- published: 20 Dec 2015
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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.
Lecithin was first isolated in 1845 by the French chemist and pharmacist Theodore Gobley. In 1850, he named the phosphatidylcholine lécithine. Gobley originally isolated lecithin from egg yolk—λέκιθος lekithos is "egg yolk" in Ancient Greek—and established the complete chemical formula of phosphatidylcholine in 1874; in between, he had demonstrated the presence of lecithin in a variety of biological matters, including venous blood, bile, human brain tissue, fish eggs, fish roe, and chicken and sheep brain.