sulfited

Sulfited is an adjective used to describe substances that have been treated with sulfites or that contain sulfite residues. The sulfite ion, SO3^2−, derives from sulfurous acid and forms salts such as sodium sulfite (Na2SO3), sodium bisulfite (NaHSO3), and sodium metabisulfite (Na2S2O5). In solution, sulfites can release sulfur dioxide (SO2) under acidic conditions, which contributes to their preservative and antioxidant effects.

In food and beverage production, sulfites are used to preserve color, slow browning, and inhibit microbial growth. Sulfited ingredients and products include dried fruits, wines, fruit juices, syrups, pickles, and some canned or processed vegetables. The label sulfited or contains sulfites is commonly found on products where sulfites have been added above certain regulatory thresholds.

Chemically, sulfites can react with aldehydes to form bisulfite adducts, a reaction that helps protect delicate aromas and flavors in foods. Under acidic conditions, the bound SO2 can be released, providing a preservative effect. In industrial contexts, sulfites are also used in paper, textile, and photography processes, though food and beverage uses are the most widely known.

Safety and regulation around sulfited products vary by jurisdiction. Some individuals are sensitive to sulfites and can experience adverse reactions, particularly among asthmatic people. Many regions require labeling of foods and beverages that contain added sulfites above a specified threshold, commonly around 10 mg per kilogram or liter, to inform sensitive consumers.