Physical and chemical properties
Activity of vitamin C are generally destroyed by heat treatment of food, especially when there are traces of metals such as copper, but it is resistant to freezing. Vitamin C is probably one of the most unstable among the vitamins soluble in water. In nature there are only L-form of ascorbic and dehydroascorbic acid.
Vitamin C is very soluble in water and methanol, and about five times lower in ethanol. Ascorbic acid is well oxidized by air oxygen, especially in the presence of heavy metal ions (such as: copper, iron, etc.).
In the absence of oxygen, ascorbic acid can withstand heat up to 100°C.