Improvement of Functional Properties and In Vitro Digestibility of Durum Wheat, Chickpea, and Amaranth Flours Using Power Ultrasound

Ultrasound technology has emerged as a promising non-thermal approach for modifying the structural and functional properties of food matrices. However, its impact on starch digestibility remains insufficiently understood, particularly in complex systems such as cereal, legume, and pseudocereal flours. This study evaluated the effect of power ultrasound on the functional properties and in vitro digestibility of durum wheat (DWF), chickpea (CF), and amaranth (AF) flours. Flours were treated using an ultrasonic probe (20 kHz, 60% amplitude) for 10 and 20 min while maintaining the sample temperature at 15 °C. Structural and functional properties were assessed, including color, morphology, water absorption, FT-IR spectra, pasting behavior, thermal properties, and starch fractions. Ultrasound induced structural modifications, including starch granule disruption and increased surface roughness. Lightness increased in DWF, CF, and AF, although the magnitude of the response differed among flour types. Water absorption improved in DWF but decreased in CF and AF. FT-IR spectra suggested molecular rearrangements, while viscoelastic and thermal analyses showed increased viscosity in DWF and CF and reduced viscosity in AF. Ultrasound also modified starch fractions and in vitro starch digestibility in a flour-dependent manner, reflecting the distinct structural responses of cereal, legume, and pseudocereal starches to acoustic cavitation. Overall, ultrasound modified the functionality of flour and starch digestibility in a matrix-dependent manner, supporting its potential as a clean-label technology for tailoring the functional properties of different flour matrices.