Vitamin C Ascorbic Acid

Vitamin C (also known as ascorbic acid and ascorbate) is a water-soluble vitamin found in citrus and other fruits and vegetables, also sold as a dietary supplement[9] and as a topical 'serum' ingredient to treat melasma (dark pigment spots) and wrinkles on the face.[10] It is used to prevent and treat scurvy.[9] Vitamin C is an essential nutrient involved in the repair of tissue, the formation of collagen, and the enzymatic production of certain neurotransmitters.[9][11] It is required for the functioning of several enzymes and is important for immune system function.[11][12] It also functions as an antioxidant.[13] Most animals are able to synthesize their own vitamin C. However, apes (including humans) and monkeys (but not all primates), most bats, some rodents, and certain other animals must acquire it from dietary sources.

Food additives[edit]

Ascorbic acid and some of its salts and esters are common additives added to various foods, such as canned fruits, mostly to slow oxidation and enzymatic browning.^[107] It may be used as a flour treatment agent used in breadmaking.^[108] As food additives, they are assigned E numbers, with safety assessment and approval the responsibility of the European Food Safety Authority.^[109] The relevant E numbers are:

1. E300 ascorbic acid (approved for use as a food additive in the UK,^[110] U.S.^[111] Canada,^[112] Australia and New Zealand^[113])

2. E301 sodium ascorbate (approved for use as a food additive in the UK,^[110] U.S.,^[114] Canada,^[112] Australia and New Zealand^[113])

3. E302 calcium ascorbate (approved for use as a food additive in the UK,^[110] U.S.^[111] Canada,^[112] Australia and New Zealand^[113])

4. E303 potassium ascorbate (approved in Australia and New Zealand,^[113] but not in the UK, U.S. or Canada)

5. E304 fatty acid esters of ascorbic acid such as ascorbyl palmitate (approved for use as a food additive in the UK,^[110] U.S.,^[111] Canada,^[112] Australia and New Zealand^[113])

The stereoisomers of Vitamin C have a similar effect in food despite their lack of efficacy in humans. They include erythorbic acid and its sodium salt (E315, E316).^[110]

Chemistry[edit]

ascorbic acid
( reduced form)

dehydroascorbic acid
( oxidized form)

The name "vitamin C" always refers to the l-enantiomer of ascorbic acid and its oxidized forms, such as dehydroascorbate (DHA). Therefore, unless written otherwise, "ascorbate" and "ascorbic acid" refer in the nutritional literature to l-ascorbate and l-ascorbic acid respectively. Ascorbic acid is a weak sugar acid structurally related to glucose. In biological systems, ascorbic acid can be found only at low pH, but in solutions above pH 5 is predominantly found in the ionized form, ascorbate. All of these molecules have vitamin C activity and thus are used synonymously with vitamin C, unless otherwise specified.^{[citation needed]}

Numerous analytical methods have been developed for ascorbic acid detection. For example, vitamin C content of a food sample such as fruit juice can be calculated by measuring the volume of the sample required to decolorize a solution of dichlorophenolindophenol (DCPIP) and then calibrating the results by comparison with a known concentration of vitamin C.^[132][133]

From Wikipedia, the free encyclopedia

https://en.wikipedia.org/wiki/Vitamin_C