Acidulants are chemical compounds added to food and beverages to provide a tart, sour, or acidic flavor and to act as preservatives. They work by lowering the pH of a product, which can also help with other functions like adjusting flavor, acting as a leavening agent, and maintaining color and texture. Common examples include citric acid, malic acid, and acetic acid, fumaric acid often used in everything from candies and drinks to baked goods.