Future trends in the field of Pickering emulsions: Stabilizers, spray-dried microencapsulation and rehydration for food applications

Multiple food-grade Pickering emulsions are currently being developed to protect bioactive compounds during gastrointestinal digestion, ensuring their efficient delivery. Moreover, microencapsulation of Pickering emulsions by spray-drying can extend their shelf life. However, there are currently no reviews focusing on the effects of microencapsulation on the properties, morphology and efficiency before and after rehydration of Pickering emulsions. This article focuses on the recent progress in the development of food-grade Pickering emulsions, including detailed information of multiple stabilizers and principles and mechanisms for the formation of these emulsions, effects of spray-drying for the generation of microcapsules, and the stability of these delivery systems before and after rehydration, including also final remarks on the future prospects for their industrial widespread use. Key findings and conclusions : Food-grade particles (polysaccharides, proteins, polyphenols, fat crystals, agri-food by-products, composites etc.) extracted from multiple biomass can be used as stabilizers of Pickering emulsions. Microencapsulation process facilitates transportation and storage of Pickering emulsions, although spray-drying conditions (i.e. equipment, processing parameters, wall materials) significantly affect the properties of these microcapsules and their prospect applications. Future research must explore the use of emerging technologies to improve the formation and microencapsulation of Pickering emulsions that could be produced at industrial scale, while ensuring the bioavailability and protection of the encapsulated bioactive compounds. This will ensure an increased market uptake for the delivery of bioactive compounds and the development of nutraceuticals or functional foods. • The latest developments in food grade Pickering emulsions are summarized. • Spray-drying of Pickering emulsion benefits its transportation and storage. • Pickering emulsion microcapsules can be rehydrated and added to food matrices. • Future development trends of Pickering emulsion microcapsules are explored. • This review expands the application of Pickering emulsions in microcapsules.