E228 - Potassium bisulphite

Origin

Potassium bisulphite (E228) is an inorganic salt formed by the reaction of potassium hydroxide with sulfur dioxide. It is a sulfite, meaning it contains the sulfite ion (SO32-). It is typically produced by bubbling sulfur dioxide gas through a solution of potassium hydroxide until the desired concentration is achieved. The resulting solution is then crystallized to obtain the solid potassium bisulphite.

Usage

Potassium bisulphite is primarily used as a preservative and antioxidant in the food and beverage industry. It inhibits the growth of microorganisms, preventing spoilage and extending the shelf life of various products. It is particularly effective against bacteria, yeasts, and molds. It is commonly used in the production of wine, beer, fruit juices, dried fruits, and pickled vegetables. In winemaking, it prevents oxidation and microbial growth, contributing to the stability and clarity of the wine. It is also used to bleach food products. The levels of use are regulated to ensure safety and effectiveness.

Side Effects

Sulfites, including potassium bisulphite, can cause allergic reactions in sensitive individuals. Symptoms can range from mild skin rashes and hives to severe asthma attacks and anaphylaxis. Individuals with asthma are particularly susceptible to sulfite sensitivity. Regulatory agencies require that foods containing sulfites above a certain concentration (typically 10 ppm) be labeled to inform consumers. The Joint FAO/WHO Expert Committee on Food Additives (JECFA) has established an Acceptable Daily Intake (ADI) for sulfites, which should be considered when determining safe levels of potassium bisulphite in food products. It is important to note that the ADI applies to the total intake of all sulfites from all sources, not just potassium bisulphite. Some studies suggest that long-term exposure to high levels of sulfites may have other adverse health effects, but more research is needed in this area.