In the present paper the phase equilibrium of  food solutions is discussed taking into account their highly complex character. Two types of food systems are considered. Firstly, fatty systems composed by a variety of triacylglycerols, fatty acids and alcoholic solvents, components occurring in the deacidification of edible oils by liquid-liquid extraction. Secondly, aqueous systems containing saccharides,  polycarboxylic acids, polyols, amino acids, salts, etc, components either naturally present in fruit juices, or artificially added to formulated food solutions. In the first case the highly multicomponent characteristic of vegetable oils is considered in the predictions procedure, while in the second one the partial dissociation of weak electrolytes and their chemical equilibrium are taken into account. The reported results indicate that the suggested approach might help in the designing and optimization of food processes.