Potassium Metabisulfite

Potassium metabisulfite is a white or slightly yellowish crystalline powder. It is a salt of sulfurous acid, produced by reacting potassium hydroxide with sulfur dioxide. It is commonly used as a preservative and antioxidant in foods and beverages.

Manufacturers add potassium metabisulfite to foods to prevent spoilage by inhibiting the growth of bacteria, yeasts, and molds. It also acts as an antioxidant, preventing browning and preserving color in fruits and vegetables. It is frequently found in dried fruits, wines, fruit juices, and processed potatoes.

Potassium metabisulfite is generally recognized as safe (GRAS) by the FDA for use as a food additive. It is a sulfite, and some individuals, particularly those with asthma, may be sensitive to sulfites, experiencing allergic-type reactions. The Joint FAO/WHO Expert Committee on Food Additives (JECFA) has evaluated sulfites and established acceptable daily intakes. However, the FDA has also noted that sensitive individuals may react to sulfites.