Understanding Interfacial Rheology in Food Emulsions

Abstract

Nowadays, the evaluation of the rheological properties of interfaces represents an interesting tool to evaluate the formation of films, but it also allows to solve problems when formulating novel food colloid systems (emulsions or foams) in the food industry. Interfacial rheology describes the relationship between the deformation of an interface and the stresses exerted on it. Due to a variety of deformations of the interfacial layer (shear and expansion or compression), interfacial rheology is divided into the subcategories of shear and dilatational rheology: the dilatational and interfacial shear techniques are complementary, where dilatational results are related to emulsion formation and short-term stability and interfacial shear rheology is linked to long-term stability. Moreover, the interfacial film formation requires the essential presence of an emulsifier (low molecular weight emulsifiers, proteins, and polysaccharides). The role of these emulsifiers is the creation of the interfaces between the constituent fluids (immiscible). Thus, the formation and stabilization of systems with large interfacial areas greatly depend on the behavior of these interfaces during processing. In Chapter 3, we have presented major concepts related to bulk rheology. In this chapter, which is also the last chapter of Section I, we will present interfacial rheology as a potential tool to characterize the interfacial film. Therefore, this technique can be used in interfacial engineering to develop films with custom-designed properties in food science.