Assembly mechanism of egg white protein-carboxymethyl cellulose based on surface patch binding effect: Interfacial complexation regulates high internal phase emulsion stability

Abstract

Surface patch binding (SPB)-based protein-polysaccharide assembly complexes are a feasible and eco-friendly way to generate emulsifiers, and their unique interfacial complexation, formed post-emulsification, makes emulsion stability control effortless. We explored the assembly of egg white protein (EWP) with carboxymethyl cellulose (CMC) at varying degrees of substitution (DS). The results demonstrated that EWP, functioning as polyampholytes, assembled with CMC through SPB, driven by hydrophobic and electrostatic interactions. The higher DS improved the surface hydrophobicity of assembly complexes, facilitating their adsorption and rearrangement at the oil-water interface, which led to superior interfacial complexation. These interfacial complexes developed stronger steric hindrances that curbed droplet aggregation, boosted droplet friction, and minimized relative displacement, thus providing high internal phase emulsion (HIPE) multi-scenario stability. This study offers an effective strategy for achieving customized material properties through targeted modulation of interfacial complexation.