Sulfites are sulphur-based chemical compounds that sometimes occur naturally in foods but are also used as preservatives. According to the Food and Drug Administration, approximately one out of every 100 people is sensitive to sulfites. Most reactions are mild, but some people, particularly those with asthma, have severe reactions. Sulfites were used as a preservative on fresh fruits and vegetables until 1986, when the FDA banned this use.
Six sulfiting agents are used in food preparation in the U.S.: potassium bisulfite, potassium metabisulfite, sodium bisulfite, sodium metabisulfite, sodium sulfite and sulfur dioxide. Any sulfite occurring in a concentration of greater than 10 parts per million must be listed on the ingredients list of a food product.
Sulfites occur in baked goods including mixes with dried fruits and vegetables, crackers, pie crusts, soft pretzels and waffles. Condiments with sulfites include pickles, wine vinegar, jam and salad dressing mixes. Frostings and toppings with sulfites include powdered sugar, maple syrup, packaged frosting mixes, brown sugar, raw sugar, white sugar and fruit toppings. Fish with sulfites include canned shrimp, scallops, frozen shrimp, crab and canned clams. Snacks with sulfites include dried fruit snacks, pudding, hard candy, potato chips and trail mix. Grain products with sulfites include spinach pasta, rice mixes, cornstarch and gravies. Fruit and vegetable products with sulfites include maraschino cherries, canned vegetables, instant mashed potatoes, all dried fruits, chives, spices, raisins, bottled fruit, glazed fruit, fresh potatoes, dried vegetables and potato salad.
Sulfites occur naturally in the fermentation process used to make wine, beer and liquor, and are also found in wine coolers. You can find sulfites in canned, bottled and frozen fruit juice; vegetable juice; drinks containing corn syrup; cocktail mixes; lemonade mixes, and liquid tea concentrates.