Pickering Emulsions Simultaneously Stabilized by Starch Nanocrystals and Zein Nanoparticles: Fabrication, Characterization, and Application

Using two types of colloidal particles having natural origins to synergistically stabilize Pickering emulsions is essential for food, cosmetics, and pharmaceutics, especially when neither particle can stabilize the Pickering emulsions alone. The use of two natural stabilizers avoids the complicated surface treatments of particles and the introduction of poisonous or harmful chemicals. In this work, we report an all-natural Pickering emulsion stabilized synergistically by starch nanocrystals and zein protein nanoparticles. Our result shows that the electrostatic interaction between the two types of particles greatly affects their assembled structure at the oil/water interface, which is closely related to the emulsion stability. Specifically, particle bilayers could form with oppositely charged particles at the interface to endow the emulsion with improved stability. As a demonstration, the resultant Pickering emulsions effectively carry β-carotene and have high stability against high temperatures and ultraviolet radiation. This type of all-natural Pickering emulsion is a promising tool to protect and deliver liposoluble bioactive components.