E223 – Sodium Metabisulphite

Description

White or yellow crystalline powder with a pungent, sulphurous odour

Risks

Notes

Sodium metabisulfite is a white or yellowish crystalline powder that's created when sodium carbonate (washing soda) reacts with sulfur dioxide gas. You might notice its distinctive sharp, sulfurous smell - similar to struck matches. This chemical compound is manufactured industrially and belongs to a family of sulfite preservatives that release sulfur dioxide when dissolved in water. This additive works as a powerful preservative and antioxidant, preventing food from spoiling and stopping fruits and vegetables from turning brown when exposed to air. You'll commonly find sodium metabisulfite in dried fruits (especially apricots and raisins), wine, fruit juices, pickled vegetables, and some processed potato products like chips and frozen fries. It's particularly effective at preventing bacterial growth and maintaining the fresh appearance of foods. Sodium metabisulfite is synthetically produced and suitable for vegetarian and vegan diets. However, it's important to know that sulfites can trigger severe allergic reactions in some people, particularly those with asthma - which is why foods containing sulfites must be clearly labeled in many countries. It's also worth noting that sulfites can destroy thiamine (vitamin B1), so they're not permitted in foods that are significant sources of this vitamin.