Tricalcium citrate is the calcium salt of citric acid, used as a food additive designated E333 in Europe. It serves as an acidity regulator, firming agent, and sequestrant: it steadies pH, helps jams and jellies set, firms canned vegetables, and binds metal ions that would otherwise catalyse spoilage or discoloration. Because it supplies calcium in a soluble, neutral-tasting form, it is also used to fortify beverages and foods with calcium. Citrates are among the most benign food additives — citric acid is a normal product of human metabolism — and tricalcium citrate is considered safe at permitted levels. It appears on ingredient lists by name or E number.