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

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.

1987 ◽  
Vol 67 (1) ◽  
pp. 331-335
Author(s):  
HAK-YOON JU ◽  
W. JOHN MULLIN

The ascorbic acid (vitamin C) content of fresh imported field tomatoes and Nova Scotia greenhouse and field tomatoes was determined on a bi-weekly basis during the period of availability of each type of tomato to the Nova Scotia consumer in 1984. The average ascorbic acid contents of imported and Nova Scotia field and greenhouse tomatoes were 13.3, 16.7 and 17.7 mg 100 g−1 fresh weight, respectively. A study of nine recommended or promising field tomatoes for the Atlantic region showed significant differences in ascorbic acid content among the cultivars. The cultivar Quick Pick had the highest ascorbic acid content of 22.5 ± 1.5 mg 100 g−1, the cultivar Campbell 18 had the lowest content, 12.0 ± 2.9 mg 100 g−1. In Dombito greenhouse tomatoes the stage of maturity and the effect of cluster location were tested against ascorbic acid content. The lowest ascorbic acid content of 9.1 ± 1.0 mg 100 g−1 was found with the small green tomatoes while others from mature green to overripe contained 14.0–16.7 mg 100 g−1. Tomatoes from different cluster locations showed no significant difference in ascorbic acid content.Key words: Vitamin C, L-ascorbic acid, tomatoes


2003 ◽  
Vol 3 (1) ◽  
pp. 5-13 ◽  
Author(s):  
Khalid Iqbal . ◽  
Alam Khan . ◽  
M. Muzaffar Ali Khan .

1936 ◽  
Vol 11 (5) ◽  
pp. 425-432 ◽  
Author(s):  
Russel Rasmussen ◽  
N. B. Guerrant ◽  
A. O. Shaw ◽  
R. C. Welch ◽  
S. I. Bechdel

Scientifica ◽  
2013 ◽  
Vol 2013 ◽  
pp. 1-24 ◽  
Author(s):  
Daniel R. Gallie

L-Ascorbic acid (vitamin C) is as essential to plants as it is to animals. Ascorbic acid functions as a major redox buffer and as a cofactor for enzymes involved in regulating photosynthesis, hormone biosynthesis, and regenerating other antioxidants. Ascorbic acid regulates cell division and growth and is involved in signal transduction. In contrast to the single pathway responsible for ascorbic acid biosynthesis in animals, plants use multiple pathways to synthesize ascorbic acid, perhaps reflecting the importance of this molecule to plant health. Given the importance of ascorbic acid to human nutrition, several technologies have been developed to increase the ascorbic acid content of plants through the manipulation of biosynthetic or recycling pathways. This paper provides an overview of these approaches as well as the consequences that changes in ascorbic acid content have on plant growth and function. Discussed is the capacity of plants to tolerate changes in ascorbic acid content. The many functions that ascorbic acid serves in plants, however, will require highly targeted approaches to improve their nutritional quality without compromising their health.


Author(s):  
O. A. Grebennikova ◽  
V. A. Melnikov

The results of the ascorbic acid content in the fruits and leaves of 10 persimmon cultivars from the Nikitsky Botanical Gardens’ collection are presented. It has been established that the concentration of ascorbic acid in technical persimmon fruits is 19,8-56,3 mg / 100 g, and in mature fruits it is 70-85% lower (5,08-8,96 mg / 100 g). Persimmon leaves contain 5-20 times more ascorbic acid than in fruits. The results showed the ability to use persimmon leaves as an additional source of vitamin C. The maximum content of ascorbic acid is allocated to the fruits of the cultivars Virginskaya Krupnoplodnaya, Delishes, Sidles and leaves of the cultivars Sidles and Zolotistaya.


Author(s):  
Hoda Ashari ◽  
Naficeh Sadeghi ◽  
Mohammad Reza Oveisi ◽  
Mannan Hajimahmoodi

This study was designed to measure and compare the total phenols, flavonoids and vitamin C contents in four orange juice brands which are commercially available in Iran. Total phenols, flavonoids and ascorbic acid content of 100 samples from four different commercial brands were evaluated by the spectrometric method. The concentration of total phenol in commercial orange juice samples was between 28.39 and 114.20 mg gallic acid equivalent per liter (mg GAE/L). The measured range of total flavonoids was from 12.53 to 32.62 mg quercetin equivalent per liter (mg QE/L) and the content of ascorbic acid in the samples was between 29.95 and 93.08 mg/L. The results showed a significant difference between the four brand`s total phenols, flavonoids and vitamin C level (P< 0.05). According to the found variation among different studied brands, setting a determined amount for the measured parameters is suggested.


2017 ◽  
Vol 51 (04) ◽  
Author(s):  
M. Prabhu ◽  
S. Parthiban ◽  
A. Ramesh Kumar ◽  
B. Usha Rani ◽  
A. Jayasamundeeswari

India is the largest producer of acid lime in the world and they are used as fresh fruit or for the preparation of pickles and beverages. They are rich in vitamin C, minerals and salts. The seasonality of production leads to market glut which results in poor returns to the farmers. Hence, an experiment was conducted to manipulate and regulate flowering by using various plant growth regulators viz., GA­3 and cycocel, chemicals viz., KNO3 and salicylic acid at 11 different treatment combinations. The experiment was conducted in randomized block design (RBD) and each treatment was replicated thrice. The age of the trees was seven years and the variety used was PKM1. The experiment conducted in four consecutive years. The experimental results showed that there were significant differences among the treatments. Acid lime trees sprayed with GA3 50 ppm in June + cycocel 1000 ppm in September + KNO3 2% in October recorded the highest number of fruits tree-1 (1003), weight of fruits (48.60 g) and average fruit yield (28.96 kg tree-1). The same treatment registered the highest values for juice content (32.13 %), TSS (7.29o Brix) and ascorbic acid content (32.56 mg / 100ml).


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