Self-assembled egg yolk peptide micellar nanoparticles as a versatile emulsifier for food-grade oil-in-water pickering nanoemulsions

Pickering emulsions stabilized by food-grade particles have garnered increasing interest in recent years due to their promising applications in bio-related fields such as foods, cosmetics, and drug delivery. However, it remains a big challenge to formulate nanoscale Pickering emulsions from these edible particles. Herein, we show that a new Pickering nanoemulsion that is stable, monodisperse and controllable can be produced by employing the spherical micellar nanoparticles (EYPN), self- A ssembled from the food-derived, amphiphilic egg yolk peptides, as an edible particulate emulsifier. As natural peptide-based nanoparticles, the EYPN have small particle size, intermediate wettability, high surface activity, and deformability at the interface, which enable the formation of stable Pickering nanodroplets with a mean DLS diameter below 200 nm and a PDI below 0.2. This nanoparticle system is versatile for different oil phases with various polarities and demonstrates easy control of nanodroplet size through tuning the microfluidization conditions and/or the ratio of EYPN to oil phase. These food-grade Pickering nanoemulsions, obtained when the internal phase is an edible vegetable oil, have superior stability during long-term storage and spray-drying, based on the irreversible and compact adsorption of intact EYPN at the nanodroplet surface. This is the first finding of a natural edible nano-Pickering emulsifier that can be used solely to make stable food Pickering nanoemulsions with the qualities of simplicity, versatility, low cost, and the possibility of controllable and mass production, which make them viable for many sustainable applications.