscillatory measurement. The protein denaturation temperature was insignificantly increased with particle fractions from 107 to 110 °C. All those information could be helpful to identify the particle size range and WHC of BGC that could be useful to produce a β-d-glucan enriched designed food.