Emulsions Containing Oleogels

Lipid colloidal systems such as emulsions, emulgels, and oleogels provide pleasant texture in foods. Emulsions are colloidal systems with at least two immiscible phases stabilized by the addition of ingredients that may or may not reduce the tension at the water-oil interface. Oleogels are structures produced from the gelation of liquid oil, using ingredients capable of physically imprisoning the oil in a three-dimensional network. A relevant aspect is to understand how oleogels behave in the presence of water, in order to contribute to their incorporation into food matrices. In this context, this chapter presents the combination of these two lipid systems as a strategy for the production of stable emulsified systems. These emulsions are formed using high-energy (rotor-stator, high-pressure homogenization, ultrasound) and, in most processes, there is the addition of emulsifiers as in the production of conventional emulsions. However, in this strategy, the organic phase, continuous or dispersed, is gelled by the addition of oleogelators, making this system promising in replacing trans-fat in processed foods, in addition to being a vehicle for bioactive compounds and improving the oxidative stability of unsaturated oils.