Ultrasound‐Assisted Hydration and Its Effect on the Antinutrient Factors and Structural Properties of Pearl Millet

Abstract

This study analyzed the effect of ultrasound (US)‐assisted hydration on the hydration behavior, antinutrient factors, and structural properties of pearl millet. Treatments included conventional soaking (CS) for 240, 480, and 720 min; US‐assisted hydration at 455 W for 30, 60, and 90 min; and a combination of CS and US (240 min + 455 W, 60 min). The highest hydration index was observed in CS for 720 min (34.553 ± 0.60%), US for 90 min (34.907 ± 0.72%), and CS + US for 60 min (35.652 ± 0.43%). Pasting temperatures of CS and US‐treated samples (70°C–75°C) were higher than those of native grains (55.29 ± 0.02°C). A significant change in peak viscosity was noted, with the highest viscosity observed in the US‐treated samples. US‐assisted hydration reduced phytate by 50% and tannin by 61%. Microscopic images showed structural degradation, and crystallinity decreased by CS and US hydration, with the lowest crystallinity (31.62%) in US‐assisted hydration for 90 min. These results indicate that US‐assisted hydration significantly affects millet's physicochemical properties, structural characteristics, and antinutritional components.