Lecithin is a natural product also called alpha-phosphatidylcholine that is very complex in that it is composed of choline, fatty acids, glycerol, phospholipids and amphiphilic lipids. Phospholipids are the main constituent and can be extracted from both vegetable fats and eggs. The function of phospholipids, which are found in animal and plant cell membranes, is the proper maintenance of vital organs in the human body: liver, brain, etc.

Lecithin is a natural phospholipid found in many foods, such as soy, eggs, sunflower seeds, and other seeds. It is primarily used as an emulsifier and moisturizing agent in cosmetic, food, and pharmaceutical formulations. Due to its ability to stabilize oil and water mixtures, lecithin is a key ingredient in creams, lotions, and processed foods, where it helps improve texture and product longevity.

Chemical Composition and Structure

Lecithin is composed of a mixture of phospholipids, with the main components being phosphatidylcholine, phosphatidylethanolamine, and phosphatidylinositol. Its molecular structure is amphiphilic, meaning it has a hydrophilic (water-loving) head and a lipophilic (fat-loving) tail, making it ideal for binding oils and water together. This characteristic makes it one of the most commonly used natural emulsifiers in cosmetic and food industries.

It is possible that lecithin is derived from animal sources. There are different methods of producing lecithin: from soya hexane extract, by hydration of soya with corn oil or solvent. The fatty acids used to make lecithin include palmitic acid, oleic acid and stearic acid.

Production Process

Lecithin is primarily extracted from soybean or sunflower oil through a degumming process, where vegetable oils are separated from the phospholipids. The crude lecithin is then purified and decolorized to obtain the final product. This process is highly controlled to ensure a high level of purity and optimal performance across different applications. 

• Extraction: Lecithin is primarily extracted from plant sources such as soybean, sunflower, or rapeseed. The seeds are cleaned and crushed to facilitate the extraction of oils containing lecithin.

• Refining of Oils: The oils extracted from the seeds are refined to remove impurities, free fatty acids, and other undesirable substances. This process may include neutralization, bleaching, and deodorization stages.

• Separation of Lecithin: Once refined, the oils can be treated with a solvent, such as ethanol, to separate lecithin from other lipid components. Lecithin dissolves in the solvent, while other fats and impurities remain separated.

• Evaporation of Solvent: The solution containing lecithin is then subjected to an evaporation process to remove the solvent, resulting in a concentrated lecithin extract.

• Quality Control and Packaging: Finally, lecithin undergoes quality control checks to verify its purity and functional properties. After analysis, it is packaged for distribution and use in food and cosmetic products.

Physical Properties

Lecithin appears as a granular powder or a viscous liquid, with a color ranging from light yellow to brown, depending on the source from which it is extracted (soy, sunflower, eggs). It is soluble in fats and partially soluble in water, making it an excellent stabilizer in water-in-oil (W/O) or oil-in-water (O/W) emulsions. 

Applications

• Cosmetic Industry: Used in creams, lotions, hair conditioners, and skincare products for its emollient and moisturizing properties. It helps improve product texture and stabilize emulsions.

• Food Industry: Employed as an emulsifier in products such as margarines, chocolates, baked goods, and processed foods to improve texture and shelf stability.

• Pharmaceutical: Used in pharmaceutical formulations as an excipient, helping improve the bioavailability of certain drugs and stabilizing formulations.

Food

The food industry uses soya lecithin and sunflower lecithin (E322) as lubricants, antioxidants and for their ability to protect and preserve the fragrance of ingredients.

Medical

In medical terms, the application of lecithin as an antiviral nasal spray (1) and for the treatment of allergic rhinitis has been studied. Furthermore, lecithin liposomes have proven effective for ENT disorders (2).

Cosmetics

Skin conditioning agent - Miscellaneous.  This ingredient has the task of modifying the condition of the skin when it is damaged or dry by reducing its flakiness and restoring its elasticity.

Surfactant - Emulsifying agent. Emulsions are thermodynamically unstable. Emulsifiers have the property to reduce the oil/water or water/oil interfacial tension, improve emulsion stability and also directly influence the stability, sensory properties and surface tension of sunscreens by modulating their filmometric performance.

In cosmetic products, lecithin, also in hydrogenated, biodegradable form, performs the dual function of conditioning agent and amphoteric surfactant (removes dirt particles) emulsifier. Minor functions such as antioxidant and dispersing agent.

Safety in Use
Lecithin is generally considered safe for use in food, cosmetic, and pharmaceutical products. It is a natural ingredient well tolerated by the skin and the human body, even for individuals with sensitive skin or allergies. In the food industry, it is considered safe for human consumption.

Allergic Reactions
Allergic reactions to lecithin are rare but can occur in people with specific allergies to lecithin sources, such as soy or eggs. However, sunflower-derived lecithin is often used as a safe alternative for those with soy allergies.

Toxicity and Carcinogenicity
 It has been widely used in the food and cosmetic industries for decades without significant negative health effects.

Environmental Considerations
Lecithin is biodegradable and derived from renewable sources, such as soy and sunflower, making it an eco-friendly ingredient. However, the use of soy-derived lecithin may raise environmental concerns related to the intensive cultivation of soy, especially if it is genetically modified (GMO). Sunflower lecithin is often preferred in organic and non-GMO products.

Regulatory Status
Lecithin is approved as a food additive and cosmetic ingredient by major regulatory authorities, including the European Union and the Food and Drug Administration (FDA) in the United States. In the food industry, it is commonly classified as E322.

The most relevant studies on the subject have been selected with a summary of their contents:

Lecithin studies

CAS   8002-43-5    8030-76-0   8002-43-5    93685-90-6

References___________________________________________________________________

(1) Qaisrani MN, Belousov R, Rehman JU, Goliaei EM, Girotto I, Franklin-Mergarejo R, Güell O, Hassanali A, Roldán É. Phospholipids dock SARS-CoV-2 spike protein via hydrophobic interactions: a minimal in-silico study of lecithin nasal spray therapy. Eur Phys J E Soft Matter. 2021 Oct 30;44(11):132. doi: 10.1140/epje/s10189-021-00137-3.

(2) Hofauer B, Bas M, Strassen U, Matsuba Y, Mansour N, Knopf A. Sinunasale Symptome ANCA-assoziierter Vaskulitiden und deren Therapie mit Liposomen Liposomal local therapy of sinunasal symptoms in ANCA associated vasculitis. Laryngorhinootologie. 2014 Jul;93(7):461-6. German. doi: 10.1055/s-0034-1372588.