Sulfur dioxide as a preservative in wines and dehydrated fruits

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1 min reading time

1.                  Introduction:

 

From the moment a food is harvested, whether it is a food of plant origin or a food of animal origin, the endless battle of man begins against the germs that can spoil it or cause diseases to him. The process that man applies in order to extend the shelf life of food is called maintenance and can be done either by using natural methods, such as dehydration, cooling, freezing, etc. or by using special substances called preservatives and belong to food additives. One of the preservatives used is sulfur dioxide (E220).

 

 

2.                  The use of sulfur dioxide in food preservation:

 

Sulfur dioxide is used both in the production of wines or in the production of dehydrated fruits for the preservation of these products.

 

In the case of wine production, the process of adding sulfur dioxide (sulfite anhydride) is called sulfation and is made in the must.

Sulfur dioxide:

1.                  Protects against unwanted oxidative reactions.

2.                  Inhibits alcoholic fermentation, which is crucial in the production of sweet wines.

3.                  It slows down the conversion of alcohol to acetic acid, so wine to vinegar.

4.                  Facilitates the transfer of phenolic compounds and organic acids from the skin of the grape to its juice.

 

In the case of dehydrated fruits, such as dehydrated apples, apricots and figs, in addition to the antimicrobial action it exerts, it also protects the color, as it inhibits the action of enzymes that can cause the so-called enzymatic tan.

 

3.                  Effects on human health from the use of sulfur dioxide as a preservative:

 

Most people tolerate small amounts of sulfur dioxide in their diet, but for some, it can cause allergic reactions or other side effects, such as headaches. Sulfur dioxide and other sulfites significantly reduce the intake of vitamin B1, which can cause many health problems such as chronic headache and temporary amnesia. Patients with asthma are particularly at risk, in whom even ingestion of less than 10 mg of sulfites can cause an asthma attack.

 

Although carbon dioxide poses serious health problems for consumers, it is still used today in the preservation of wines and dehydrated fruits, as it is the only preservative that can inhibit the growth of 90% microbes in these foods.

 

4.                  Research into the replacement of sulfur dioxide by other substances:

 

In recent years, serious efforts have been launched at European level to replace sulfur dioxide. More specifically, in the framework of the European Research project so2say, natural extracts have been discovered that can replace sulfur dioxide in red wine and other foods. According to the results of the project, researchers may now have identified a combination of two extracts of natural origin that can replace SO2. Especially in the case of wine, the presence of SO2 could be limited to more than 95%. Wines with the new additive have already been tested in the United Kingdom, Spain and Germany and were considered equivalent to reference bottles containing sulfur. The tests are continuing and, if the technical feasibility of the new extract is proven, the procedures for granting the relevant license will be initiated.

 

 

By Thomas Zaferiadis

Food Technologist MSc - Veterinarian

 

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