Every time you enjoy citrus fruits, such as lemons and limes, you consume citric acid produced by nature. Commercially-made citric acid gets added to foods and beverages as a flavoring agent, cleaning products for its softening and disinfectant properties and medications to mask taste.
Most manufactured citric acid that you find in everyday commercial products comes from a fungus put through a fermentation process using a low-cost molasses.
Read more: 5 Tricky Fruits and How to Eat Them
Citric Acid Production
Not all citric acid gets manufactured — you'll find the acid in nature or in the produce section of your local grocery store. According to a December 2015 review from the BMC Chemistry journal, citrus fruits can come in several forms and sizes, from round to oblong, and the most commonly known are as follows:
- Citrons (a large fruit with a thick rind, similar in color to lemons)
Citrus fruit is grown in more than 140 countries and 6.13 million tons was used in the U.S. during the 2017 to 2018 season, according to the USDA.
Unlike natural citric acid, up until the 1900s, the majority of the world's manufactured citric acid came from Italy, where organizations extracted it from fresh fruits. Then researchers discovered that strains from a fungi known as Aspergillus niger could produce citric acid when fermented using a low-cost molasses as the raw material.
Because of the cost efficacy and ease of use, this method is still used for approximately 90 percent of the world production of citric acid today, per an August 2018 article from Toxicology Reports, which analyzed the history of citrus acid.
Where You Find Citric Acid
Citric acid you see listed on ingredient labels is of the manufactured kind. This citrate gets added to thousands of merchandise worldwide, including:
- Approximately 70 percent of manufactured citric acid gets used in the food and beverage industry, according to Toxicology Reports. Half of this produced acid is combined with soft drinks and other beverages, where the additive boosts flavors and produces a slightly sour taste.
- Citric acid also acts as a preservative in jams, gelatins, candies, frozen foods, canned vegetables and meat products because it maintains the stability of active ingredients, per the National Center for Biotechnology Information (NCBI).
- Because of its ability to preserve foods, canning food enthusiasts use citrus acid to prevent bacterial growth.
- Per the NCBI, citric acid can act as a water-conditioning agent, serve as a detergent builder, clean and polish stainless steel and other metals and remove sulfur dioxide from smelter waste gases.
- A November 2015 study from Applied and Environmental Microbiology found that citric acid serves as a valuable disinfectant combating bacteria.
- A March 2017 review in BMC Chemistry found that citrate can serve as a safe, harmless adversary of several viruses, including human norovirus. A commercial paper tissue with just more than 7.5 percent of citrus acid between the middle layer kills the viruses emitted in tiny droplets on the tissue paper after coughing, sneezing and blowing the nose.
- According to the NCBI, citric acid is used in pharmaceutical preparations due to its antioxidant properties and powerful ability to change the unappealing flavor of raw medicine.
- The Cleveland Clinic says that citric acid can transform blood and urine, making them more alkaline. This works to prevent kidney stones.
- Citric acid can also treat a condition called metabolic acidosis, a disorder in which a body produces too much acid, according to the Cleveland Clinic.
- Toxicology Reports: “Potential Role of the Common Food Additive Manufactured Citric Acid in Eliciting Significant Inflammatory Reactions Contributing to Serious Disease States: A series of Four Case Reports”
- BMC Chemistry: “Citrus Fruits as a Treasure Trove of Active Natural Metabolites that Potentially Provide Benefits for Human Health”
- United States Department of Agriculture: “Citrus Fruits”
- Applied and Environmental Microbiology: "Inactivation of Foot-and-Mouth Disease Virus by Citric Acid and Sodium Carbonate with Deicers"
- BMC Chemistry: "Citric Acid: Emerging Applications of Key Biotechnology Industrial Product"
- Cleveland Clinic: "Citric Acid; Sodium Citrate Oral Solution"
- National Center for Biotechnology Information: "Citric Acid"