ABSTRACT
In the kitchen, emulsified systems and emulsions are frequently encountered, because most traditional food ingredients, such as animal and plant tissues, contain both water and fat. More recently, the definition of an emulsion was standardized by the International Union for Pure and Applied Chemistry: A fluid colloidal system in which liquid droplets and/or liquid crystals are dispersed in a liquid. Concerning surfactants, the simple distribution that was considered between oil and water is simplistic, as the surfactant molecules can self-associate when their concentration is high enough. There are other possibilities, such as liposomes or bilayers, but one should remember that all such pictures have to be interpreted, because representing surfactant molecules with such heads and tails is simplistic; in general, the “size” of the head is only a few chemical bonds long, whereas the tails have a length of 10 to 20 covalent bonds.
