Effect of β-glucans on viscoelastic properties of barley kernels and their relationship to structure and soluble dietary fibre

The stress relaxation behaviour of barley kernels with differences in β-glucan was studied using the generalized Maxwell model for explaining the differences in quality. The relaxation moduli show that cultivar significantly affected the relaxation times (τ2 and τ3) and compressional viscosity (ηE2 and ηE3) of the 3 Maxwell elements and the pure elastic component (E0). These data were twice as high in cultivars with high β-glucans compared to low β-glucans. Protein and malt extract, as well as β-glucan, showed similar patterns to the corresponding cultivars from the same locations. Malt extract was correlated with both insoluble fibre (−0.71; P < 0.0007) and total fibre (−0.66; P < 0.006). High β-glucan cultivars presented relatively high soluble fibre, wort viscosity and presented higher relaxation times. Soluble fibre and the wort viscosity were correlated with relaxation times τ1, τ2, τ3. Also, β-glucans were correlated with τ3 and viscosity ηE3. The overall importance of the effect of β-glucans on viscoelasticity, malting and food quality as shown in this investigation is in agreement with earlier investigations.

► The β-glucans viscoelastic properties of barley were studied with the Maxwell model.
► The β-glucans viscoelastic properties of barley kernels were studied with the Maxwell model.
► Stress relaxation of barley kernels were related to β-glucan content and dietary fibre.