Sodium sulfite is a soluble sodium salt of sulfurous acid and its chemical formula is Na2SO3.

Used in food processing to sterilize fermentation equipment and food containers to inhibit undesirable micro-organisms growing.

Sodium sulfites are added to pre-peeled and sliced/chopped apples and potatoes to prevent oxidative discoloration and control enzymic browning.

Sodium sulfites are used in processing sugar beet, corn sweeteners, food starches and gelatine.

In some countries sodium sulfites are added to fresh sausages to control Enterobacteriaceae, including Salmonella. Sodium sulfites also preserve the bright-red colour of meat by inhibiting the oxidation of myoglobin to metamyoglobin. This will reduce the B1, Thiamine content in sulfite treated meat products.

Sulfites modify the properties of dough by the sulfitolysis of disulfite bonds in the gluten. Adding sulfites to the dough has several technological advantages, reducing the time to mix the batch and reducing the elasticity of the dough allowing continuous biscuit producing. Adding sulfites into the dough makes the baked products consistent, even when various varieties of wheat may be used.

Asthma related symptoms like wheezing or respiratory irritation are really common from sodium sulfites. Severe respiratory symptoms can include narrowing of the airways and difficulty breathing.  Sulfuric dioxide gas is liberated from sulfites in acid food and inhaled when the food is swallowed and this causes an asthma attack.

Respiratory symptoms are not the only symptoms what you can get from sulfites, particularly from sodium sulfites. Other symptoms can be nausea, gastric irritation, diarrhea, abdominal bloating and pain, headaches, brain fog, hot flashes, high or extremly low blood pressure, skin rashes, swellings in any part of the body etc.

Food products where you might find sodium sulfites:

• Preserved egg yolk
• Fresh sausages and raw meat (even though this is forbidden in many countries it still happens)
• Quick-frozen shrimps, lobsters
• Wine
• Beer
• Concentrated fruit juices, specially pineapple juice
• Pre-peeled and sliced/chopped fruits and vegetables like apples and potatoes or other ones which have light colour
• Beet sugar
• Corn sweeteners
• Food starches
• Gelatine
• Various baked goods, in biscuits particularly
• Manufacturing of caramel colour E150

‘Tiiu’s note: No wonder so many people are reacting to baked goods containing gluten- in many cases it is not probably the gluten or for instance wheat we are reacting to, it is all the ADDED chemicals like sulfites in these foods. I stopped eating gluten in 2000, and before that I reacted really violent ways to all baked products. Still today I get reactions just being near by certain bakeries or places where baked good are re-heated. I even used to react to gluten containing flours, when someone was baking. From my own personal experience I know that added sulfites in flours/baked goods can be found in most of the countries in Europe and in Asia.’