The properties and applications of lecithin

　　Lecithin is a multi-purpose food ingredient that primarily functions as an emulsifier and dispersing agent.It's CAS Registry Number is 8002-43-5.Lecithin’s surface-active property can be attributed to its chemical composition: a complex mixture of phospholipids, glycolipids, carbohydrates and triglycerides. As such, lecithin interacts well with other substances, such as proteins, lipids and carbohydrates.


lecithin


　　1.Properties　　Lecithin has emulsification and lubricant properties, and is a surfactant. It can be totally metabolized (see Inositol) by humans, so is well tolerated by humans and nontoxic when ingested; some emulsifiers can only be excreted via the kidneys.
　　Lecithin is used for applications in human food, animal feed, pharmaceuticals, paints, and other industrial applications.
　　Applications include:
　　*In the pharmaceutical industry, it acts as a wetting, stabilizing agent and a choline enrichment carrier, helps in emulsifications and encapsulation, and is a good dispersing agent. It can be used in manufacture of intravenous fat infusions and for therapeutic use.
　　*In animal feed, it enriches fat and protein and improves pelletization.
　　*In the paint industry, it forms protective coatings for surfaces with painting and printing ink, has antioxidant properties, helps as a rust inhibitor, is a colour-intensifying agent, catalyst, conditioning aid modifier, and dispersing aid; it is a good stabilizing and suspending agent, emulsifier, and wetting agent, helps in maintaining uniform mixture of several pigments, helps in grinding of metal oxide pigments, is a spreading and mixing aid, prevents hard settling of pigments, eliminates foam in water-based paints, and helps in fast dispersion of latex-based paints.
　　*Lecithin also may be used as a release agent for plastics, an anti sludge additive in motor lubricants, an anti gumming agent in gasoline, and an emulsifier, spreading agent, and antioxidant in textile, rubber, and other industries.
　　2.Application　　*Food additive
　　The nontoxicity of lecithin leads to its use with food, as an additive or in food preparation. It is used commercially in foods requiring a natural emulsifier or lubricant.
　　In confectionery, it reduces viscosity, replaces more expensive ingredients, controls sugar crystallization and the flow properties of chocolate, helps in the homogeneous mixing of ingredients, improves shelf life for some products, and can be used as a coating. In emulsions and fat spreads it stabilizes emulsions, reduces spattering during frying, improves texture of spreads and flavour release. In doughs and bakery it reduces fat and egg requirements, helps even distribution of ingredients in dough, stabilizes fermentation, increases volume, protects yeast cells in dough when frozen, and acts as a releasing agent to prevent sticking and simplify cleaning. It improves wetting properties of hydrophilic powders (e.g., low-fat proteins) and lipophilic powders (e.g., cocoa powder), controls dust, and helps complete dispersion in water.Lecithin is the emulsifier that keeps cocoa and cocoa butter in a candy bar from separating. It can be used as a component of cooking sprays to prevent sticking and as a releasing agent. In margarines, especially those containing high levels of fat (>75%), lecithin is added as an 'anti spattering' agent for shallow frying.
　　*Dietary supplement
　　Lecithin is marketed as a dietary supplement. As such no claims may be made that it useful to treat or prevent a disease or condition. Because it containsphosphatidylcholines, it is a source of choline, an essential nutrient.Clinical studies have shown benefit in acne, in improving liver function, and in lowering cholesterol, but clinical studies in dementia and dyskinesias have found no benefit.