Oils are by nature not miscible with water. If such liquids are combined, this is called an emulsion. Thus, an emulsion refers to a system of two immiscible liquids, one of which is aqueous. Emulsions are milky-turbid liquids. The consistency of individual emulsions can vary from viscous to creamy but strong. We reveal where emulsions are found in everyday life.
What distinguishes emulsions?
One solution is called emulsion when one liquid is in another. Both liquids are not able to mix with each other. One of the two liquids forms droplets. By shaking and stirring, the drops can be evenly distributed and this state obtained by the use of emulsifiers.
There are two types: the water-in-oil emulsion (W / O) and the oil-in-water emulsion (O / W). In the "water-in-oil emulsion", the water is dispersed into tiny droplets surrounded by the fatty component. In the case of the "oil-in-water emulsion", conversely, small fat droplets are enclosed in water.
Emulsifiers as mediators
So that the emulsion does not separate again into its two components, so-called emulsifiers are needed. These are mediators between fat and water, because these substances have a lipophilic and a water-loving (hydrophilic) component. This allows the system to remain stable and prevent flocculation.
Depending on the type and amount of emulsifier used different emulsions are produced, which differ in their consistency from each other. Ideally, the emulsifier is soluble in the outer phase - the liquid that surrounds the drops. As a result, the emulsifier prevents the droplets from growing together and thus stabilizes the emulsion.
Emulsions in food
Everyone is familiar with milk, cream, cream and dressings as emulsions (O / W) from everyday life. Since these emulsions contain no emulsifiers, the oil settles after some time as a layer.
Margarine and mayonnaise are examples of water-in-oil emulsions. Eggs and mustard powder serve as emulsifiers in mayonnaise and keep them viscous.
Emulsions in cosmetic products
From cosmetics, for example, creams and lotions are known as emulsions. Glycerin, used in the creams, prevents their dehydration. Densifying agents make the consistency of cosmetic products smoother. Creams and lotions usually contain additional substances such as amino acids, antioxidants, preservatives and perfume.
Quasiemulsion - what is it?
Quasiemulsions are characterized by the use of fats and waxes. These separate the two liquid phases against each other. With this knowledge you can make ointments yourself. An example is a cooling ointment of yellow wax, peanut oil, water and a greasing thickener called cetyl palmitate. The wax and the thickening agent are so viscous that they prevent the movement of the liquids and thus the fusion of the inner phase.
Natural emulsifiers in everyday life
A natural emulsifier is lecithin. It mainly occurs in eggs, soy and rape. In addition to its function as an emulsifier, lecithin is involved in our metabolism. It transports fatty acids through our blood and through our body cells.
Cholesterol is also a natural emulsifier. On the surface of the skin, it creates a protective layer of sweat. Cholesterol is also part of many endogenous hormones. In butter and margarine, cholesterol also serves as an emulsifier. In milk and cream, the milk protein acts as an emulsifier.
Fatty acids are synthetic emulsifiers. In the food industry, emulsifiers are labeled as E numbers. Emulsifiers are used, inter alia, in the production of the following foods:
- In the production of butter and ice cream emulsifiers lead to more air bubbles. This results in a better spreadability and smoothness.
- Mixed in bread, emulsifiers result in a finer structure, a larger volume and a longer shelf life.
- Chocolate products give emulsifiers the right consistency and prevent white spots on the surface
- In sausage emulsifiers serve to keep the emulsion of protein, fat and water stable and to produce a pleasant consistency.
Detergents contain detergent surfactants - also called detergents. They act in a similar way as emulsifiers. During washing, the surfactants combine with oil and dirt particles and enclose them. The emulsified particles are easily rinsed with the water.
Emulsions and our skin
Emulsions are used as creams to provide our skin with moisture and care ingredients. However, frequent applications of emulsions on the skin may make them dependent on the cream. Then it can happen that the skin ceases its own production of fat or depends on the care substances. Only use creams and lotions if your skin's own fat production is insufficient to cope with external factors or if nutrients are missing.
In addition, you should take care when using dry skin to high-fat W / O emulsions. This ensures adequate supply of the skin with fat and moisture. On very oily skin, however, you should use light O / W emulsions. These do not "grease" your skin, but still provide them with nutrients and care ingredients.
Are emulsifiers harmful?
Artificial emulsifiers are no longer just to make the consistency of food more pleasant, but especially as food additives. These improve the color of the food, achieve a longer shelf life or change the taste.
Many of the artificial emulsifiers - taken in small amounts - are generally safe for our organism. However, there are emulsifiers that cause allergies, have a laxative effect or, when added in large quantities, hinder the uptake of essential trace elements.