Effect of emulsifier on formation of zein based composite nanoparticles: Structure and stability

In this study, the novel zein/emulsifier/pectin ternary composite particles (Z/Rha/P and Z/Lec/P) were successfully fabricated using an anti-solvent co-precipitation method with either rhamnolipid (Rha) and lecithin (Lec) as the emulsifier. The results indicated that the emulsifier evidently affected the microstructures and properties of zein based composite nanoparticles. Hydrogen bonding, electrostatic interactions, and hydrophobic effects were the main forces of the ternary composite particles formed. Moreover, the thermal stabilities of the Z/Rha/P and Z/Lec/P were enhanced by increasing their corresponding Rha and Lec contents. Meanwhile, Z/Rha/P and Z/Lec/P exhibited their good stabilities at pH levels ranging from 2.0 to 9.0. Notably, under salt ion concentrations of 25–500 mM, the Z/Rha/P were extremely unstable, whereas the Z/Lec/P particles exhibited good stability. Overall, this work sheds light on designing an emulsifier-enhanced stable delivery system for bioactive compounds, offering the potential for further advancements in nanoparticle-based delivery technologies. • Zein/emulsifier/pectin ternary complex was formed via antisolvent coprecipitation. • Complex form was influenced by the emulsifier type and the zein/emulsifier ratio. • Complex was formed by hydrogen bonding, electrostatic and hydrophobic interactions. • The presence of an emulsifier in the complexes improved the thermal stability. • Zein/lecithin/pectin complex had good stability against pH and ionic strength.