Alum

Alum is a group of aluminum-containing salts, most commonly potassium aluminum sulfate. It is found naturally in mineral deposits and can also be manufactured. Alum has been used for centuries in various applications, including food preparation.

In food, alum is primarily used as a firming agent, especially in pickles and preserved fruits and vegetables. It helps maintain their crisp texture during processing and storage. It can also be found in some baked goods as part of a leavening system.

In the U.S., alum is generally recognized as safe (GRAS) by the FDA for use as a food additive. Regulatory bodies like JECFA and EFSA have evaluated alum, and JECFA has established an acceptable daily intake. While generally considered safe at typical food levels, very high doses of aluminum can be harmful. Some research has explored potential links between high aluminum intake and health concerns, but evidence at typical dietary levels is not conclusive.