Ultrasonication-induced structural and functional modification of starch in wheat flour

Abstract

This study investigated the effects of ultrasonication on the pasting, morphological, thermal, and rheological properties of wheat flour and dough, highlighting its potential as a green and sustainable processing technology. Wheat flour was treated with ultrasonic energy levels ranging from 40 to 140 kJ for 20 min. Rapid visco analysis (RVA) showed that at 40 kJ, peak viscosity increased from 1045.67 mPa·s (control) to 1259.00 mPa·s, and final viscosity rose from 2011.33 mPa·s to 2146.67 mPa·s, indicating enhanced gelatinisation. Differential scanning calorimetry revealed an increase in gelatinisation enthalpy (ΔH) from 8.03 J/g to 9.53 J/g, suggesting enhancement in molecular organisation. Rheological measurements demonstrated that ultrasonicated samples at 40 kJ and 100 kJ exhibited the lowest tan δ, suggesting improved elasticity and structural integrity. FTIR analysis confirmed intensified hydrogen bonding and improved gluten network formation. Low-field NMR and MRI analyses showed that ultrasonication significantly influenced water mobility and distribution within the dough. Moderate energy treatments (40 kJ to 100 kJ) enhanced water retention and network development. Scanning electron microscopy revealed surface roughness and partial granule disruption. These findings confirm that moderate ultrasonication enhances flour functionality by improving hydration, viscoelasticity, and thermal behaviour without the use of chemical additives. Ultrasonication offers an eco-friendly and energy-efficient approach for modifying wheat flour to improve the quality of sustainable flour-based products.