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Lecithin

Lecithin is a complex mixture of phosphatides produced from a variety of vegetable and animal sources. Lecithins are typically mixtures of diglycerides of fatty acids linked to the choline ester of phosphoric acid, and are classed as phosphoglycerides or phosphatides (phospholipids). The mixture of phosphatides referred to in the trade as lecithin is a group of phospholipids composed of the following structural members: glycerol, fatty acids, phosphoric acid, and amino alcohols and carbohydrates, respectively. Examples of the phosphatides are phosphatidyl choline (PC), phosphatidyl ethanolamine (PE), phosphatidyl inositol (PI), phosphatidic acid (PA) and acetylated phosphatidyl ethanolamine (aPE). Lecithins and modified lecithins are widely used in the food and pharmaceutical industries as digestible solubilizers and emulsifiers. Lecithins are obtained from various animal or vegetable sources, such as soybeans or egg yolk, and comprise a mixture of phospholipids and triglycerides, as well as lesser amounts of compounds such as glycolipids, carbohydrates, fatty acids, and/or sterols. Vegetable lecithins are derived from crude vegetable oils or fats, in which the lecithins are present as a colloidal solution. They are usually removed in a degumming step in which lecithin is precipitated, e.g. by injection of steam into the oil or fat or by injection of water or an aqueous solution. Lecithin obtained from soy bean is referred to as soy bean lecithin. The main constituents of soybean lecithin are phosphatidyl choline, phosphatidyl ethanolamine, phosphatidyl inositol, phosphatidyl serins, phosphatidyl acid, lysophospholipids, and phytoglycolipids. Although lecithin can also be derived from egg yolk, the pharmaceutical industry has focused on soy based lecithin because of its lower risk of disease. For instance, soy lecithin has been used extensively in the intravenous (I.V.) feeding industry. Lecithin is well known to have an anti-spattering effect. The improvement of spattering performance is therefore an important reason for incorporation of lecithin in food compositions.

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