Citric acid is a weak organic acid that is naturally found in citrus fruits, such as lemons, limes, and oranges. It is commonly used as a food preservative and flavoring agent. Citric acid has a tart, sour taste and is often used to add a tangy flavor to beverages, candies, and other food products. It is also used as a preservative to extend the shelf life of certain foods, such as canned fruits and vegetables.