Citric acid is a natural, weak organic acid that is found in many fruits and vegetables, especially citrus. Because citric acid is also a byproduct of the citric acid cycle, it is also produced by many living organisms, including mold.
Citric acid is prized for its sour flavor, preservative quality, and ability to act as a pH buffer. For these reasons, citric acid is found on the ingredient list of many food products today.
Approximately 50% of the world’s citric acid production is used as a flavor enhancer in beverages. Citric acid is used in soft drinks, teas, juices, and other beverages to create a slightly tart, refreshing flavor and balance sweetness.
The acidic pH of citric acid also makes it useful as a preservative. Since many bacteria are unable to grow in an acidic environment, citric acid is often added to jams, jellies, candy, canned foods, and even meat products as a preservative.
Because citric acid can be made in a powder form, it can be used in dry foods when a sour flavor is desired. Citric acid is therefore a dry alternative to lemon juice or vinegar in dry foods such as seasoning salts, flavoring powders, and crunchy snacks.
Citric acid is sometimes used to create an acidic environment and facilitate the ripening process when making cheese, particularly mozzarella.
The acid pH of citric acid also makes it useful as a dietary supplement. Many minerals require an acidic pH for absorption. Citric acid is added to vitamin supplements to make some vitamins biologically available for absorption.