Ohmic heating dominates and ultrasound modulates aquafaba structure: A combined approach to design stable plant-based...

This study investigated the individual and combined effects of ohmic heating (OH, 20 and 40 V cm^-1) and ultrasound (US, 425 and 850 W) on the chemical, physicochemical, and technological properties of chickpea aquafaba (AF) and its emulsions.

Structural analyses demonstrated that OH was the predominant factor modulating protein unfolding, whereas US acted as a secondary modulator, dispersing aggregates and altering the extent of exposure of hydrophobic and sulfhydryl groups. At moderate OH intensity (20 V cm^-1), combined treatments (particularly 20/425) promoted higher surface hydrophobicity, increased solubility, greater availability of sulfhydryl groups and more negative zeta potential. These modifications translated into improved emulsion properties, with smaller and more homogeneous oil droplets, higher viscosity and consistency indices, stronger gel-like behavior (G' ≫ G″), and enhanced physical stability (TSI < 4). By contrast, high OH intensity (40 V.cm^-1), especially when combined with high-power US (40/850), induced excessive aggregation, reduced protein solubility and impaired interfacial coverage, and also led to unstable emulsions. Confocal microscopy confirmed that moderate treatments produced dense interfacial protein films, whereas severe conditions resulted in flocculation and coalescence.

Overall, results highlight that OH drives protein modifications, whereas US fine-tunes structural rearrangements, and that controlled intensities are essential to enhance AF functionality in plant-based emulsions. © 2026 The Author(s). Journal of the Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.