lecithin

lecithin
/les"euh thin/, n.
1. Biochem. any of a group of phospholipids, occurring in animal and plant tissues and egg yolk, composed of units of choline, phosphoric acid, fatty acids, and glycerol.
2. a commercial form of this substance, obtained chiefly from soybeans, corn, and egg yolk, used in foods, cosmetics, and inks.
[1860-65; < Gk lékith(os) egg yolk + -IN2]

* * *

Any of a class of phospholipids (also called phosphatidyl cholines) important in cell structure and metabolism.

They are composed of phosphate, choline, glycerol (as the ester), and two fatty acids. Various fatty acids pairs distinguish the various lecithins. Commercial lecithin, a wetting and emulsifying agent used in animal feeds, baking products and mixes, chocolate, cosmetics and soap, insecticides, paint, and plastics, is a mixture of lecithins and other phospholipids in an edible oil.

* * *

also called  Phosphatidyl Choline,  

      any of a group of phospholipids (phosphoglycerides) that are important in cell structure and metabolism. Lecithins are composed of phosphoric acid, cholines, esters of glycerol, and two fatty acids; the chain length, position, and degree of unsaturation of these fatty acids vary, and this variation results in different lecithins with different biological functions. Pure lecithin is white and waxy and darkens when exposed to air. Commercial lecithin is brown to light yellow, and its consistency varies from plastic to liquid.

      The term lecithin is also used for a mixture of phosphoglycerides containing principally lecithin, cephalin (specifically phosphatidyl ethanolamine), and phosphatidyl inositol. Commercial lecithin, most of which comes from soybean oil, contains this mixture and, commonly, about 35 percent neutral oil. It is widely used as a wetting and emulsifying agent and for other purposes. Among the products in which it is used are animal feeds, baking products and mixes, chocolate, cosmetics and soaps, dyes, insecticides, paints, and plastics.

* * *


Universalium. 2010.

Игры ⚽ Поможем написать реферат

Look at other dictionaries:

  • Lecithin — is any of a group of yellow brownish fatty substances occurring in animal and plant tissues, and in egg yolk, composed of phosphoric acid, choline, fatty acids, glycerol, glycolipids, triglycerides, and phospholipids (e.g., phosphatidylcholine,… …   Wikipedia

  • Lecithin — Lec i*thin, n. [Gr. le kiqos the yolk of an egg.] (Physiol. Chem.) A complex, nitrogenous phosphorized substance widely distributed through the animal body, and especially conspicuous in the brain and nerve tissue, in yolk of eggs, and in the… …   The Collaborative International Dictionary of English

  • Lecithīn — Lecithīn, ist nach Gobley der phosphorhaltige Körper der Höhner u. Karpfeneier, eine neutrale Substanz, welche beim Behandeln mit Mineralsäuren u. Alkalien Öl , Margarin u. Glycerinphosphorsäure liefert …   Pierer's Universal-Lexikon

  • Lecithīn — Lecithīn, ein phosphorhaltiger Körper, der in Tier und Pflanzenzellen weitverbreitet vorkommt und besonders im Gehirn, in Nerven, Samen, im Blut, namentlich bei hochgradiger Leukämie, im Eiter, in der Galle, Milch, im Eidotter, Kaviar, in Hefe,… …   Meyers Großes Konversations-Lexikon

  • Lecithin — Lecithīn, fettähnliche Substanz, charakteristischer Bestandteil des Gehirns, der Nerven und des Eidotters, überhaupt im Tier und Pflanzenkörper verbreitet, knetbare, nicht deutlich kristallinische Masse, quillt mit Wasser; zerfällt durch Säuren… …   Kleines Konversations-Lexikon

  • Lecithin — ⇒ Phospholipide …   Deutsch wörterbuch der biologie

  • lecithin — fatty substance found in the yolks of eggs (among other places), 1861, from Fr. lécithine (coined 1850 by N.T. Gobley), from Gk. lekithos egg yolk, + chemical suffix INE (Cf. ine) (2). Gk. lekithos is of unknown origin …   Etymology dictionary

  • lecithin — [les′i thin] n. [< Gr lekithos, yolk of an egg + IN1] any of several phosphatides found in nerve tissue, blood, milk, egg yolk, soybeans, corn, etc.: used in medicine, foods, cosmetics, etc. as a wetting, emulsifying, and penetrating agent …   English World dictionary

  • Lecithin — Lecithine (deutsch: Lezithine, altgriechisch: λέκιθος = Eidotter) ist der klassische Name für eine Gruppe chemischer Verbindungen, die so genannten Phosphatidylcholine. Dabei handelt es sich um Lipide, genauer Phospholipide, die sich aus… …   Deutsch Wikipedia

  • lecithin — Traditional term for 1,2 diacyl sn glycero 3 phosphocholines or 3 sn phosphatidylcholines, phospholipids that on hydrolysis yield two fatty acid molecules and a molecule each of glycerophosphoric acid and choline. In some varieties of l., both… …   Medical dictionary

Share the article and excerpts

Direct link
… Do a right-click on the link above
and select “Copy Link”