Naturally occurring protein/polysaccharide hybrid nanoparticles for stabilizing oil-in-water Pickering emulsions and the formation mechanism

In this study, we reported for the first time that the natural protein/polysaccharide hybrid nanoparticles (PPH NPs) with a diameter of ∼ 129 nm, originating from Lactobacillus plantarum fermented cheese whey, could act as green-based NPs for stabilizing Pickering emulsions. Characterizations of PPH NPs showed that the negative-charged PPH NPs were composed of ∼ 37.7% total protein and ∼ 7.3% polysaccharide bearing several functional groups, such as -OH, -NH, -COOH, etc.; and displayed excellent emulsifying capacity in preparing oil-in-water Pickering emulsions. The obtained emulsions exhibited gel-like behavior with excellent stability against the variation of pH, ionic strength, and temperature. Confocal observations showed that PPH NPs effectively adsorbed and anchored at the oil-water interface, thus creating the steric hindrance to inhibit droplet coalescence. This research is of importance in developing novel and biocompatible Pickering stabilizers with outstanding performance, as well as enable a versatile design of stable Pickering emulsions suitable for food industries.