Enhancing the stability of oil-in-water emulsions by synergistic interplay between binary protein particles and starch nanocrystals

Abstract Oil in water (o/w) emulsions are ubiquitous in food systems, where the stabilization of a homogeneous biphasic texture is necessary. In this study, binary protein particles (CRPs) with hydrophilic shells (cod proteins) and hydrophobic cores (rice proteins) were fabricated as stabilizers of o/w emulsions. To circumvent their instability at the interface due to conformational changes, the CRPs were further reinforced by starch nanocrystals (SNCs) to form a secondary complex (CRP@SNCs). Results from cryo-scanning electron microscope and confocal laser scanning microscope confirmed the stable adsorption of SNC-reinforced CRPs on the biphasic interface with excessive SNCs as the spacers separating the adjacent oil droplets, leading to emulsions featuring both Pickering-type and steric-type stabilization. At the optimum SNCs/CRPs mass ratio, the emulsions showed undetectable phase-separation and negligible changes in droplet size during the tested storage for up to 28 days. Our study presents a facile strategy for innovating novel stabilization protocols for emulsions.