Why are sulfites used in some food products? Sulfiting agents are food additives permitted for use in some foods. Sulfites are inorganic salts that have antioxidant and preservative properties. Many compounds capable of producing sulfite, called sulfiting agents, have been used as food additives since antiquity to help preserve foods by preventing browning of light-colored fruits and vegetables; controlling growth of microorganisms; acting as bleaching agents; and other functions.
Examples of sulfiting agents include: sulfur dioxide, sodium sulfate, sodium and potassium bisulfites, and metabisulfites. Specifically, sulfites are used on fruits and vegetable to prevent unpleasant browning, on shrimp and lobster to prevent melanosis, or “black spot”, in wines to discourage bacterial growth, in dough as a conditioner, and to bleach certain food starches and cherries. In addition, sulfites are used in pharmaceuticals to maintain the stability and potency of some medications. Sulfites occur naturally in some foods and beverages as a result of fermentation, such as in beer and wine.
As a food additive, sulfites have been used since 1664 and have been approved for use in the United States since the 1800s. With such a history of use, sulfites have been generally regarded as safe (GRAS) by the FDA, however it is suspected that a small percentage of the population is sensitive to sulfites. This sensitivity can cause a wide range of reactions ranging from mild to severe.
Sulfite sensitivity. Sensitivity to sulfites can develop at any time during a person’s lifespan, and may appear as a skin reaction, or trouble breathing. Asthmatics that are steroid-dependent may be at an increased risk of having a reaction to a sulfite containing food. Adverse reactions to sulfites in nonasthmatics are rare. Symptoms of sulfite intolerance can occur within 15 to 30 minutes following oral exposure. While the majority of reactions are mild, severe nonspecific reactions do occur on occasion.
Regulations. Even though sulfites are safe for most people to consume, they could pose a hazard of unpredictable severity to asthmatics and others who are sensitive to them. In response, the FDA has restricted the use of sulfites in certain foods.
- The use of sulfites to maintain color and crispness of fresh fruits and vegetables, such as on a salad bar or at retail, is prohibited.
- Labeling is required for foods which contain 10 parts per million (ppm) of sulfite, or more.
- The USDA also prohibits the use of sulfites on meat because sulfites may give the appearance of false freshness by restoring red color to raw meat.
Recommendations for sulfite-sensitive individuals. Those with sensitivity to sulfites should take precautions when buying unlabeled foods at a deli, supermarket, or food service establishment:
- If the food is being sold loose or by portion, ask the store manager or waiter to check the ingredient list on the products original bulk size packaging.
- Avoid processed foods that may contain sulfites, such as dried fruits, canned vegetables, maraschino cherries, and guacamole.
- When ordering a potato, opt for a baked potato over any kind that involves peeling of the vegetable during preparation.
A list of foods and drugs that may contain sulfites is listed on the University of Florida Extension web site.
Stay safe and healthy! Barb