A systematic review on innovations in co-stabilized protein-hydrocolloid Pickering emulsions: mechanistic insights, tailored properties, and functional applications

Pickering emulsions, stabilized by solid particles at oil-water interfaces, have garnered increasing interest as promising alternatives to conventional surfactant-based emulsions. Recent research shows that combining proteins and hydrocolloids as co-stabilizers enables unique interfacial architectures and improved long-term stability. In this systematic review, we synthesize the mechanism of action governing protein-hydrocolloid co-stabilization based on a comprehensive and structured assessment of studies retrieved from major scientific databases (PubMed, Scopus, and Web of Science). We categorize co-stabilizing agents into 18 mechanistic groups, defined according to their protein nature, hydrocolloid type, interfacial behavior, and contribution to the continuous phase, to relate structure to function, and we link interfacial adsorption/viscoelastic film formation and bulk gelation to droplet size distributions, rheology, environmental tolerance, and release behavior. The co-stabilization strategies involve interfacial interactions between amphiphilic proteins and hydrocolloids, producing robust, viscoelastic interfacial films and gel-like continuous phases. Collectively, the review identifies consistent trends, such as improved pH and thermal stability, enhanced encapsulation of bioactives, and tailored texture, across food and pharmaceutical applications. Emerging opportunities include the use of plant- and marine-derived biopolymers, advanced processing, and computational modeling for predictive formulation design. By consolidating mechanistic understanding with functional outcomes, this review provides a clear framework for rationally designing next-generation co-stabilized Pickering emulsions for sustainable and high-performance applications.