Self-Assembled Egg Yolk Peptide Micellar Nanoparticles as a Versatile Emulsifier for Food-Grade Oil-in-Water Pickering Nanoemulsions

Abstract

Pickering emulsions stabilized by food-grade particles have garnered increasing interest in recent years due to their promising applications in biorelated 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 (EYPNs), self-assembled from the food-derived, amphiphilic egg yolk peptides, as an edible particulate emulsifier. As natural peptide-based nanoparticles, the EYPNs have a small particle size, intermediate wettability, high surface activity, and deformability at the interface, which enable the formation of stable Pickering nanodroplets with a mean dynamic light scattering diameter below 200 nm and a polydispersity index below 0.2. This nanoparticle system is versatile for different oil phases with various polarities and demonstrates the easy control of nanodroplet size through tuning the microfluidization conditions or the ratio of EYPNs 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 EYPNs 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.

How Do Charged End-Groups on the Steric Stabilizer Block Influence the Formation and Long-Term Stability of Pickering Nanoemulsions Prepared Using Sterically Stabilized Diblock Copolymer Nanoparticles?

“…11,[19][20][21] In recent years, there has been growing interest in Pickering nanoemulsions, which comprise droplets of less than approximately 200 nm in diameter. [22][23][24][25][26][27][28][29][30] In contrast to conventional macroemulsions, nanoemulsions are much less prone to gravitational creaming or sedimentation. [31][32] Furthermore, their significantly higher surface area confers greater activity when used in various cosmetics, 33 drug delivery, [34][35] food 29,[36][37] and agrochemical formulations.…”

“…[22][23][24][25][26][27][28][29][30] In contrast to conventional macroemulsions, nanoemulsions are much less prone to gravitational creaming or sedimentation. [31][32] Furthermore, their significantly higher surface area confers greater activity when used in various cosmetics, 33 drug delivery, [34][35] food 29,[36][37] and agrochemical formulations. 31,[38][39][40] However, many nanoemulsions suffer from Ostwald ripening.…”

Utilization of Nanotechnology to Improve the Handling, Storage and Biocompatibility of Bioactive Lipids in Food Applications

“…These types of structured emulsions can be produced entirely from food grade ingredients and can be used to encapsulate bioactive lipids. Food grade nanoparticles that are suitable for used as emulsifiers in Pickering emulsions include nanocellulose, nanochitin, nano-starch, protein nanoparticles, and SLNs [51][52][53][54]. The bioactive lipids can be encapsulated within the oil droplets or within the nanoparticles used to stabilize them.…”

“…Pickering emulsions stabilized by chitosan hydrochloride/carboxymethyl starch nanogels have been used to encapsulate β-carotene, which improved the stability of the carotenoid to UV exposure and heating [93]. Pickering emulsions stabilized by egg yolk peptides and micellar nanoparticles were found to be stable to spray drying conditions and to oil leakage during storage [54]. Similarly, encapsulation of β-carotene in Pickering emulsions stabilized by gliadin nanoparticles and gum arabic has been shown to improve the resistance of the carotenoid to pH, salt, heat, and light [94].…”

Adsorption and foaming properties of edible egg yolk peptide nanoparticles: Effect of particle aggregation

“…Recently, we reported that the food-derived, amphiphilic egg yolk peptides (EYPs) can be used to create edible colloidal nanoparticles via the “bottom-up” self-assembly approach ( Du et al., 2019 ). The amphiphilic EYPs are prepared by the controlled enzymatic hydrolysis of purified defatted egg yolk protein, a by-product obtained after lecithin extraction from egg yolk.…”