e220 Sulphur Dioxide

Food additive in the category of natural preservatives, used since ancient times in the Roman Empire and ancient Egypt. It is a colorless gas, obtained by burning sulphur. This gas dissolves in the aqueous phase of the food subject to preservation and forms the reactive agent, provided that the food has an acidic pH (lower than 7). Thus enzymatic and bacterial degradation is prevented. Being oxidizing, it is also used as a bleaching agent for flour, but usually it modifies (oxidizes) the natural color of foods and reduces the quantity of vitamins in these. By heating the food, the additive is eliminated as a gas. When ingested, it is broken down in the liver into harmless sulphates and is excreted by urine.