Pickering emulsion morphology: Stabilization and applications of double emulsions

Pickering emulsions (PEs) utilize solid particles with a hydrophilic surface and a hydrophobic core to stabilize the emulsion at the oil-water interface. Double emulsions (DEs) are intricate liquid systems made up of droplets from one liquid phase suspended in another liquid phase, which is also suspended in a third liquid phase. The use of solid particles as stabilizers decreases or eliminates the need for synthetic emulsifiers, allowing for cleaner label products. Pickering emulsion (PE) solid particles adsorb at the oil-water interface, providing a barrier that prevents droplets from coalescing. PEs are used to stabilize different food products including mayonnaise, cream-based products such as whipped cream and ice cream, beverages such as flavored milks, coffee-based drinks, and fruit juices. PEs are used to encapsulate bioactive components, flavors, and vitamins. They are incredibly stable against coalescence and can produce novel materials like microcapsules, colloidosomes, foams, and composite particles. They have garnered much interest and are prepared and applied using micro or nanoparticles, the major emulsion ingredients. This is due to the presence of molecules at the boundary of the oil and water phases that influences both creation and the characteristics of PEs, offering exceptional stability when contrasted with conventional emulsions that are supported by surfactants. When Pickering combined with bulk stabilization method are implemented together, the gelling of the aqueous phase appears to be a potential solution, characterizing its rheological and tribological performance and connecting it for their adoption in culinary applications and mouthfeel perception. This review discusses the factors that affect the structural persistence of PEs and how this PEs could be used to stabilize the double emulsion system. Droplet charge, emulsion color, flow behavior, viscoelastic properties, protein-based stabilizing techniques, rheology, and toxicity are the various properties of PEs that have been studied.