Chitosan-coated phytoglycogen for preparation of biocompatible Pickering emulsions

The development of edible particles for the preparation of biocompatible Pickering emulsions is of great significance. Phytoglycogen (PG) is a type of carbohydrate nanoparticles found in nature. However, due to its high hydrophilicity, few studies on the preparation of Pickering emulsions with PG have been reported. Surface coating of charged particles with oppositely charged polymers is a simple and efficient method to improve surface wettability of particles and facilitate their adsorption at the interface of oil/water. In this work, an oil-in-water Pickering emulsion stabilized by all-natural phytoglycogen/chitosan (PC) complex particles made of PG and chitosan (CS) was developed. The PG was coated by CS via electrostatic interaction for improving the interfacial activity and hydrophobicity. When compared to PG or CS alone, the PC complex particles were shown to emulsify a range of biocompatible oils in water, allowing the formation of more stable and smaller emulsion droplets. This method enabled the stabilization of biocompatible Pickering emulsions for more than six months, as well as the stabilization of the resultant Pickering emulsions against variations in pH and ionic strength. As an example, the prepared Pickering emulsion can effectively protect encapsulated β-carotene against for light and heat. The combination of renewable and edible PG with CS presents unique prospects for the production of promising Pickering emulsions for food, pharmaceutical, or cosmetic applications.