Biological Significance of Ascorbic Acid (Vitamin C) in Human Health - A Review

2003 ◽  
Vol 3 (1) ◽  
pp. 5-13 ◽  
Author(s):  
Khalid Iqbal . ◽  
Alam Khan . ◽  
M. Muzaffar Ali Khan .
Keyword(s):  
Ascorbic Acid ◽  
Vitamin C ◽  
Human Health ◽  
Biological Significance

scholarly journals Role of Vitamin C (Ascorbic Acid) on Human Health- A Review

2005 ◽  
Vol 5 (8) ◽  
pp. 01-12
Author(s):  
Mary K Walingo ◽  
Keyword(s):  
Blood Pressure ◽  
Ascorbic Acid ◽  
Vitamin C ◽  
Human Health ◽  
The Body ◽  
Water Soluble ◽  
Plasma Vitamin ◽  
Risk Of Death ◽  
Increased Risk

Vitamin C, also known as ascorbic acid, abounds in nature and is highly labile. It is a water-soluble vitamin that is lost in large amounts during food processing. It is a vitamin whose prescribed requirement across cultures is not uniform. For example , the prescribed requirement of vitamin C in Great Britain is 30mg/day, while in the U.S.A., it is 60mg/day and 100mg/day in Japan. These variations are unusual and point to the need for further research to establish the acceptable RDAs for diverse populations. The RDA for vitamin C should be more than the amount needed to prevent the occurrence of disease. Vitamin C plays significant functions in the body that enhance its role in the health status of the human body. The biochemical functions of vitamin C include: stimulation of certain enzymes, collagen biosynthesis, hormonal activation, antioxidant, detoxification of histamine, phagocytic functions of leukocytes, formation of nitrosamine, and proline hydroxylation amongst others. These functions are related to the health effects of vitamin C status in an individual. In human health, vitamin C has been associated with reduction of incidence of cancer, blood pressure, immunity, and drug metabolism and urinary hydroxyproline excretion, tissue regeneration. This vitamin is needed for the proper metabolism of drugs in the body through adequate hepatic mixed function oxidase system. Epidemiological data have revealed the preventive and curative role of vitamin C on certain disease conditions in the body though controversies still persist. Vitamin C is effective in protecting against oxidative damage in tissues and also suppresses formation of carcinogens like nitrosamines. There is an inverse relationship with blood pressure and both plasma vitamin C and Vitamin C. Vitamin C has a lowering effect on blood pressure, especially on systolic pressure more than a diastolic pressure. Low levels of plasma vitamin C are associated with stroke and with an increased risk of all cause mortality. Increased consumption of ascorbic acid raises serum ascorbic levels and could decrease the risk of death.

scholarly journals Vitamin C in fleshy fruits: biosynthesis, recycling, genes, and enzymes

2019 ◽  
Vol 23 (3) ◽  
pp. 270-280 ◽  
Author(s):  
D. Y. Tyapkina ◽  
E. Z. Kochieva ◽  
M. A. Slugina
Keyword(s):  
Ascorbic Acid ◽  
Vitamin C ◽  
Biological Significance ◽  
Ascorbic Acid Content ◽  
Plant Secondary Metabolite ◽  
Monodehydroascorbate Reductase ◽  
Fleshy Fruits ◽  
Model Plant Arabidopsis Thaliana ◽  
Ascorbic Acid Biosynthesis ◽  
Plant Arabidopsis Thaliana

L-ascorbic acid (vitamin C) is a plant secondary metabolite that has a variety of functions both in plant tissues and in the human body. Plants are the main source of vitamin C in human nutrition, especially citrus, rose hip, tomato, strawberry, pepper, papaya, kiwi, and currant fruits. However, in spite of the biological significance of L-ascorbic acid, the pathways of its biosynthesis in plants were fully understood only in 2007 by the example of a model plant Arabidopsis thaliana. In the present review, the main biosynthetic pathways of vitamin C are described: the L-galactose pathway, L-gulose pathway, galacturonic and myo-inositol pathway. To date, the best studied is the L-galactose pathway (Smyrnoff–Wheeler pathway). Only for this pathway all the enzymes and the entire cascade of reactions have been described. For other pathways, only hypothetical metabolites are proposed and not all the catalyzing enzymes have been identified. The key genes participating in ascorbic acid biosynthesis and accumulation in fleshy fruits are highlighted. Among them are L-galactose pathway proteins (GDP-mannose phosphorylase (GMP, VTC1), GDP-D-mannose epimerase (GME), GDP-L-galactose phosphorylase (GGP, VTC2/VTC5), L-galactose-1-phosphate phosphatase (GPP/VTC4), L-galactose-1-dehydrogenase (GalDH), and L-galactono1,4-lactone dehydrogenase (GalLDH)); D-galacturonic pathway enzymes (NADPH-dependent D-galacturonate reductase (GalUR)); and proteins, controlling the recycling of ascorbic acid (dehydroascorbate reductase (DHAR1) and monodehydroascorbate reductase (MDHAR)). Until now, there is no clear and unequivocal evidence for the existence of one predominant pathway of vitamin C biosynthesis in fleshy fruits. For example, the L-galactose pathway is predominant in peach and kiwi fruits, whereas the D-galacturonic pathway seems to be the most essential in grape and strawberry fruits. However, in some plants, such as citrus and tomato fruits, there is a switch between different pathways during ripening. It is noted that the final ascorbic acid content in fruits depends not only on biosynthesis but also on the rate of its oxidation and recirculation.

Amperometric assay of vitamin C using an ascorbate oxidase enzyme electrode

1979 ◽  
Vol 44 (11) ◽  
pp. 3395-3404 ◽  
Author(s):  
Pavel Posádka ◽  
Lumír Macholán
Keyword(s):  
Ascorbic Acid ◽  
Vitamin C ◽  
Oxygen Electrode ◽  
Ascorbate Oxidase ◽  
Current Response ◽  
Reaction Conditions ◽  
Long Term Storage ◽  
Oxidase Enzyme ◽  
Optimal Reaction

An oxygen electrode of the Clark type, coated by a thin, active layer of chemically insolubilized ascorbate oxidase from squash peelings specifically detects by measuring oxygen uptake 10 to 400 μg of ascorbic acid in 3 ml of phosphate buffer. The record of current response to substrate addition lasts 1-2 min. The ascorbic acid values determined in various samples of fruit juices are in good agreement with the data obtained by titration and polarography. The suitable composition of the membrane and its lifetime and stability during long-term storage are described; optimal reaction conditions of vitamin C determination and the possibilities of interference of other compounds are also examined. Of the 35 phenols, aromatic amines and acids tested chlorogenic acid only can cause a positive error provided that the enzyme membrane has been prepared from ascorbate oxidase of high purity.

scholarly journals Degradation Kinetic Modelling of Ascorbic Acid from Orange Juice

Proceedings ◽  
2020 ◽  
Vol 70 (1) ◽  
pp. 55
Author(s):  
Alina Soceanu ◽  
Nicoleta Matei ◽  
Simona Dobrinas ◽  
Viorica Popescu
Keyword(s):  
Ascorbic Acid ◽  
Vitamin C ◽  
Orange Juice ◽  
Storage Temperature ◽  
Kinetic Modelling ◽  
Activation Parameters ◽  
Graphical Analysis ◽  
State Theory ◽  
Activation Process ◽  
Degradation Kinetic

Vitamin C or ascorbic acid is a basic nutrient, a highly effective antioxidant, widely used as food additive. Therefore, quality control in food industry demands ascorbic acid determination methods. The purpose of this study was to determine vitamin C in natural orange juices by spectrometric and voltammetric methods. Another goal was to determine the kinetic and thermodynamics activation parameters for ascorbic acid degradation in orange juices over time and at different temperatures. It was observed that during storage, ascorbic acid concentrations in orange juices were gradually decreased with time at a rate depending on storage temperature and type of orange juice. The reaction order was determined through integrated graphical analysis where the dependences of ln ct/c0 as a function of time reveals the high values for R2, indicating that the kinetics of the degradation of AA follows first order reaction at both studied temperatures. For studied samples the loss of ascorbic acid was varied between 4.33% and 9.13%. Enthalpy variation (ΔH) and entropy variation (ΔS) of activation process were obtained from the Eyring–Polany model based on transition state theory. The values of activation energy ranged between 7289.24 kJmol−1 and 15689.54 kJmol−1.

scholarly journals Vitamin C in Human Health and Disease

Nutrients ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 1595
Author(s):  
Dariusz Nowak
Keyword(s):  
Eighteenth Century ◽  
Vitamin C ◽  
Human Health ◽  
Citrus Fruit ◽  
Ancient Egypt ◽  
Vitamin Supplement ◽  
Vitamin C Deficiency ◽  
Health And Disease

Although the symptoms related to vitamin C deficiency were known in ancient Egypt and eighteenth century Scottish surgeon James Lind found that scurvy (a disease resulting from insufficient dietary ingestion of vitamin C) could be effectively treated with citrus fruit, this vitamin was discovered only in the year 1912 and then after 21 years it was chemically synthetized and introduced to the market as the first vitamin supplement [...]

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