Citric acid is one of the most common food additives in use today. You may think it is a harmless derivative of lemons, and that used to be so. Today’s citric acid is a whole different story. Here’s what you need to know about this pervasive ingredient.
Among the peculiar names that you will find on ingredient lists at the grocery store is citric acid. It’s a flavoring, a preservative and is used to preserve the texture of some foods. Of all the unpronounceable names you are likely to find on processed food ingredient lists, citric acid may seem the most reasonable, as it invokes the image of a real thing—citric acid deriving from, well, a citrus fruit. So, what’s the big deal?
What is Citric Acid?
Citric acid is an organic acid that is a component of all aerobic living organisms—most abundantly, and not surprisingly, in citrus fruit. This weak acid has been used as an additive in processed foods for more than 100 years as a preservative, a sour flavoring, or an emulsifying agent. Because of its effective preservative properties, citric acid can be found in most canned and jarred foods to prevent botulism.
Known from the eighth century, but first isolated in 1784 by Carl Wilhelm Scheele from lemon juice, industrial scale citric acid production began in the late nineteenth century—made from Italian lemons. World War I interrupted this cycle and an American food chemist, James Currie, discovered a process for making citric acid from mold in 1917. Pfizer started to produce citric acid from molds in 1919.
When life gives you lemons, ask for black mold instead
Industrial food ingenuity has made it so that citric acid can be created from Aspergillus niger—the common black mold found in houses which, in abundance, poses health risks to humans from spore inhalation. Although citric acid can be obtained from lemon or pineapple juice, producing citric acid from A. niger is a far less expensive process.
Don’t forget to feed the black mold
Black mold is able to efficiently (and cheaply) convert sugars into citric acid. By feeding sucrose or glucose—often derived from corn starch—to the black mold, a citric acid solution is created. Corn is highly likely to be genetically modified (GMO).
The resulting solution is filtered out from mold, and the citric acid is precipitated from the solution and processed into the final, useable form using lime and sulfuric acid.
Foods that citric acid is most commonly added to
Ice cream and sorbets
Sodas, cider, beer and wine
Many canned and jarred foods (preserves, canned fruits/veg, sauces, etc.)
Baked goods and cake mixes
Frozen fish (particularly herring, shrimp and crab)
Many processed sweets
Pre-cut and packaged fruits and vegetables
Baby food (read our article on baby food here)
Citric acid is considered to be a harmless additive by food regulating agencies all over the world. However, public concern has arisen from its erosive effects on tooth enamel.
A small percentage of the population is allergic to citric acid, though the allergy may actually be to trace amounts of corn or black mold that may remain after processing.
There are also questions about what part citric acid plays in acid reflux in infants who eat jarred baby food, much of which is preserved with citric acid. People who have peptic ulcers or other GI sensitivities may experience irritation from citric acid.
Citric acid used to be made from fruit. Now it’s more commonly made from feeding sugars to black mold and processed using sulfuric acid. Citric acid is in just about all processed foods. It’s also often found in kitchen cleaners, and does a great job removing mineral deposits from chrome.
Read our Sustainable Kitchen Guide to learn how to buy healthy, humane and sustainable food.