Harnessing ultrasonic power to optimize quinoa byproduct protein for sustainable utilization

The objective of this study was to elucidate the impact of ultrasonic treatment on quinoa by-product protein (QBP). Ultrasound treatment resulted in decreases in the moisture, lipid content, water activity, bulk and compact densities, and turbidity of the QBP. This treatment disrupted the compact protein structure and hydrophobic regions, thereby releasing a greater quantity of amino acids. Chemical analysis revealed that subjecting QBP aggregates to 400 W ultrasound transformed them into smaller and more uniformly distributed aggregates. Ultrasound significantly affected the secondary structure of QBP, increasing the relative proportions of α-helix and β-turn, while reducing β-pleated sheet and random coil proportions. Additionally, it altered the intrinsic fluorescence intensity and increased the sulfhydryl-group content. Notably, at 400 W, the protein exhibited optimal solubility, foaming properties, water and oil-binding capacity, and in vitro digestibility. These findings suggest that ultrasonic treatment can effectively enhance the quality and functional characteristics of quinoa protein byproducts, offering new perspectives for the comprehensive utilization of quinoa waste.