Lecithin

Lecithin can easily be extracted chemically (using [|hexane] ) or mechanically from readily available sources such as [|soy] beans. It has low solubility in water. In aqueous solution, its phospholipids can form either [|liposomes], bilayer sheets, [|micelles] , or lamellar structures, depending on and temperature. This results in a type of [|surfactant] that is usually classified as [|amphipathic]. Lecithin is sold as a food supplement and for medical uses. In cooking, it is sometimes used as an [|emulsifier] and to prevent sticking, for example in [|nonstick cooking spray].
 * Lecithin** is a generic term to designate any group of yellow-brownish fatty substances occurring in animal and plant tissues composed of [|phosphoric acid], [|choline] , [|fatty acids] , [|glycerol] , [|glycolipids] , [|triglycerides] , and [|phospholipids] (e.g., [|phosphatidylcholine] , [|phosphatidylethanolamine] , and [|phosphatidylinositol] ).

Properties and applications
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 non [|toxic] when ingested; some [|emulsifiers] can only be excreted via the [|kidneys]. Lecithin is used for applications in human food, animal feed, pharmaceutical, paint, and other industrial applications. Applications listed by one manufacturer, in addition to food applications, include: [|[4]]
 * 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 can also be used as a [|release agent] for [|plastics], an antisludge additive in motor lubricants, an antigumming agent in gasoline, and an emulsifier, spreading agent, and antioxidant in textile, rubber and other industries.

Use with food, and health effects
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 the food industry, it has multiple uses: 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. [|[4]] It can be used as a component of [|cooking sprays] to prevent sticking and as a releasing agent.