lecithin science definition

A fatty substance present in most plant and animal tissues that is an important structural part of cell membranes, particularly in nervous tissue. It consists of a mixture of diglycerides of fatty acids (especially linoleic, palmitic, stearic, and oleic acid) linked to a phosphoric acid ester. Lecithin is used commercially in foods, cosmetics, paints, and plastics for its ability to form emulsions.