Food emulsions

Only the simplest foods are present as one continuous phase. In practice, much of the texture and other complex behavior of food systems arises from phase heterogeneity. A common and relatively simple form of heterogeneity is when the food is present as a dispersed system-small particles of one material (or phase) in a second continuous phase [1]. We are concerned with that subset of dispersed systems where one of the phases is lipid and the other aqueous, i.e., emulsions. Some examples of water-in-oil food emulsions include milk, ice cream mix, mayonnaise, salad dressings, soups, beverage emulsions, and flavor emulsions. The classic definition of an emulsion requires both phases to be liquid but in foods this definition is frequently expanded to include systems where one or more phases are solid. It is possible to make an emulsion with either a lipid or an aqueous dispersed phase and this distinction largely governs the overall properties of the emulsions (e.g., a lipid-continuous system will disperse poorly in water, and have a low conductivity and a greasy mouthfeel). However, in this work we will focus on aqueous-continuous emulsions.