Sulfiittisuolat

Sulfiittisuolat are inorganic salts that contain the sulfite anion (SO3^2-). They are derived from sulfurous acid, H2SO3, which is formed when sulfur dioxide gas dissolves in water. Sulfites are generally soluble in water, with notable exceptions like calcium sulfite and lead sulfite. They can act as reducing agents due to the sulfur atom's oxidation state.

Many sulfites occur naturally as minerals, though they are less common than sulfates. Industrially, sulfites are produced by reacting sulfur dioxide with bases or alkali metal carbonates. Sodium sulfite (Na2SO3) is a widely used sulfite, employed as a preservative in food and wine to prevent oxidation and spoilage. It's also used in photography and as a reducing agent in various chemical processes. Potassium sulfite (K2SO3) and ammonium sulfite ((NH4)2SO3) are also known.

In the food industry, sulfites are designated by numbers such as E221 for sodium sulfite, E222 for sodium bisulfite, and E223 for sodium metabisulfite. They are often added to dried fruits, processed potatoes, and some beverages. While effective preservatives, sulfites can trigger allergic reactions in sensitive individuals, particularly those with asthma, leading to symptoms like wheezing, hives, and gastrointestinal distress. This has led to regulations requiring the labeling of foods containing sulfites. In winemaking, sulfites are used to inhibit bacterial growth and prevent oxidation, contributing to the wine's stability and shelf life.