Potassium Metabisulfite- Industrial / Technical Grade
Potassium metabisulphite is a white crystalline powder with a pungent sulfur odour. It is also known as potassium pyrosulfite. Its chemical formula is K2S2O5 and has monoclinic crystal structure which decomposes at 190 °C, yielding potassium oxide and sulfur dioxide:
K2S2O5(s) = K2O(s) + 2SO2(g)
It is mainly used as an antibrowning agent, antioxidant and preservative. It is a disulfite and is chemically very similar to Sodium Metabisulfite, with which it is sometimes used interchangeably.
Potassium metabisulphite is generally preferred out of the two as it does not contribute sodium to the diet. It is soluble in water and insoluble in ethanol.