Effects of ohmic heating on interfacial, rheology and structure of aquafaba proteins and products

Abstract

Aquafaba, the viscous liquid obtained from cooking chickpeas, has emerged as a promising plant-based egg white substitute due to its foaming and emulsifying abilities. However, its native functional performance remains limited by low protein content and structural instability, which compromises its use in food systems such as meringues. This study aimed to evaluate ohmic heating (OH) as a clean-label and sustainable strategy to improve the functional properties of chickpea aquafaba, focusing on its structural, physicochemical, and rheological changes under different electric field intensities (20–50 V·cm⁻¹). OH at 20 V·cm⁻¹ significantly enhanced protein solubility (from 32.6 % to 46.4 %), increased free sulfhydryl content by 61 %, and improved viscoelastic moduli (G' and G") by over 35 %, resulting in denser, more elastic foams. Meringue porosity was reduced from 21.35 % (control) to 6.47 %, indicating a stronger structure. Conversely, higher intensities (≥ 40 V·cm⁻¹) led to excessive protein denaturation, reducing solubility by 47 %, increasing porosity to 33.61 %, and decreasing meringue cutting force from 7.76 N to 2.98 N. These results demonstrate that moderate OH intensity is effective in modulating protein structure to improve foam stability. The application of OH to aquafaba is unprecedented and represents a novel strategy to enhance plant-based protein systems for clean-label and sustainable food products.