Ultrasound-assisted iron fortification of polished rice: effects on microstructure, cooking properties, and in vitro bioaccessibility

• Ultrasound modified rice grain microstructure without causing macroscopic damage. • Ultrasound increased rice iron content up to 41-fold. • Bioaccessible iron reached 2.27 mg/100 g after fortification. • Ultrasound reduced cooking time from 13.50 to 5.17 min. • Sensory attributes of rice were not significantly affected by the treatment.