Why is sulfur dioxide needed?

Answer 1

In food and drink production Sulphur is used as an anti oxidant. It is commonly used in wine and cider production, as well as in the apple juice industry. You will also find it is used a lot in the dried fruit industry.

Sulphur dioxide prevents oxidation which is the effect of oxygen on a product. In the case of dried fruits it prevents them from going brown.

A good example is dried apricots. These are only bright orange if they have been treated with Sulphur otherwise they go a brown colour when dried.

With dried fruits the effect is mostly visual - a brown apricot tastes pretty much the same as a orange one, but in the case of liquids such as apple juice and wine, the use of Sulphur has a more preservation effect and keeps the product tasting fresh.

Oxidisation in a juice, wine or cider would be considered a fault and is undesirable as it makes the product taste coppery - think of the way sherry tastes and you'll get the idea as sherry is a deliberately oxidised.

It is possible to by products that have not been sulphured and most health food shops will stock the non sulphured variety of many products.

Some people have a sensitivity to sulphur and it can make people sneeze, flush red in the face or increase the symptoms of Asthma.

The over use of sulphur is also undesirable and can lead to a eggy smell in products.

A2: Its major use is in the production of sulfuric acid: a very important catalyst and drying agent in industry, a drain cleaner, and it is also used to process wood pulp into newsprint. Sulfur dioxide was used a lot in old refrigerators--like the G.E. "monitor-top" seen in "the Waltons". It is toxic so it was replaced by freon in the 'thirties.