Effects of Heat-moisture Treatment and α-amylase Enzymatic Treatment on the Physical and Rheological Properties of Waxy Barley Flour
This study analyzed the texture and rheological properties of waxy barley flour subjected to heat-moisture treatment and α-amylase treatment and examined how these treatments affect the processing suitability. Waxy barley flours were treated with a heat-moisture treatment (HM), α-amylase treatment (EZ), and their combined treatment (HM-EZ), and the transparency, textural properties, steady shear flow, and dynamic viscoelastic characteristics were analyzed. The HM and HM-EZ treatments maintained low transparency from the early storage stage and exhibited higher hardness and gel strength, suggesting enhanced gel-forming characteristics, as well as higher shear stress and apparent viscosity under shear conditions. In contrast, the EZ-treated samples showed improved initial dispersibility, increased adhesiveness and extensibility, and lower viscosity with higher flowability. Dynamic rheological analysis revealed elastic-dominant gel behavior in the HM and HM-EZ treatments, whereas the EZ treatment resulted in a lower storage modulus and more flexible viscoelastic behavior. These results show that the physical and rheological properties of waxy barley flour vary with the heat-moisture and α-amylase treatments, and suggest that tailored processing strategies can be used to design waxy barley-based food ingredients for specific applications.