Application of Ultrasound for the Modification of Techno-Functional and Physicochemical Properties in Cereal and Pseudocereal Protein Isolates: A Systematic Review

Cereal and pseudocereal protein isolates are increasingly investigated as sustainable food ingredients, although their limited solubility, interfacial activity, foaming performance, and hydration properties can restrict their technological application. This systematic review evaluated the effects of ultrasound on the physicochemical and techno-functional properties of protein isolates from cereals and pseudocereals. The review followed PRISMA guidelines and included 26 experimental studies identified from Scopus, Web of Science, Wiley, and Consensus. Owing to substantial heterogeneity in protein sources, sonication conditions, analytical methods, and outcome metrics, the evidence was synthesized narratively rather than by meta-analysis. Overall, ultrasound promoted aggregate disruption, particle-size reduction, partial unfolding, and greater exposure of hydrophilic and hydrophobic groups, which generally improved solubility, emulsifying activity and stability, foaming capacity and stability, water- and oil-holding capacities, and, in some studies, in vitro digestibility. The magnitude and direction of these effects depended on botanical origin and protein composition, as well as on pH, treatment time, acoustic power, and the sequence of combined processes. Treatments integrating ultrasound with pH shifting, heat, glycation, enzymatic modification, or high hydrostatic pressure often produced greater functional improvements than ultrasound alone. Ultrasound is therefore a promising approach for tailoring cereal and pseudocereal protein functionality, although standardized acoustic reporting and scale-up studies remain necessary.