Soya lecithin is a fatty substance that occurs naturally in eggs, whole grains and legumes (which include soybeans, peas and alfalfa). Lecithin was first isolated by Maurice Gobley in 1850 from egg yolk and named after it (Greek ‘lekithos,’meaning ‘yolk of egg’).
It is a vital, structural, cell membrane component of living organisms, and it is produced naturally in the body.
Most commercial lecithin now comes from soya bean, from which it was obtained in the 1930s.
In nutrition, egg was long a mystery to researchers because it is very high in cholesterol, but eating them in moderation didn't seem to significantly increase cholesterol blood levels. This was until lecithin in the egg was found to help prevent cholesterol from attaching itself to the walls of blood vessels. There are many health claims about lecithin as a supplement - from helping against neurological conditions to improving liver function.
Maurice Gobley identified it as the substance that allows oil and water to mix - which makes lecithin unusual in that it's a naturally occurring surfactant (surface-active agent).
Surfactants, also known as tensides or wetting agents, are substances used to lower the surface tension of a liquid, which then allows easier spreading of product and helps to emulsify it (blend two ingredients that would otherwise separate, such as water and oil). For this reason, lecithin is a highly valuable ingredient in cosmetics and is also widely used in the food industry to help improve the texture of baked goods, sauces and processed foods, such as margarine and chocolate.
When applied in a cosmetic product, lecithin also softens the skin and helps the absorption of other ingredients.
Adding a natural surfactant to the formula also reduces the need for synthetic ingredients and allows for more sophisticated blends of raw materials.