Lecithin consists of one molecule of glycerol, esterified with two molecules of fatty acids; one of these fatty acid may be unsaturated and other saturated. It contains phosphoric acid and a nitrogenous base – choline. Two forms of lecithin, alpha lecithin, and beta lecithin are described. Alpha lecithin has the phosphoric acid and choline attached to the third carbon atom (alpha carbon atom) of glycerol; beta lecithin has the phosphoric acid and choline attached to the second carbon atom (beta carbon atom) of glycerol. The structure of lecithin is given below: