What Is Citric Acid?

cut lemons with bowl of citric acid

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Citric acid is a natural component of fruits and fruit juices, with the most significant amounts found in citrus fruits. It's what gives lemons and limes their characteristic sour flavor. Lemons and limes contain the most citric acid of any fruit, but other citrus fruits like oranges and grapefruits—and even some berries—contain large amounts as well.

Health Benefits

One of the most important roles of citric acid is its involvement in energy metabolism. In fact, the citric acid cycle (also known as the Krebs cycle) is the metabolic pathway by which foods are broken down into water, carbon dioxide, and energy.

Citric acid may also prevent or slow the formation of kidney stones. When citric acid is in your urine, it binds with calcium, breaks up small stones that may be forming, and deters stone formation from happening by altering the pH.

Another benefit of citric acid is that it increases your body's absorption of certain minerals like magnesium, calcium, and zinc.

Citric Acid in Food

Citric acid is most often naturally found in citrus fruits and juices, but it is also present in smaller amounts in other fruits. Some foods that naturally contain citric acid include:

  • Lemons
  • Limes
  • Grapefruits
  • Oranges
  • Pineapples
  • Cherries
  • Raspberries
  • Strawberries
  • Cranberries
  • Grapes
  • Tomatoes

Uses

Citric acid is most commonly manufactured and used as a food additive. About 70% of all manufactured citric acid is used as an additive to food. But manufactured citric acid is also used in medications, dietary supplements, and some cleaning products.

Food Additive

Citric acid is used both as a natural flavor enhancer and preservative in a variety of foods, such as jams and jellies and canned fruits and vegetables. It's also used in ice cream, fruit drinks, candy, and carbonated beverages. It helps regulate acidity, functions as an antioxidant, and helps retain color. Because of its low pH and acidic profile, citric acid can also help protect against botulism in canned goods and other preserved foods.

Citric acid was first produced in England from lemons in the early 1800s. Lemon juice was the primary source of citric acid until 1919, when the first industrial process using a bacteria called Aspergillus niger began in Belgium. Now, about 99% of the world's manufactured citric acid used as a food additive today is made by fermenting A. niger.

Medication and Dietary Supplements

Citric acid and its close relative citrate are used as inactive ingredients in certain medications and dietary supplements. Citrate can be used to control the pH and mask the bitter taste of some medicines because of its acidity and slightly sour taste. It is also often added to supplements to make nutrients such as magnesium, calcium, and zinc more bioavailable and easier to absorb.

Cleaning Products

Citric acid and citrate are commonly used in household and commercial cleaning solutions to remove stains, odors, and hard-water buildup. Just as when used as a food or drug additive, its natural acidity also makes it useful in controlling the pH of household cleaners.

Because of citric acid's antibacterial and antiviral properties, it can be used as an effective disinfectant in home, commercial, and clinical settings.

Safety

The Food and Drug Administration (FDA) considers citric acid to be safe for use as a food additive. It appears that all the citric acid you consume is completely metabolized in your body—there's no toxic build-up, and it's not stored.

However, because manufactured citric acid is made by fermenting the bacteria A. niger (which is essentially black mold), some researchers feel that there is a potential for an inflammatory response when eating foods with citric acid added to them.

There are some anecdotal reports of people who are sensitive to foods that contain manufactured citric acid. In these cases, people experienced increased inflammatory symptoms after consuming these foods but did not have any symptoms when eating foods containing natural forms of citric acid. It's difficult to determine if someone has an actual citric acid allergy or sensitivity because it's found in, or added to, so many different foods.

Something else to watch out for with citric acid is its effect on your tooth enamel. Consuming excessive amounts of citric acid (like acidic drinks such as soda) over a long period of time can lead to the erosion of your tooth enamel. You can counteract this effect by rinsing your mouth with water after, drinking through a straw, consuming these acidic drinks in moderation, or even better—swapping soft drinks with water.

A Word From Verywell

Natural sources of citric acid include citrus fruits and other produce and are safe to eat. However, most of the citric acid we consume comes from manufactured sources. While the citric acid found in food additives is generally considered safe by the FDA, there have been some anecdotal reports of inflammatory reactions after consuming foods with manufactured citric acid. Before making any changes to your diet, consult with your physician.

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