The main difference between ascorbic acid and citric acid is that ascorbic acid is a water-soluble vitamin and has a chemical make-up of C6H8O6, whereas citric acid has one more oxygen atom than ascorbic acid formula, making its chemical formula C6H8O7.
Citric acid and ascorbic acid are two weak natural organic acids that occur naturally in fresh leaves, fruits, and vegetables, particularly citrus fruits such as oranges, lemons, and limes. Both acids have nutritional benefits, and they’re commonly used in food manufacturing and as a preservative, but there are a few differences between the two compounds, including a difference in flavor. However, there seems to be a lot of confusion over the difference between ascorbic acid and citric acid.
Key Areas Covered
Ascorbic Acid, Citric Acid
What is Ascorbic Acid
Ascorbic acid is commonly known as vitamin C. It is an essential nutrient for humans, and it is needed for human tissue growth, repair, and wound healing. Furthermore, it’s also an antioxidant, which helps to protect cells from constituents that damage DNA and improve the function of the immune system. This vitamin is a water-soluble and heat-sensitive vitamin. As a result, it’s not stored in the human body, and it can be destroyed during food processing when foods are heated or canned.
But, ascorbic acid can be incorporated or fortified into foods to increase or substitute vitamin C that is lost during the cooking process. The daily recommended dietary allowance for vitamin C is 75 milligrams for adult women and 90 milligrams for men. However, smokers require an additional 35 milligrams each day.
What is Citric Acid
Citric acid is also a weak organic acid, and it has antioxidant properties. Unlike ascorbic acid, it’s not a vitamin or an essential nutrient. Ascorbic acid acts as an acid buffer and can support to control acidity in the body. Citric acid is also used as a food preservative agent.
Natural sources of citric acid are lemon, lime, grapefruit, and orange juice, as well as lemonade. Citric acid can enhance the bioavailability of minerals like iron, calcium, and magnesium.
Difference Between Ascorbic Acid and Citric Acid
Ascorbic acid is a naturally occurring weak organic acid, whereas citric acid is a weak organic tribasic acid.
Represent a vitamin
Ascorbic acid, also known as vitamin C, is an essential vitamin in the human body, while citric acid is not a vitamin.
The IUPAC name of ascorbic acid is (5R)-[(1S)-1,2-Dihydroxyethyl]-3,4-dihydroxyfuran-2(5H)-one, but the IUPAC name of citric acid is 3-carboxy-3-hydroxypentane-1,5-dioic acid.
Ascorbic acid is also known as Vitamin C, whereas citric acid is also known as 3-carboxy-3-hydroxypentanedioic acid, 2-hydroxy-1,2,3-propanetricarboxylic acid.
The chemical formula of ascorbic acid is C6H8O6, while the chemical formula of citric acid is C6H8O7.
The molar mass of ascorbic acid is 176.12 g·mol−1, but the molar mass of citric acid is 192.12 g·mol−1.
Ascorbic acid is a white or light yellow solid, whereas citric acid is a crystalline white solid.
Ascorbic acid has a density of 1.65 g/cm3, while citric acid has a density of 1.665 g/cm3.
The E-numbers of ascorbic acid include:
- E300 ascorbic acid
- E301 sodium ascorbate
- E302 calcium ascorbate
- E303 potassium ascorbate
- E304 fatty acid esters of ascorbic acid (i) ascorbyl palmitate (ii) ascorbyl stearate
Meanwhile, the E-number of citric acid is E330.
Natural Food Sources
Green leafy vegetables, yellow and green color fruits, and vegetables such as Indian gooseberry, guava, banana, etc. contain ascorbic acid, whereas lemon, lime, grapefruit, lemonade, oranges, and orange juice contain citric acid.
Uses and Functions
Ascorbic acid acts as a powerful antioxidant and enhances the bioavailability of dietary iron, and is used as a food preservative agent. Citric acid, on the other hand, is used as a food preservative agent or a cleaning and chelating agent.
In conclusion, ascorbic acid and citric acid are different weak organic acids, and they have different chemical and sensory properties. The main difference between ascorbic acid and citric acid is that ascorbic acid is a water-soluble vitamin and has a chemical make-up of C6H8O6, whereas citric acid has one more oxygen atom than ascorbic acid formula, making its chemical formula C6H8O7.
1. Lotfy, Walid A.; Ghanem, Khaled M.; El-Helow, Ehab R. (2007). Citric acid production by a novel Aspergillus niger isolate: II. Optimization of process parameters through statistical experimental designs. Bioresource Technology 98 (18): 3470–3477.
2. Zheng, F. Xiao, L.M. Qian, Z.R. Zhou; Xiao; Qian; Zhou (December 2009). Erosion behavior of human tooth enamel in citric acid solution. Tribology International 42 (11–12): 1558–1564.
3. Davies, Michael B.; Austin, John; Partridge, David A. (1991). Vitamin C: Its Chemistry and Biochemistry. The Royal Society of Chemistry. p. 48. ISBN 0-85186-333-7.
2. “Lemons, oranges, and lime” (Public Domain) via Pixbay
3. “Structure of citric acid” by NEUROtiker – Own work (Public Domain) via Commons Wikimedia
4. “L-ascorbic acid” by Yikrazuul – Own work (Public Domain) via Commons Wikimedia