Food Ingredient

Sources and Categories

Lecithin is a complex mixture of phosphatides, primarily phosphatidylcholine (PC), phosphatidylethanolamine, phosphatidylserine, and phosphatidylinositol, with varying amounts of triglycerides, fatty acids, and carbohydrates. It is isolated from animal or vegetable sources, with main sources being maize, egg yolk, and soybean.

Chemical Composition and Structure

Lecithin is composed of phosphatides, predominantly phosphatidylcholine, along with other phospholipids, triglycerides, fatty acids, and carbohydrates. Its molecular structure is amphiphilic, allowing it to exhibit excellent emulsifying properties.

Mechanism of Action

Lecithin acts as an emulsifier, modifying crystal habit (size), and interacts with wax molecules to alter the morphology and dimensions of fat crystals. It also self-assembles through non-covalent interactions, such as hydrogen bonding, in food products.
Lecithin exhibits excellent emulsifying properties due to its amphiphilic molecular structure. It's main component, phosphatidylcholine, plays a crucial role in cell membrane formation and serves as a regulatory molecule in various biological processes.
Lecithin is metabolized to choline, which can generate the neurotransmitter acetylcholine, promoting cell activation and neural network flexibility.

Medical Applications

Lecithin has been reported to improve cardiovascular health by preventing cholesterol deposition, enhance immune and liver functions, and improve skin texture. Choline derived from lecithin hydrolysis can promote cell activation and neural network flexibility.

Industrial Applications

Used as an emulsifier in food products like margarine, chocolate, cakes, and breads, and in personal care products. Also utilized in livestock and poultry feed industry to enhance production performance, nutrient digestibility, and health status. Lecithin nanoparticles coated with chitosan serve as nanocarriers for bioactive compounds, improving their stability, release, and effectiveness.

Production Methods

Commercial lecithin is isolated through hydration of solvent-extracted oils from sources like soy, safflower, or corn. It can be further processed by hydrogenation or enzymatic modification. Industrial production involves bleaching, if desired, by hydrogen peroxide and benzoyl peroxide, and drying by heating. Enzyme-modified lecithin, such as lysolecithin, is prepared by treating lecithin with phospholipase A2 or pancreatin.

Definition

ChEBI: A glycerophosphocholine compound having O-acyl substituents at both the 1- and 2-positions of the glycerol. It is a major constituent of cell membranes.

Biochem/physiol Actions

It also acts as a source of lipid messengers/ bioactive lipids including: lysophosphatidylcholine, diacylglycerol, phosphatidic acid, lysophosphatidylcholine, arachidonic acid and platelet activating factor. Phosphatidylcholine is produced in the liver by the CDP-choline (cytidine diphosphocholine) pathway.

Safety

Lecithin is a component of cell membranes and is therefore consumed as a normal part of the diet. Although excessive consumption may be harmful, it is highly biocompatible and oral doses of up to 80 g daily have been used therapeutically in the treatment of tardive dyskinesia. When used in topical formulations, lecithin is generally regarded as a nonirritant and nonsensitizing material. The Cosmetic Ingredients Review Expert Panel (CIR) has reviewed lecithin and issued a tentative report revising the safe concentration of the material from 1.95% to 15.0% in rinse-off and leave-in products. They note, however, that there are insufficient data to rule on products that are likely to be inhaled.

Incompatibilities

Incompatible with esterases owing to hydrolysis.

Who Evaluation

Evaluation year: 1980