Soybeans and egg. An emulsifying agent (emulsifiers help keep the fat from separating).
Commercial lecithin, as used by food manufacturers, is a mixture of phospholipids in oil. The lecithin can be obtained by water degumming the extracted oil of seeds. It is a mixture of various phospholipids, and the composition depends on the origin of the lecithin. A major source of lecithin is soybean oil. Lecithin, as a food additive, is also a dietary source of several active compounds: Choline and its metabolites are needed for several physiological purposes, including cell membrane signaling and cholinergic neurotransmission, and is a major source for methyl groups via its metabolite, trimethylglycine (betaine). Lecithin is used in many foods as an emulsifying agent (emulsifiers help keep the fat from separating). The richest natural sources of lecithin are from foods which are also high in fat, such as eggs and beef liver, but other foods such as peanuts, beef steak and some fruits and vegetables are lesser sources. Commercial lecithin is obtained as a by-product in the production of soybean flour and oil. The name is derived from the Greek word for egg yolk (lekithos), which is a rich source of lecithin. Commercial lecithin is purified and non-allergenic for people with soy bean or chicken allergies. Lecithin chemically is phosphatidylcholine, a phospholipid that is part of the cell structure in both animals as plants. This results in a type of surfactant that usually is 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, as a food additive, is also a dietary source of several active compounds: Choline and its metabolites are needed for several physiological purposes, including cell membrane signaling and cholinergic neurotransmission, and is a major source for methyl groups via its metabolite, trimethylglycine (betaine). This is one of the reasons why soy lecithin is used as an additive in processed foods, medicines and supplements; it helps give these products a smooth, uniform appearance. Composed of choline, fatty acids, glycerol, glycolipids, phospholipids, phosphoric acid and triglycerides lecithin was originally isolated from egg yolk. Today, it is regularly extracted from cottonseed, marine sources, milk, rapeseed, soybeans, and sunflower. Lecithin is a fat that is essential in the cells of the body. It can be found in many foods, including soybeans and egg yolks. Lecithin is taken as a medicine and is also used in the manufacturing of medicines. Lecithin is used for treating memory disorders such as dementia and Alzheimer ’s disease. It is also used for treating gallbladder disease, liver disease, certain types of depression, high cholesterol, anxiety, and a skin disease called eczema. Some people apply lecithin to the skin as a moisturizer. Soy Lecithin Fact Sheet C OMPOSITION Soy lecithin consists of three types of phospholipids; phosphatidylcholine (PC), phosphatidylethanolamine (PE) and phosphotidylinositol (PI). It is extracted from soybean oil and is generally used as a natural emulsifier or stabilizer in various food applications.  Lecithin is a food additive that comes from several sources — one of them being soy. It is generally used as an emulsifier, or lubricant, when added to food, but also has uses as an antioxidant and flavor protector. Like many food additives, soy lecithin isn’t without controversy.
https://en.wikipedia.org/wiki/Lecithin http://www.food-info.net/uk/qa/qa-fi68.htm https://en.wikipedia.org/wiki/Lecithin https://draxe.com/what-is-soy-lecithin/ http://www.webmd.com/vitamins-supplements/ingredientmono-966-LECITHIN.aspx?activeIngredientId=966&activeIngredientName=LECITHIN http://www.soyconnection.com/sites/default/files/Soy-Lecithin-Fact-Sheet.pdf http://www.healthline.com/health/food-nutrition/is-soy-lecithin-good-or-bad-for-me
what is lecithin used for in food