Food additives are natural and artificial substances that are added to food to preserve flavor or enhance its taste and appearance, however sometimes these additives can negatively affect human health. Food additives include natural ingredients like ascorbic acid (vitamin C) and gelatin, as well as controversial ingredients like partially hydrogenated vegetable oil (trans fat) and aspartame. Examples are flavor enhancers (saccharine and monosodium glutamate, commonly known as MSG), preservatives (sodium nitrate, sulfites and nitrates), stabilizers and emulsifiers (xantham gum and tricalcium phosphate), and coloring agents (Caramel, Violet BNP and Brown FK).