If oil is poured into water, the two liquids do not mix. At least, as long as you do not add an emulsifier. Emulsifiers are molecules that have an end having an affinity for water (hydrophilic) and an end having an affinity for oil (hydrophobic). Thanks to them, the water and the oil can be finely dispersed into one another to create a stable, homogeneous and fluid emulsion.
Ancient Greeks used the emulsifying power of beeswax in cosmetics and egg yolks were probably the first emulsifier used in “food production” in the early 19th century. Due to the relatively short stability of the egg yolk, the manufacturers then used soy lecithin, which has been an important food emulsifiers product since the 1920s. But the most significant innovation in this field took place ten years later. late with the marketing of certain fatty acid derivatives (mono and di glycerides). In 1936, their use was patented for the production of ice creams. Today, emulsifying food additives play an important role in making products such as margarine, mayonnaise, creamy sauces, sweets, many processed and packaged foods, confectionery and a variety of baked goods.
Some common applications of emulsifiers
It is possible to make bread bakery ingredients without emulsifier, but the result is often dry, low volume and quickly stale. By adding only 0.5% emulsifier to the dough, the bread volume increases, the structure of its crumb is lighter and it keeps longer. Two types of emulsifiers are used for bread making: emulsifiers for firming dough (eg acetyl – tartaric esters (E 472) and sodium or calcium stearyl – 2 – lactylate (E 481, E 482)) and those intended to make it more flexible (eg mono and di glycerides of fatty acids (E 471)). The agents for firming the dough make it possible to improve the texture and the volume of the bread. The agents intended to soften the dough make it possible to obtain a softer crumb structure and to extend the shelf life.
All chocolates contain 0.5% lecithin (E 322) or ammonium phosphatides (E 442). These emulsifiers are added to give the chocolate the desired consistency, in order to be able to give it the shape of plates, bars, etc. If the chocolate has been stored at too high temperatures, its surface may appear dull or bleached. It is said that chocolate has “bloomed”, which makes it less attractive to the consumer. Sorbitan tri-stearate (E 492) can delay this phenomenon.
Ice cream is one of the most complex food products. Both foam and emulsion, it contains ice crystals and an unfrozen aqueous mixture natural ingredients. Emulsifiers are added during the freezing process to promote a smoother texture and slow the melting of the ice cream once served. They also improve freeze-thaw stability. Mono and di glycerides of fatty acids (E 471), lecithin (E 322) and polysorbates (E 432 to E 436) are commonly used in the production of ice cream. Other desserts, such as sorbets, milkshakes, frozen mousses and frozen yogurt are also involved.