亜硫酸ナトリウム

Origin

Sodium sulphite (E221) is an inorganic sodium salt with the formula Na₂SO₃. It is a product of scrubbing sulfur dioxide, a part of the flue gas desulfurization process. It can also be produced by reacting sodium hydroxide with sulfur dioxide. It exists as a white crystalline solid or powder.

Usage

Sodium sulphite is primarily used as a preservative in food and beverages to prevent spoilage and discoloration caused by oxidation. It acts as an antioxidant and antimicrobial agent. Common applications include: * **Food Preservation:** Prevents browning in dried fruits, vegetables, and processed foods. Used in winemaking to inhibit microbial growth and preserve color. * **Industrial Applications:** Used in the paper and pulp industry, textile industry (as a bleaching agent), and water treatment (as an oxygen scavenger). * **Pharmaceuticals:** Used as an antioxidant in some pharmaceutical formulations. The acceptable daily intake (ADI) for sulphites, including sodium sulphite, is up to 0.7 mg per kg of body weight, as established by the Joint FAO/WHO Expert Committee on Food Additives (JECFA).

Side Effects

While generally considered safe at permitted levels, sodium sulphite can cause adverse reactions in sensitive individuals. These reactions are typically due to sulphite sensitivity or allergy. Potential side effects include: * **Allergic Reactions:** Symptoms may include hives, itching, swelling, difficulty breathing, and anaphylaxis (rare but severe). * **Asthma:** Sulphites can trigger asthma attacks in susceptible individuals. * **Gastrointestinal Issues:** Some people may experience nausea, vomiting, or diarrhea. Individuals with sulphite sensitivity should carefully read food labels and avoid products containing sodium sulphite.

Regulatory Status

Sodium sulphite (E221) is approved for use as a food additive in many countries, including those in the European Union, the United States, and Canada. Regulations specify the maximum permitted levels in various food products to ensure consumer safety. In the EU, it is subject to Regulation (EC) No 1333/2008 on food additives. In the United States, it is regulated by the Food and Drug Administration (FDA) under 21 CFR Part 182 as Generally Recognized As Safe (GRAS) when used in accordance with good manufacturing practice.