E300 - L-ASCORBIC ACID
L-ascorbic acid (enantiomer better known as vitamin C) is a water-soluble antioxidant vitamin that has multiple functions in the body, and which is widely used as an additive in foods.
The story of ascorbic acid is linked to that of the disease called scurvy, a vitamin C deficiency disease demonstrated by James Lind in 1747 and published six years later.
Ascorbic acid is particularly contained (40-150 mg / 100 g of product) especially in citrus fruits, kiwis, berries, hot peppers, raw peppers, rocket, broccoli, Brussels sprouts, dog rose etc.
In plasma, 90-95% of the vitamin circulates as ascorbic acid and 5-10% as dehydroascorbic acid.
Vitamin C is stored in moderate quantities in the body's tissues, particularly in the adrenal gland and liver; however, not all of it is stored in the body and the excess is eliminated in the urine.
Ascorbic acid is a water-soluble, acidic compound that comes in the form of crystals. It is a vitamin that is quite affected by light, humidity and air; these factors should therefore always be monitored to avoid the loss of vitamin C in foods.
The food industry, for an economic reason, uses the natural-identical form; this vitamin is very soluble in both water and alcohol and is able to counteract the reaction between amines and nitrites, which leads to the formation of dangerous N-alkyl -nitrosamines In addition to this function, vitamin C is very useful in the maturation processes of flour.
Vitamin C, taken from the diet, is absorbed respectively in the mouth, stomach and above all in the small intestine, thanks to a process of passive diffusion dependent on sodium. It is a very efficient system and it is especially so for low concentrations of C vitamin.
The strong antioxidant action of vitamin C and its ability to keep vitamins A, E, folic acid and Thiamine (B2) stable, is exploited by industries (as such or in the form of sodium, potassium and calcium salt) as additive in various foods.
The salts of ascorbic acid are:
- E301 SODIUM L-ASCORBATE
- E302 L-ASCORBATO FOOTBALL
- E303 DIACETYL-5,6-L-ASCORBIC ACID
- E304 ASCORBILE PALMITATE → indicates an ESTER FORMED BY THE "UNION OF" ASCORBIC ACID WITH A FATTY ACID (PALMITIC OR STEARIC). It is used in oils (except olive oil) and in fats to avoid rancidity. It plays an "adjuvant action" of the antioxidant activity of natural tocopherols.
- POTASSIUM ASCORBATE has been removed from the list of EU approved additives.
Consuming high concentrations of vitamin C contributes to:
- to decrease uric acid levels, with a preventive effect against hyperuricemia (serum uric acid concentration> 6 mg / dl) and gout
- to increase the absorption of iron by reducing Fe (3+) to Fe (2+)
- to the synthesis of collagen in the body
- to the regenerating action of vitamin E by the transfer of an electron to the α-tocopheroxy radical.
- to protect the body with an antihistamine action
- to reduce the number of intestinal nitrosamines and various oxidizing compounds (superoxide radical, hypochlorous acid and hydroxyl radicals).
- to various chemical reactions indispensable for our organism among which remember the synthesis of carnitine, the hydroxylation of lysine and proline (for the synthesis of collagen) and the synthesis of bile acids.
A lack of vitamin C, as we said earlier, can lead to the appearance of scurvy, a disease that determines a reduced synthesis of collagen and intercellular cementing substance. This deficiency causes alterations in the blood vessels, with the consequent manifestation of hemorrhages (sometimes leading to a picture of iron deficiency anemia), slowing of wound healing, gingivitis with alterations of the dentin and osteoporosis of the bones. Stunted growth can also occur in children.
In addition to these pathologies, the insufficiency of vitamin C levels also seems to favor atherosclerosis due to oxidative stress (not opposed by the antioxidant action of this vitamin) and the collapse of blood vessels (due to lack or reduced synthesis of collagen in the blood walls).
DOSE RECOMMENDED BY LARN:
For the adult individual, the minimum quantity of vitamin C necessary to prevent the onset of scurvy is about 10 mg / day; however, it is recommended to consume a higher quantity than that indicated as the “minimum quantity”.
In Italy, a level of 60 mg / day for men and women is recommended, equal to that recommended in the American RDAs (National Research Council, 1989).
However, it is also necessary to pay attention to situations that differ from the physiological one.
For example, recent studies have shown that smokers have a double requirement for vitamin C due to the increased metabolic turnover of this vitamin (by more than 40%).
In the nurse, due to the amount of vitamin secreted with milk, the recommended and recommended levels should be higher (30 mg / day more). In addition to the nurse, even during pregnancy it is estimated that the daily requirement increases by about 10 mg.
In the case of infants, the recommended amounts are based on the vitamin C content of breast milk, and are set at about half of those recommended for adults (20-30 mg / day).
For later ages, however, the recommended doses are gradually increased with increasing body weight, until reaching those of adulthood.
Ascorbic acid is harmless in small doses (usual doses), but if you consume it in too high doses (> 10 g per day) you could get diarrhea and / or kidney stones.
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