Biopolymer-based particles as stabilizing agents for emulsions and foams

The effectiveness of biopolymer-based particles as stabilizing agents of emulsified and aerated systems is attributable to a pair of contributory mechanisms — Pickering stabilization by adsorbed particles at the oil–water or air–water interface, and gel-like structuring of particles between droplets or bubbles. This review describes recent advances in the stabilization of emulsions and foams by edible particles of nanoscale and microscale dimensions. The biopolymer ingredients involved include common food proteins such as whey protein, soy protein and gelatin, and polysaccharides such as starch, cellulose and chitin. The diverse morphologies of the biopolymer-based entities range from rigid structures like dense spheres and polygonal crystals, through to semi-flexible fibres and deformable microgels. The clear message to be inferred from these studies is that a broadly consistent range of mechanistic behaviour has emerged — albeit with some basic questions remaining that offer exciting opportunities for future research.