Lecithin is a generic term to designate any group of yellow-brownish fatty substances occurring in animal and plant tissues, which are
amphiphilic - they attract both water (and so are
hydrophilic) and fatty substances (
lipophilic), and are used for smoothing food textures, dissolving powders (emulsifiers), homogenizing liquid mixtures, and repelling sticking materials. Lecithins are usually
phospholipids, composed of
phosphoric acid with
choline,
glycerol or other
fatty acids usually
glycolipids or
triglyceride.
Glycerophospholipids in lecithin include
phosphatidylcholine,
phosphatidylethanolamine,
phosphatidylinositol,
phosphatidylserine, and
phosphatidic acid.