Lecithin is one of the most used food additives today. Its emulsifying properties aid stability and improve the texture of dressings, sauces, cheeses, chocolates, and dough. It’s also used to create light, stable airs and foams from liquids. What exactly is it, and how is it used?
What is Lecithin?
Lecithin is a generic term applying to any plant or animal derived, yellow-brownish fat which attracts both water and other fats. The word is derived from the Greek, λέκιθος, which means egg yolk (yellow, fatty, animal derived). Other common sources are milk and cream; rape and sunflower seeds; fish roe; and overwhelmingly, soybeans.
What does it actually do?
It acts as an emulsifier, and as such its main uses in cooking are to homogenise liquids.
It acts as a surfactant, so for example, when added to a mixture of air and liquid, it will lower the surface tension of the liquid enabling it to coat the surface of the air bubbles, and retain their structure.
It can help to achieve a smoother texture and to retain moisture. It can also form a barrier between two other surfaces.
Outside the food industry it’s used in paints and printing inks; as a rust inhibitor; in animal feed; in lubricants; and in the pharmaceutical industry.
It’s also used as a dietary supplement to help improve liver function, lower cholesterol, and cure acne.
Lecithin is widely used throughout the food industry. How and why?
• By acting as a surfactant, as described above, it helps retain air within a liquid, as in airs, foams, and espumas created by chefs interested in molecular gastronomy.
• Because it attracts water and acts as a stabiliser it is used by bakers to extend the shelf life of bread, pastries and cakes, preventing them from becoming stale too quickly.
• It also stabilises fermentation caused by the yeast or other rising agent and retains the gas produced during the process thereby increasing the volume.
• By acting as an emulsifier and breaking oil in food down into smaller particles it helps to create a smoother texture, especially in doughs. It’s the lecithin in egg yolks that emulsifies mayonnaise or hollandaise.
• It is often added to chocolate to prevent the sugar from crystallising and the cocoa fats from separating.
• Because it acts as an emulsifier it helps to stabilise margarine and prevent it from spattering when used for frying.
• As a surfactant, or coating, it’s often added to non-stick cooking sprays. It also stops sweets from sticking to the sweet papers.