The mechanisms of thermal processing techniques on modifying structural, functional and flour-processing properties of whole-grain highland barley

The mechanisms underlying three thermal processing methods, namely hot-air drying, microwave irradiation, and heat fluidization, were systematically investigated to evaluate their effects on the structural, functional, and flour-processing properties of whole-grain highland barley. Starch granules were partially damaged when treated with hot-air drying and microwave irradiation. However, these granules were predominantly aggregated or encapsulated in proteins following heat fluidization. Accordingly, flour produced through heat fluidization exhibited the lowest relative crystallinity of 3.43 % and the greatest α → β shifts in secondary protein structures, compared to other treatments. These structural changes led to improved water/oil holding capacity, enhanced elastic property, reduced enthalpy of 4430 J/kg and breakdown viscosity of 0.24 Pa·s. Moreover, fresh noodles made from heat fluidization-treated highland barley exhibited superior textural features. Overall, heat fluidization could be a more effective method to modify the flour-processing properties of whole highland barley flour and enhance its applicability in the food industry.