Food emulsifiers are chemical substances that help food ingredients, such as water and oil, to blend when mixing, forming an emulsion. Emulsifiers are also used as aerating agents to make desserts such as mousses and cakes -- and as crystallisation inhibitors, to avoid the formation of white patches on chocolates. Common emulsifiers include lecithin, mono and diglycerides, glycerides, monoglyceride derivatives, and fatty acid derivatives.

Extracted from vegetable oils such as soy and sunflower oil, lecithin has been used as a food emulsifiers since the 1930s. The number 184.1400 identities lecithin on the labels of food products in the United States. In Canada, lecithin is the equivalent of L.2 and in European products, E 322. Lecithin is used in a wide range of food products, including margarine, chocolate, breads and cakes, bubble gum, salad dressings and sauces.

Mono and diglycerides, as well as their purified form distilled monoglycerides, are the oldest and most common food emulsifiers. These emulsifiers are produced by mixing edible oils with glycerin, and widely used in bakery and dairy products, and margarine. On the label of food products, mono and diglycerides correspond to the number 182.4505 in the U.S., while in Canada it's M.4 and M.5. In Europe, the number E 471 identify these emulsifiers.

The combination of monoglycerides with other substances produces emulsifiers with specialized function called monoglyceride derivatives. For instance, ethoxylated monoglycerides are the result of the interaction between a monoglyceride and ethylene oxide. Other monoglyceride derivatives include acetoglycerides (172.828) and diacetyl tartaric esters of monoglycerides or DATEM (184.1101). They are common cake emulsifiers, because they increase the aeration of the dough.

Polyglycerol esters (PGE), propylene glycol esters (PGMS), stearoyl lactylates, sucrose esters, sorbitan esters and polysorbates are the most common food emulsifiers derived from fatty acids. PGE are used in cakes and icings, margarine and salad oils, while PGMS main application is whippable toppings. Stearoyl lactylates are used as dough strengtheners and conditioners in breads, while sorbitan and polysorbates are used for aeration in cakes and icings. Sucrose esters are also used in bubble gum, sauces, soups and canned liquid coffee.