E220 - Sulfur Dioxide

Characteristics of the additive E 220 / sulfur dioxide

Sulfur dioxide (additive E 220) belongs to the group of preservatives. It is an antioxidant, whitens and stabilizes the colors of food and beverages. Sulfur dioxide is a colorless non-flammable gas with a sharp and suffocating odor. The density of this gas is more than 2 times higher than that of air, but at a temperature of -10 ° C it is able to condense into a liquid. Its chemical formula is SO2 .

E 220 has a natural source, but for industry it is obtained chemically by burning organic compounds containing sulfur (eg hydrogen sulfide) or firing sulfide ores (pyrite). Under laboratory conditions, sulfur oxide is obtained by reacting hydrosulfites and sulfites with strong acids. During the reaction, sulfuric acid is formed, which is immediately decomposed into sulfur dioxide and water.

Additive E 220 is dissolved in water. Unstable sulfuric acid is formed during the reaction. Sulfur dioxide is soluble in sulfuric acid and ethanol. SO2 is rapidly oxidized in the body, so it is easily excreted in the urine. The permissible daily dose of the preservative is less than 0.7 mg per kilogram of body weight.

Use of sulfur dioxide

The additive is widely used to protect vegetables and fruits from premature darkening and rot. In shops and warehouses, vegetables and virtually all types of citrus fruits are treated with sulfur dioxide so that they can be transported over long distances. The additive E 220 is also used in the industrial production of dried fruits, as it preserves their color and appearance and prevents rot.

Sulfur dioxide is a major component in winemaking. The additive E 220 is used as an antibiotic and antioxidant, protecting the wine from oxidation and spoilage caused by bacteria. The antimicrobial effect of the supplement also helps to minimize the formation of volatile acids. The addition of the preservative in the winemaking process contributes to the binding of acetaldehyde, which directly stabilizes the color, helps to obtain the necessary oxidizing and reducing potential, and this leads to greater resistance of the wine at the microbiological level.

Sulfur dioxide is found in all types of wine. The inscription on the label "contains sulphites" also indicates that the wine has been treated with sulfur oxide. In the alcoholic beverage of fermented grape juice, sulfur dioxide exists in free and bound form or in combination. The maximum permitted amount of the additive E 220 in the wine must be up to 350 ppm. This value depends on the type of wine and the country in which it is sold. For example, in the EU this rate is 160 ppm for red wines and 210 ppm for white and rosé wines.

The additive is also used in the production of beer, soft drinks, dried fruits, vinegar and potato products.

Impact on humans

E 220 refers to unhealthy food additives because it is very toxic. Sulfur dioxide is able to cause various allergic reactions and metabolic problems in people with reduced kidney function. Some people should avoid taking the supplement, especially asthmatics. In addition, sulfur dioxide has the ability to destroy thiamine (vitamin B1), but well protects vitamin C from oxidative cleavage.

Inhalation of sulfur dioxide causes coughing, runny nose and suffocation. Prolonged contact with the supplement may lead to vomiting, speech becomes difficult to understand (incoherent) and acute pulmonary edema may occur.