Use of Sulphitation in Sugar Making Process

The process of the sugar factories has improved from an archaic process called Khandsari. In India the Sugar was produced in the Khandsari units and the produce was a yellowish color powder. In the mid of the 20th century this traditional Khandsari was replaced partially by Open Pan Sulphitation (OPS) which is actually using the Sulphur compounds (commonly Sulphur Dioxide -SO2) to control the  pH, bacteria and color of the Sugar.

The SO2 in aqueous solution reacts with water to form H2SO3 (Sulphurous Acid) and thus more acidic solution is formed. It not only serves as a biocide but also gives crystalline and white sugar.

The reaction of SO2 with the carboxyl group of the Glucose and Fructose stops them to react with the amino acids (called Maillard Reaction which is used in preparing food flavors). Most factories burn the Sulphur to get SO2. The improved technique is Vaccum Pan Sulphitation (VPS) which is now used in most Modern Sugar Factories.