Citric acid is a weakorganic tricarboxylic acid having the chemical formula C6H8O7. It occursnaturally in citrus fruits. In biochemistry, it is an intermediate in thecitric acid cycle, which occurs in the metabolism of all aerobic organisms. Acitrate is a derivative of citric acid; that is, the salts, esters, and thepolyatomic anion found in solution. Citric acid exists in greater than traceamounts in a variety of fruits and vegetables, most notably citrus fruits. Citricacid exists in a variety of fruits and vegetables, but it is most concentratedin lemons and limes, where it can comprise as much as 8 percent of the dryweight of the fruit. Citric acid is a common food additive and is found ineverything from sodas to candies.
Usesand Applications
Approximately 50% of theworld’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 createa slightly tart, refreshing flavor and balance sweetness. Because citric acidcan be made in a powder form, it can be used in dry foods when a sour flavor isdesired. Citric acid is therefore a dry alternative to lemon juice or vinegarin dry foods such as seasoning salts, flavoring powders, and crunchy snacks. Manyby-products and residues of the agro-industry can be used in the production ofcitric acid. A cost reduction in citric acid production can be achieved byusing less expensive substrates.