sulfiti

Sulfites are a group of chemical compounds that contain the sulfite ion, SO3^2-. They are the salts and esters of sulfurous acid. Sulfites can be formed by the reaction of sulfur dioxide with bases. In nature, sulfites are found in volcanic gases and in small amounts in some minerals.

Commercially, sulfites are used as preservatives in food and beverages, primarily because of their antioxidant and antimicrobial properties. They help prevent spoilage by inhibiting the growth of bacteria, yeasts, and molds, and by preventing the oxidation of certain food components. Common food products that may contain sulfites include dried fruits, wines, juices, processed meats, and some baked goods. Sulfites are often listed on ingredient labels as sulfur dioxide or by their E number, such as E220 for sulfur dioxide, E221 for sodium sulfite, and E224 for potassium metabisulfite.

The use of sulfites can cause adverse reactions in some individuals, particularly those with asthma. Symptoms can range from mild, such as hives or itching, to severe, including respiratory distress and anaphylaxis. For this reason, foods containing sulfites above a certain concentration are required to be labeled in many countries. Sulfites are also used in other industrial applications, such as in photography and as bleaching agents.