Ascorbic acid and citric acid can be found in a variety of fruits and vegetables.
They are often confused with one another because of their similar names and similar sources of origin, however, ascorbic acid and citric acid are not the same.
Ascorbic acid is vitamin C and citric acid is an acidic antioxidant. The two share several similarities, but also have quite a few fundamental differences.
What Is Ascorbic Acid?
Our bodies cannot make their own vitamin C. Most adults are recommended to consume between 75 and 120 milligrams per day through food or supplements, per the NIH.
Vitamin C is associated with the prevention of a variety of diseases, including, age-related macular degeneration, cancer, cataracts and the common cold. Vitamin C can also increase collagen production, which may improve and help repair ligaments and tendons, per a January 2017 study in the American Journal of Clinical Nutrition.
Ascorbic Acid Uses In the Food Industry
Have you ever heard the advice to squeeze some lemon juice on apple slices to prevent them from going brown?
This technique can be effective because the natural ascorbic acid preservative in the lemons helps retain the natural color of fruits like apples, as well as vegetables and meats, after they are exposed to oxygen, according to Utah State University Extension.
Ascorbic acid is often used in the food industry because, as a potent antioxidant, it functions as a preservative that can help delay food spoiling that occurs due to bacteria, fungi, yeasts, mold and air exposure.
The FDA says that antioxidants also prevent fats and oils in foods from becoming rancid and tasting bad as well as preventing fresh fruit from turning brown. Vitamin C preservative is most commonly found in products including:
- Fruit sauces and jellies
- Cured meats
- Baked goods
- Oils and margarines
- Fruits and vegetables
- Snack foods
You can often find ascorbic acid for preventing darkening when canning or freezing fresh fruits in specialty food stores and pharmacies.
Ascorbic acid may also be used to replace lost nutrients from food processing, the FDA notes. Vitamin C may be added to products such as flours, cereals, margarine, milk, fruit beverages, energy bars, instant breakfast drinks, bread, macaroni and rice, among others.
The World Health Organization (WHO) says that the fortification of milk with iron and vitamin C can help reduce iron deficiency in infants and young children. This is because vitamin C helps with iron absorption, preventing iron deficiency anemia.
What Is Citric Acid?
Citric acid is naturally present in a variety of different fruits and vegetables, per March 2017 research in Chemistry Central Journal.
Foods high in citric acid include berries like raspberries and strawberries, and citrus fruits like lemons and limes. Citric acid is most concentrated in lemons and limes; their juice contains 1.44 and 1.38 grams of citric acid per ounce, respectively.
Citric acid can also improve the activity of other antioxidants. Citric acid may get a bad reputation, because it has been linked to the erosion of tooth enamel, but it also has health benefits. In addition to its antioxidant activity, citric acid may help prevent kidney stones, according to December 2014 research in the Korean Journal of Urology.
Citric acid is also manufactured and used in a number of commercial products. It is a very common food additive.
It's used to give citrus-flavored soft drinks their signature fruity, tart taste and as a flavor and color enhancer in other products. Citric acid is also frequently used as a preservative.
You may find it in juices made from concentrates, vegetable oils and in products used to extend the lifespan of freshly cut produce, per an October 2015 study in the Journal of Functional Foods.
Citric Acid vs. Ascorbic Acid
Citric acid and ascorbic acid (vitamin C) have both similarities and differences.
The similarities between citric acid and vitamin C come down to the fact that they are both acids commonly found in citrus fruits. They also both have antioxidant properties and antimicrobial properties, per the Journal of Functional Foods. As a result, they both have various health benefits.
It's certainly possible for foods to contain both substances. Lemons, for example, have both citric acid and vitamin C.
That said, citric acid and ascorbic acid should not be confused with one another.
Unlike vitamin C, citric acid is not one of the recommended vitamins and minerals you need each day. Citric acid also has not been linked to the prevention of diseases or connective tissue repair, unlike ascorbic acid.
Citric acid also does not have the same effects on the immune system and levels of cholesterol as vitamin C.
These important differences mean citric acid has many more commercial uses — unlike nutrient vitamin C, citric acid is also used in cleaning products, cosmetics and pharmaceuticals.
- National Institutes of Health: "Vitamin C"
- Journal of Endourology: "Quantitative Assessment of Citric Acid in Lemon Juice, Lime Juice, and Commercially-Available Fruit Juice Products"
- Food Science and Technology: "Effect of Ascorbic Acid in Comparison to Citric and Lactic Acid onListeria monocytogenes Inhibition at Refrigeration Temperatures"
- Nutritional Management of Renal Disease (Third Edition): Chapter 24 - Vitamin Metabolism and Requirements in Renal Disease and Renal Failure
- FDA: "Overview of Food Ingredients, Additives & Colors"
- WHO: "The role of food fortification in the control of micronutrient malnutrition"
- Utah State University Extension: "Pretreatments to Prevent Darkening of Fruits Prior to Canning or Dehydrating"