100% Pure Malic Acid (e296) is an organic compound, which is the active ingredient in many sour or tart foods. In nature malic acid is present in large concentration on the apple skin and in a wide range of fruit and vegetable products, including plums, tomatoes, currant berries, bananas. In addition to being an acid regulator, malic acid is added to foods to give them a richer and more penetrating aroma. It is more tart than either ascorbic or citric acid.