Why do delicious foods need emulsifiers?

In daily production, the production of those pleasing to the eye, the smell of food, food emulsifiers and other additives are indispensable. According to statistics, the total annual consumption of food emulsifiers in the world has exceeded 350,000 tons. It can be seen that delicious food cannot be separated from emulsifiers.
What is an emulsifier
Emulsification is the process of evenly distributing oil (or other fats) into water, and an emulsifier is a surfactant that can turn two liquids that are insoluble into an oil-in-water emulsion or an oil-in-water emulsion. As a food additive, in addition to emulsifying in food processing, emulsifier also plays the role of breaking milk, helping to dissolve, dispersing, wetting, foaming and suspension, which contributes greatly to food color, aroma and taste.
Oil and water are not miscible because at the interface of oil and water, the water and oil molecules have a tendency to “escape” each other and return to the interior of their respective molecular bases. As a direct result of this tendency, the separate interface between oil and water is reduced. From the point of view of energy, there is a higher energy at the interface of oil and water than pure water or pure oil, which is called the interface energy. When the oil is dispersed into the water, the surface area is greatly increased, and the surface energy of the entire system is increased. Since the movement of nature is always in the direction of high to low total energy, the dispersed oil droplets will reassemble, thereby reducing the surface energy of the entire system.
However, the molecule of emulsifier is generally composed of polar and non-polar groups in chemical structure, and the polar group is easily soluble in water and has hydrophilic properties, so it is called hydrophilic group; Non-polar groups are easily soluble in oil, so they are called oleophilic groups. These two groups are like the two “hands” of the emulsifier: the “hand” of the hydrophilic group is dissolved with water; The hand of the oleophilic group is inseparable from oil. Due to the existence of emulsifier, through mechanical agitation, the two liquids that are not soluble in oil and water form a new system – emulsion. An emulsifier is a surfactant whose main function is to reduce interfacial tension.
Why should emulsifiers be added to food
Many foods contain water and oil (i.e., fat), such as cakes, ice cream, coffee partners, protein drinks, and ham sausages. However, we all know a common sense: water and oil do not dissolve, so when making egg soup, the oil flower always floats on the surface of the soup.
If a bowl of egg soup, oil flower floating, does not affect eating, you may also feel this bowl of egg soup color, aroma, taste, looks comfortable. However, if a cake is prepared, put on the shelf, and soon there is oil oozing everywhere, you will not buy such a cake; If an ice cream has clumps of cream in it, you will find it difficult to swallow. These phenomena are caused by the insolubility of oil and water, and emulsifiers are needed to solve the problem of oil and water solubility.
Emulsification is the process of evenly distributing oil (fat) into water. If you pour oil in water, there is water below and oil above, such a drink can not be drunk. But if the emulsifier is used to evenly disperse the oil and form a cup of milky liquid, whether it is appearance or taste, it has the desire to let people drink it. Many other foods, such as cakes, ice cream, etc., must be evenly dispersed in order to obtain a delicate taste.
After the emulsifier is added to the food, it can make the non-soluble oil and water in the food to form a stable emulsion or emulsion system of substances. It can improve the surface tension between two phases in the system, and form a uniform, dispersed and unified system. The use of food emulsifiers is not a long history, from the 1920s Americans added lecithin to bread began, has now formed fatty acid polyol ester and its derivatives and natural emulsifier soy lecithin based food emulsifier system.
With the progress of science, emulsifiers are more and more showing their unique talents. Food emulsifiers can be used in ice cream, margarine, butter, chocolate, but also in bread, noodles, tofu, pastries, biscuits, confectionery, dairy, fish and meat products, convenience foods, jams. Its role is to make pastry crisp, bread soft, tofu delicate, candy does not stick to the teeth, jam does not water, and so on, but also to stabilize food properties, improve the role of food flavor, and can improve the taste of food, extend the storage time of food.
At present, there are not many substances approved to be used as food emulsifiers, most of which are esterified products of some fatty acids. For these substances, it is also “mature one, approved one”, and only after a large number of safety tests can they be used in food. At present, there are about 60 kinds of emulsifiers allowed in the world, 58 kinds in the United States, and more than 30 kinds of emulsifiers allowed in China.
It is worth mentioning that protein also has an emulsifying effect, coupled with its own nutrition, so the use of protein as emulsifier is more and more attention. However, protein emulsification efficiency is low, but the price is much more expensive. One of the most commonly used emulsifiers in food is soy lecithin. It is a by-product of soybean deep processing and has been widely used in food production.