Sodium Metabisulfite | Lab Alley
About Sodium Metabisulfite
Sodium metabisulfite is an inorganic white powder with a sulfuric odor, which can be dissolved in water to form sodium bisulfite. Like other sulfite compounds, it is an effective antimicrobial, antioxidant, and enzyme inhibitor. Thanks to these properties, it is often used as a preservative and antioxidant, and can be found on food labels under the code E223. It also occurs naturally in fermented products.
Since bisulfite is preferentially oxidized to bisulfate, it acts as an antioxidant in foods, beverages, and cosmetic products. It has the additional advantage of inhibiting enzymatic reactions. Its use in the wine industry dates back many centuries, and is still prevalent today.
Although use of metabisulfite in raw foods is prohibited by the FDA, it may be added to processed foods, including fruits, vegetables, seafood, and alcoholic beverages. It is also frequently employed in the formulation of cosmetic creams, hair colorants, and tanning agents. Sodium metabisulfite may be an excipient in preparations for local anesthesia, to prevent the oxidation of adrenaline.
Major uses and applications
The following areas are the most prevalent applications for sodium metabisulfite.
- Food and wine: Sodium metabisulfite is a valuable preservative since it is naturally occurring, can inhibit enzymatic activity, and will be preferentially oxidized to bisulfate.
- Cosmetics industry: The use of sodium metabisulfite is further extended to the cosmetics industry where it is employed in the formulation of cosmetic creams, hair colorants, and tanning agents.
- Medicines and pharmaceuticals: Sodium metabisulfite may be added to preparations for local anesthesia, to prevent the oxidation of adrenaline.
Common Uses and Applications
- Food/beverage preservative and antioxidant
- Cosmetics preservative
- Bleaching agent
- Disinfectant
- Rubber manufacturing
- Mineral extraction
- Local anesthesia preparations