The effect of microwave-assisted hydrothermal treatment on physicochemical and functional properties of wheat, barley, and rye flours

The aim of this study was to investigate the effect of microwave-assisted hydrothermal process on color, solvent holding capacity, damaged starch content, resistant starch content, gelation and textural properties of wheat, barley, and rye flours. The hydrothermal treatment was conducted by adjusting the moisture content of the flours to 20, 25, 30, 35% following drying of the hydrated flours using a modified microwave oven until the moisture content fell below 8%. As a result, a general increase was observed in solvent (water, lactic acid, sucrose, and sodium carbonate) holding capacity, damaged starch content, b* value, chroma (saturation), redness, ΔE value, and gelatinization temperature of the flours regardless of the cereal type. The variations were more pronounced at higher initial moisture contents. On the contrary, the resistant starch content, L* value, whiteness, and breakdown viscosity decreased as a result of the treatment. The hydrothermal treatment resulted in an increase in maximum viscosity, setback viscosity, and gel hardness for wheat flour, whereas it led to a decrease in these parameters for treated barley and rye flours. Moreover, the impact of the treatment varied depending on the initial moisture content, with a more significant effect observed at moisture contents exceeding 25%.