Direct measurement of the interaction of model food emulsion droplets adhering by arrested coalescence

A new instrument called a Cantilevered-Capillary Force Apparatus is used to characterize the interaction of two individual solid-in-oil-in-water (S/O/W) emulsion droplets. The droplets studied are intended to act as a model for understanding the physics of food emulsions and other similar suspensions of droplets. The formation of capillary bridges between emulsion droplets is identified as the physical mechanism for the adhesion of droplets with a high volume fraction of solid particles. This mechanism is supported quantitatively by direct measurements of the magnitude of the force required to separate the droplets. It is also demonstrated that some rheological properties of the individual emulsion droplets can be investigated in situ.