Potassium Metabisulfite As Preservative

Potassium metabisulfite is a white or slightly yellowish crystalline powder. It is a salt of sulfurous acid, made from potassium hydroxide and sulfur dioxide. It is used as a preservative and antioxidant in foods.

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 the color and flavor of foods. It is commonly found in dried fruits, wines, and some processed fruit and vegetable products.

Potassium metabisulfite is permitted for use in food by the FDA. It is generally recognized as safe (GRAS) when used according to good manufacturing practices. Some individuals, particularly those with asthma, may be sensitive to sulfites and experience allergic-type reactions. JECFA has evaluated sulfites and established an acceptable daily intake.