Acidic Components of Soft Drinks
- Phosphoric acid is used in colas because other acids like citric acid introduce undesired citrus flavors into the beverage. In colas, 85 percent-strength phosphoric acid can be used in the ratio of 0.3 oz. per 6 gallons. This is the acid responsible for the "bite" in a cola's flavor. The top three most acidic sodas in a study of 20 different commercial soft drinks published in the journal "General Dentristry" were colas. Coke was third on the list with a pH of 2.525.
- The actual amount of an acid in a soda may be quite small. When added to soft drinks with lower acid requirements like birch beer, cream soda or root beer, the citric acid content can be as low as 0.2 oz. to 6 gallons of soda. Citric acid lends tartness, which usually has to be regulated with the addition of sodium citrate. As the acidic component of soft drinks, citric acid is the most-widely used acid for non-cola drinks. While being less acidic than phosphoric acid, it is also more erosive to tooth enamel.
- A naturally occurring acid in fruits like apples, pears and tomatoes, malic acid is an alternative to citric acid in soft drinks. It may be the preferred acid for apple-based drinks or low-calorie drinks, despite being a relatively more expensive acid. For berry-flavored soft drinks, malic acid may be incorporated into the formulation. The acid content of berry sodas may be as little as 0.85 oz. for 6 gallons of product.
- As a derivative of malic acid, fumaric acid is less widely used in food and drink applications due to its strong flavor. Some powdered drinks may contain fumaric acid.