Malic acid in soft drinks

Most sweet drinks, including diet soft drinks, contain orthophosphoric, carbonic and citric acids; malic, tartaric and other organic acids may also present. The function of introducing acidity into soft drinks is to balance the sweetness and also to act as a preservative.

In nature, malic acid is found in the L-form in many fruits such as apple, and indeed it is sometimes called apple acid, and contributes to the sour taste of green apples.

A crystalline white solid (mp 100 °C), it is highly soluble in water. Being less hydroscopic that citric acid it possesses improved storage and shelf-life properties.

Malic acid finds use in a variety of products mostly in fruit-flavored carbonates. It is the preferred acidulant in low-calorie drinks and in cider and apple drinks, enhancing flavor and stabilizing color in carbonated and non-carbonated fruit flavored drinks.

Malic acid is slightly stronger than citric in terms of perceived palate acidity and imparts a fuller, smoother, fruity flavor.
Malic acid in soft drinks