Lecithin

Products

Lecithin is available in specialty stores. It is found in many pharmaceuticals as an excipient, as well as an additive in foods, and is available as a dietary supplement.

Structure and properties

Lecithins exist as brown granules or viscous liquids and have amphiphilic properties, meaning they have both hydrophilic and lipophilic structural components. They are mixtures or fractions of phospholipids such as phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine and phosphatidylinositol. Lecithin was originally isolated from egg yolk and is now usually derived from the oil of soybeans (soy lecithin). Lecithins can therefore be of animal or plant origin. Other possible sources include cottonseed, corn, sunflower seed and rapeseed. It can also be obtained from bovine brain, but this plays little role in practice. Phospholipids consist of a diglyceride, a phosphate group and an alcohol, such as choline or serine, which are esterified together. Other components such as triglycerides, steroids or carbohydrates are also present. Lecithins can be partially hydrolyzed with the help of enzymes and are present accordingly.

Effects

Lecithins have emulsifying, homogenizing, stabilizing, hydrating, and texture-improving properties. They combine an aqueous phase and a fatty phase to form an emulsion.

Areas of application

  • As a pharmaceutical excipient, as an emulsifier for the preparation of emulsions.
  • As a dietary supplement for the substitution of choline.
  • As a tonic.
  • Lecithins play a prominent role in the production of processed foods, for example, pastries, bread, chocolate and margarine. Bread gains volume through the addition of lecithin, among other things.