Pickering foams stabilized by protein-based particles: A review of characterization, stabilization, and application

Stabilized by solid particles, Pickering foams have a much longer stability than traditional foams and have continued to gain interest in different applications in the last two decades. Protein-based particles with the typical amphiphilic structure are particularly suitable for developing Pickering foams due to their natural origin, low cost, excellent nutritional values, and potential health benefits. This review summarizes Pickering foams stabilized by protein particles and their complex particles conjugate with several biopolymers. Then, the main mechanisms controlling the foam stability are discussed to understand the complex behavior of Pickering foams better. Finally, the main applications and challenges of protein-stabilized Pickering foams are highlighted. To date, animal and plant proteins and their complexes with other biopolymers have been shown to stabilize Pickering foams effectively. The stabilization mechanism of Pickering foam includes irreversible adsorption and formation of a tightly-packed interfacial layer by adsorbed protein-based particles for preventing bubble shrinkage and gas diffusion, and accumulation at the Plateau borders or formation of gel-like network in the continuous phase by non-adsorbed protein-based particles for reducing drainage, as well as depletion stabilization. Each type of protein-based particle may exert excellent advantages in different applications. This review will provide theoretical guidance for efficiently developing innovative protein-stabilized Pickering foams for future applications in functional aerated foods.