Citrus Acidic Foods & Tin Foil

Citric Acid

• Foods such as citrus fruits, raspberries and tomatoes naturally contain citric acid. It is also often used to make cheese, as well as widely used as a preservative, emulsifier and flavoring. When it comes into contact with aluminum it converts it into aluminum salts. For this reason, foods high in citric acid shouldn't be stored in direct contact with non-anodized aluminum foil or aluminum cookware.

Aluminum Reactions

• When aluminum foil comes into contact with foods that contain citric acid, excessive salt or spices, it can react. It may turn black or even dissolve in spots. This reaction can also occur if aluminum foil comes into contact with a non-aluminum metal in a moist environment. This reaction can be prevented by putting a sheet of parchment paper between the aluminum foil and the food or by using glass, plastic or ceramic storage containers.

Cooking With Aluminum

• Despite the caution against storing citric acidic foods in aluminum, it is safe to cook in aluminum cookware, even if the food is acidic. Most aluminum cookware, and some brands of aluminum foil, is anodized. This means that a protective coating has been applied that prevents the food from coming into direct contact with the aluminum itself, thus preventing the reaction which leads to the formation of aluminum salts.

Health Risks

• Some medical professionals have raised concerns about the levels of aluminum that we ingest, because of the higher levels of aluminum in the brains of Alzheimer's patients. However, these concerns have been largely disregarded. Many medicines, such as antacids, contain a high amount of aluminum salts, and aluminum is even in products such as deodorant. The amount of aluminum ingested from the foods we eat and store in aluminum foil is much smaller than what we encounter when using these products. There are huge amounts of aluminum on the planet and it is in many of the things that we ingest, from the water to plants, and so on up the food chain. It is very hard to avoid the ingestion of aluminum in one form or another. "If it were toxic to living creatures," says Dr. John Messmer, an associate professor at Penn State College of Medicine, "there would not be many around."