List of fruits containing vitamin C (per100g)
Ziziphus jujuba (900 mg)
Jujube (fresh) (243 mg)
3. Seabuckthorn (204 mg)
4. Oranges (80 mg)
5. Kiwifruit (62 mg)
6. Hawthorn (53 mg)
7. Strawberries (47 mg)
8. Papaya (43 mg)
9.? Longan (43 mg)
10.? Litchi (4 1 mg)
1 1. grapefruit (38 mg)
12. Kumquat (35 mg)
13. cherry tomato (33 mg)
14. Orange (33 mg)
15. Spinach (32 mg)
The structure of vitamin C is similar to glucose, and it is a polyhydroxy compound. Two adjacent enolic hydroxyl groups in the second and third positions of its molecule are easily dissociated to release H+, so it has the nature of acid, also known as ascorbic acid.
Vitamin C has strong reducibility and can be easily oxidized to dehydrovitamin C, but its reaction is reversible, and ascorbic acid and dehydroascorbic acid have the same physiological function. However, if dehydroascorbic acid continues to be oxidized to generate diketonate, the reaction will be irreversible and completely lose its physiological efficacy.
Vitamin C is necessary for the formation of antibodies and collagen, tissue repair (including some redox actions), the metabolism of phenylalanine, tyrosine and folic acid, the utilization of iron and carbohydrates, the synthesis of fat and protein, the maintenance of immune function, hydroxylation and serotonin, the maintenance of vascular integrity, the promotion of non-heme iron absorption, etc. At the same time, vitamin C also has the functions of antioxidation, anti-free radical and inhibition of tyrosinase formation, thus achieving the effects of whitening and lightening spots.
In human body, vitamin C is a highly effective antioxidant, which is used to reduce the oxidative stress of ascorbate peroxidase substrate. There are many important biosynthetic processes that also need vitamin C.
Because most mammals can synthesize vitamin C by liver, there is no problem of deficiency. However, a few animals, such as humans, primates and groundhogs, cannot synthesize by themselves, and must be ingested through food and drugs.
References:
Vitamin C_ Baidu Encyclopedia