Citric acid occurs naturally in some foods, particularly fruit, and it is a common additive in certain foods and beverages. It serves various purposes as an additive, explains the U.S. Food and Drug Administration. Citric acid functions as a preservative, combating food spoilage and degradation. It also helps regulate the acidity, or pH, of food products and adds a sour or acidic taste to foods and beverages.
All citrus fruit has naturally-occurring citric acid. Common citrus fruits include lemons, limes, oranges, clementines, tangerines and grapefruit. The various types of lemons and limes have the highest amount of citric acid, which can account for almost 10 percent of their dry weight, according to Oxford's Hands-On Science Project. Juice and fillings made from citrus fruits of course also contain citric acid. Lemon juice is a widely-used ingredient in an array of products, so always check for it on labels.
Berries, with the notable exception of blueberries, contain naturally-occurring citric acid. Those containing higher amounts include strawberries, raspberries, cranberries, red and black currants, and gooseberries, notes the Citric Acid Intolerance Page. Berry juices, jams, jellies, preserves, and other spreads and fillings also contain citric acid.
Many other fruits have at least low levels of naturally-occurring citric acid. Exotic fruits, such as pineapple and tamarind, usually contain the compound. Drupe or stone fruits, such as cherries, peaches and apricots also have citric acid. Juices and other products made with these fruits contain citric acid, too. Fresh and canned tomatoes contain citric acid as well, as do tomato-based products such as juices and sauces. Wine also has citric acid, which accumulates during the fermentation process, and is sometimes added for flavor, points out the Citric Acid Intolerance Page.
Breads classified as sourdoughs, including standard sourdough bread, rye, pumpernickel and Amish friendship bread contain citric acid. It is added to some for flavoring purposes, while others create citric acid as a byproduct of the fermentation process.
Citric acid is sometimes used in cheese-making as an emulsifying agent for the water and oil content, and to improve the texture and body of the final product, explains the APAC Chemical Corporation. It can be used to aid curd formation, as well, and is more common in soft cheeses, notes CheeseForum.org.
Citric acid is added to a variety of other foods and beverages, and can be found in ingredient lists on packaging. Condiments and dressings likely contain citric acid, often because they're made with lemon juice. Fruit-flavored candy and frozen desserts often have citric acid, as do most soft drinks.