Folic acid has the following important physico-chemical properties:
a) It is a yellow, spear-shaped crystalline substance.
b) The compound is sparingly soluble in water.
c) It is stable in acid solution but when heated in alkali, it is readily destroyed.
d) The vitamin can withstand a temperature of 120°C for 30 minutes at neutral pH but at pH 1.0, folic acid loses about 70-100% of its activity when autoclaved at 120°C for 30 minutes.
e) Riboflavin accelerates the photo-oxidation of folic acid.