Theme XIV: Lipids

Definition of Phospholipids. Content, importance and function. Lecithin, composition, functions. Sources of commercial lecithin.

Phospholipids are essential components of many animal and plant cells and have been categorized as lecithin, cephalin and sphingomyelin, being the lecithins those with pharmaceutical application. These include the lipoidal structures containing phosphorus in their molecules.

When lecithins are fully hydrolyzed can produce two molecules of fatty acid, a molecule of glycerin, a phosphoric acid molecule and a basic nitrogen compound which is usually choline.

The fatty acids obtained by hydrolysis from lecithins are oleic, palmitic and stearic. Choline is a member of the vitamin B complex, its function in the body is to prevent the accumulation of fat in the liver and its acetylated derivative (acetylcholine) is released at the parasympathetic nerve endings when stimulated to control the transmission of pulses through cholinergic synapses.

Commercial lecithin is obtained from eggs, brain tissue and soybeans.

Properties of lipids

Uses of lipids

Lipids

Fixed oils and fats

Wax

Sterols

Definition of Phospholipids. Content, importance and function. Lecithin, composition, functions. Sources of commercial lecithin.