Hydrodynamic and ultrasonic cavitation physically modifies the milk protein concentrates with improved functionality

Abstract

Hydrodynamic cavitation (HC) and ultrasonic (US) treatments were applied to modify milk protein concentrates (MPCs) and enhance their techno-functional properties. Treatments were conducted at 6 MPa for 0–30 min (HC) and 20 kHz at 200–600 W (US). Both cavitation techniques significantly improved emulsifying, foaming, and solubility characteristics of MPCs. The emulsifying activity increased by up to 110% at 600 W, while foaming capacity improved by over 200% at 6 MPa, following 20 min treatments. A marked increase in protein solubility (up to 99.6%) and reduction in particle size (from 4.82 µm in control to 0.94 µm for US-treated and 1.35 µm for HC-treated samples) indicated disaggregation and unfolding of protein aggregates. Spectroscopic analysis further confirmed alterations in the secondary structure, with reduced amide I intensity and slight band broadening, signifying partial unfolding and exposure of hydrophobic residues. These structural modifications directly correlated with improved surface activity, resulting in enhanced emulsifying and foaming behavior. SDS-PAGE analysis confirmed the absence of protein degradation, indicating that cavitation induced conformational rather than chemical changes. Overall, the findings substantiate that cavitation treatments effectively unfolded protein structures and exposed hydrophobic groups, leading to improved functional performance. This study highlights the potential of scalable cavitation processes for producing high-performance, clean-label dairy ingredients suitable for industrial food applications.