Trends in structuring edible emulsions with Pickering fat crystals

The pace of development of edible Pickering emulsions has recently soared, as interest in their potential for texture modification, calorie reduction and bioactive compound encapsulation and delivery has risen. In the broadest sense, Pickering emulsions are defined as those stabilized by interfacially-adsorbed solid particles that retard and ideally prevent emulsion coalescence and phase separation. Numerous fat-based species have been explored for their propensity to stabilize edible emulsions, including triglyceride and surfactant-based crystals and solid lipid nanoparticles. This review explores three classes of fat-based Pickering stabilizers, and proposes a microstructure-based nomenclature to delineate them: Type I (surfactant-mediated interfacial crystallization), Type II (interfacially-adsorbed nano- or microparticles) and Type III (shear-crystallized droplet encapsulation matrices). Far from simply reporting the latest findings on these modes of stabilization, challenges associated with these are also highlighted. Finally, though emphasis is placed on food emulsions, the fundamental precepts herein described are equally applicable to non-food multicomponent emulsion systems.