As the ammonium salt of citric acid, ammonium citrate is composed of colorless crystals that are soluble in water. Its most typical use is as a food additive, primarily as an acidity regulator and color stabilizer in lemonades, fruit and vegetable preserves, ready-made soups, baked goods, jams, and frozen fish. This salt is often replaced with a substitution of ammonium ferric citrate, as the addition of the iron in ammonium ferric citrate allows for more rapid solubility in water and also adds trace amounts of the necessary mineral nutrient to foods that would otherwise provide no additional mineral fortification. The EU classifies ammonium citrate as E380, and it is considered non-toxic in moderate quantities. Beyond its use as a food additive, ammonium citrate has few laboratory or industrial uses since citric acid is readily available from both natural and synthetic sources. Ammonium acetate should be kept in a moisture and airtight container.