lecithin

Lecithin is a generic term for a family of phospholipids that are essential components of cell membranes and are used commercially as emulsifiers. They are amphiphilic molecules with hydrophobic fatty acid tails and a hydrophilic phosphate-containing head, enabling them to stabilize mixtures of oil and water.

Commercial lecithin commonly contains phosphatidylcholine as its major phospholipid, with significant amounts of phosphatidylethanolamine, phosphatidylinositol, and phosphatidylserine. The exact composition varies by source, processing, and refinements. Lecithins also contain small amounts of triglycerides, sterols, and other lipids.

Lecithin is extracted from both animal and plant sources, most notably egg yolk and soybeans, but also sunflowers, corn, and canola. It is produced by solvent extraction or mechanical pressing, followed by purification and deodorization to yield liquid, granulated, or powdered products used as food additives or supplements.

In foods, lecithin functions as an emulsifier and stabilizer, improving texture and preventing separation in products such as baked goods, chocolate, ice cream, and dressings. It is also used as a release agent and as a carrier for liposomal drug formulations; in cosmetics, it acts as a moisturizer and surfactant, and as a choline source in supplements.

Lecithin is generally recognized as safe in regulated amounts; soy- or egg-derived lecithin can pose allergy risks for sensitive individuals. Regulation and labeling vary by country, and products may be sold as "lecithin," "phospholipids," or "phosphatidylcholine-rich lecithin." Storage is typically cool and dry.