Microgels — An alternative colloidal ingredient for stabilization of food emulsions

• Microgels are soft porous colloidal particles made from cross-linked polymers.
• They exhibit structural stability, swelling behaviour, and stimulus-responsiveness.
• When adsorbed at an oil–water interface, the particles deform and interpenetrate.
• Biopolymer-based microgels are effective for rheological control and emulsification.
• Food microgel ingredients include casein, starch, hydrocolloids and whey proteins.

A gel is a conventionally defined on the macroscopic scale as a state of matter with a connected network of structural elements (polymers) and predominantly solid-like mechanical properties. When gel-like features are expressed on the microscopic scale, we get a special type of colloidal entity, the microgel, which possesses both polymeric and particle-like characteristics. Microgels are increasingly being viewed as valuable colloidal building blocks and stabilizing agents due to their deformability, surface activity, reversible swelling behaviour, and responsiveness to pH and temperature. For the case of biopolymer-based microgels, a novel functional application is the stabilization of food emulsions.