Colloidal lignin particle reinforces the stability of Pickering emulsions prepared with zein nanoparticle

Zein nanoparticle (ZNP) is at the forefront of research on Pickering emulsions, valued for its self-assembling and surfactant-free nature. Nevertheless, its emulsion stability is undermined by inadequate amphiphilicity. Colloidal lignin particle (CLP), characterized by its antithetical charge and amphiphilic nature, appears the promising for augmenting the stability of ZNP-based emulsion. This study meticulously investigated the impact of CLP on the colloidal properties and emulsifying performance of ZNP. The results revealed that electrostatic interactions between ZNP and CLP significantly mitigated the charge of ZNP and improved its hydrophilic/lipophilic balance. Under optimized conditions (1.0 wt% particle concentration, pH 4.0, 50% oil content), CLP notably reduced droplet sizes (41-225 μm) and enhanced the stability of ZNP-based Pickering emulsion, particularly at ZNP/CLP ratios of 6:4 and 5:5. In nature, CLP improved the stability ZNP-based Pickering emulsions via increased interfacial adsorption, enhanced steric hindrance, and reinforced viscous structure.