The effect of barley β-glucan fiber fractions on starch gelatinization and pasting characteristics

We evaluated the effects of extraction treatment on the yield and composition of beta-glucan-rich fiber fractions from barley, and the subsequent influence of these fractions on the thermal properties and pasting behavior of starch pastes. Extraction treatment affected the yield of barley beta-glucan (BBG) fiber fraction, and beta-glucan recovery efficiency (P < 0.05). The level of inclusion of these fractions in starch-water dispersions had a significant influence on the pasting characteristics such as peak viscosity (PV), breakdown (BEI), and final viscosity (FV) development (as determined using a Rapid Visco Analyser). Substitution of 5% wheat starch with the fiber fractions decreased PV, BD, and FV in comparison to the control starch (P < 0.05). Substitution of 5% wheat starch with BBG fiber fraction resulted in a decrease in enthalpy (J/g) values compared with the control (P < 0.05). A reduction in pasting characteristics may be associated with a reduced enthalpy of starch gelatinization and retention of the integrity of the starch granule. The reduction in PV may also indicate a reduced degree of starch granule swelling.