Ascorbic Acid vs Sodium Ascorbate
It is the form in which each exists that decides the difference between ascorbic acid and sodium ascorbate. Both ascorbic acid and sodium ascorbateare are forms of Vitamin C and are common food additives, where more specifically sodium ascorbate falls under the category of mineral salts. Therefore, while ascorbic acid is the pure form of Vitamin C, sodium ascorbate is the sodium salt of ascorbic acid.
What is Ascorbic Acid?
As the name suggests, ascorbic acid is acidic in nature and dissolves well in water to give mildly acidic solutions. It is an organic chemical compound with a polyhydroxy function that gives it antioxidant properties. Hence, ascorbic acid is used as a common antioxidant food additive.
Many animals and plants can synthesize ascorbic acid from glucose. However, humans and some higher primates are unable to do so due to the lack of an important enzyme in the ascorbic acid biosynthesis pathway. Therefore, humans are compelled to obtain it through diet to avoid Vitamin C deficiency. The deficiency of Vitamin C can lead to several illnesses such as ‘scurvy,’ which can be deadly. Ascorbic acid was previously called ‘L-hexuronic acid‘ and the main form that occurs in nature is the ‘L’ isomer. However, there exists a D-ascorbic acid that is quite similar to L-ascorbic acid in antioxidant activity but less in Vitamin C activity. Furthermore, the antioxidant activity of ascorbic acid only has a small role in the total vitamin activity. But, for specific reaction in the body, it is important that the correct isomer is present.
Chemical Structure of Ascorbic Acid
What is Sodium Ascorbate?
Sodium ascorbate is the sodium salt of ascorbic acid and is a common mineral salt used as an antioxidant food additive. It is produced through the reaction between equal amounts of ascorbic acid and sodium bicarbonate with further precipitation using isopropanol.
Being a mineral ascorbate, it is buffered and, therefore, less acidic than ascorbic acid. Usually, sodium ascorbate is recommended for people who have gastrointestinal problems associated with ascorbic acid. Sodium ascorbate is considered mild and more abdomen friendly. However, when including sodium ascorbate in diet, it is important to keep in mind that the sodium is also being very well absorbed by the body along with the ascorbic acid. Therefore, the dosage of intake should be carefully monitored. Sodium ascorbate is water soluble and hence can only protect water soluble forms from oxidation. It cannot protect fats from oxidation. Fat soluble esters of ascorbic acid with long fatty chains are required for this purpose.
Chemical structure of (+)-sodium L-ascorbate
What is the difference between Ascorbic Acid and Sodium Ascorbate?
• Ascorbic acid is an organic acid whereas sodium ascorbate is a mineral salt of ascorbic acid.
• The European Food Additive E number for ascorbic acid is E300 and for sodium ascorbate it is E301.
• Sodium ascorbate is milder than ascorbic acid as it is buffered and has less acidity. That makes sodium ascorbate more stomach friendly than ascorbic acid.
• Sodium ascorbate has an ester function whereas ascorbic acid does not have an ester function in it.
Images Courtesy: Chemical structure of ascorbic acid and Chemical structure of (+)-sodium L-ascorbate via Wikicommons (Public Domain)