Effects of Ultrasound-Assisted Protein Modification on the Functional and Nutritional Properties of Soy Protein Isolate

Abstract

Soy Protein Isolate (SPI) is among the most extensively utilized plant-derived proteins owing to its exceptional protein content, balanced amino acid composition, and versatile techno-functional properties. Nevertheless, the compact globular structure of native SPI limits its solubility, emulsification, foaming, gelation, and digestibility, thereby restricting its full industrial utilization. Ultrasound-assisted processing has emerged as an environmentally friendly, non-thermal modification technology capable of altering protein conformation through acoustic cavitation, resulting in structural unfolding, particle size reduction, exposure of hydrophobic groups, and improved intermolecular interactions. The present study employed a predictive research approach to evaluate the expected influence of ultrasound-assisted protein modification on the structural, functional, nutritional, antioxidant, and safety characteristics of Soy Protein Isolate. No laboratory experimentation or analytical measurements were performed. Instead, evidence-informed predictions were developed by integrating established scientific knowledge regarding soy protein chemistry, ultrasound processing mechanisms, protein functionality, and reported physicochemical characteristics available in the scientific literature. Four treatment conditions were comparatively evaluated: untreated native SPI (Control), mild ultrasound treatment (T₁), moderate ultrasound treatment (T₂), and optimized ultrasound treatment (T₃). The predictive assessment suggests progressive improvements in hydration properties, emulsifying ability, foaming capacity, gelation behavior, protein digestibility, antioxidant activity, and reduction of anti-nutritional factors with increasing ultrasound intensity under optimized processing conditions. Structural characterization is predicted to demonstrate increased surface hydrophobicity, exposure of sulfhydryl groups, reduced particle size, enhanced negative zeta potential, and partial conversion of α-helical structures into β-sheet and random coil conformations. Collectively, the predicted findings indicate that ultrasound-assisted modification represents a promising green processing strategy for improving the industrial functionality and nutritional quality of Soy Protein Isolate. The proposed predictive framework provides a scientific basis for future laboratory validation and commercial development of ultrasound-modified plant proteins for functional food and nutraceutical applications.