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Sulfite

physical science Maturity 11-13 Next article →

Sulfites are special parts of chemicals found in many things.

Sulfite-ion-3D-vdW
Sulfite-ion-3D-vdW

They occur naturally in some foods and even inside the human body. People also add them to food and drink on purpose. These added sulfites act as preservatives to help food stay fresh. They can stop things from spoiling or changing too much.

Sulfite-ion-2D-dimensions
Sulfite-ion-2D-dimensions

You might find them in dried fruits or dried potato products. They are also used to make certain caramel colors for food.

To understand how they work, we can look at their shape.

Sulfite-resonance-2D
Sulfite-resonance-2D

The sulfite ion has one sulfur atom and three oxygen atoms. One oxygen is held by a double bond. The other two oxygens are held by single bonds. This creates a shape called a trigonal pyramid. It looks a bit like a tiny three-sided pyramid. This shape is similar to a molecule called ammonia. This structure helps them work well as they move through food.

Rules about sulfites have changed over many years. In 1986, the U.S. Food and Drug Administration made a big change. They banned adding sulfites to fresh fruits and vegetables eaten raw. This happened because sulfites can destroy vitamin B1 in some foods. In the United States, wine labels must show sulfites if they have more than 10 parts per million. The European Union started a similar rule in November 2005. In 2012, the EU made even newer rules for organic wines.

There are many different types of sulfites used today. Some common ones include sodium sulfite and potassium metabisulfite. You might also see sulfur dioxide, which is a related chemical. In Europe, these are often given special codes called E numbers. For example, sulfur dioxide is E220 and sodium sulfite is E221. These names help workers know exactly which one is being used. Different countries have different lists of which sulfites are allowed in food.

Most people can eat sulfites without any trouble at all. However, some people are very sensitive to them. For these people, sulfites can cause sneezing or a swollen throat. It can even cause skin problems for those using certain cosmetics.

Co(ethylenediamine)2(SO3)N3-3D-balls
Co(ethylenediamine)2(SO3)N3-3D-balls

A very rare sickness makes it hard for some babies to break down sulfite. This can cause damage to the brain if it is not treated. Since 2009, doctors have used a medicine called fosdenopterin to help. This shows how important it is to understand these tiny chemicals.

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🖼️ Images & Media (5)
File:Sulfite-ion-3D-vdW.png
Sulfite-ion-3D-vdW.png
File:Sulfite-ion-2D-dimensions.png
Sulfite-ion-2D-dimensions.png
File:Co(ethylenediamine)2(SO3)N3-3D-balls.png
Co(ethylenediamine)2(SO3)N3-3D-balls.png
File:Sulfite-resonance-2D.png
Sulfite-resonance-2D.png
File:Bisulfite-equilibrium-2D.png
Bisulfite-equilibrium-2D.png
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