ICUMSA colour reduction in concentrated raw sugar solutions by an oxidative process with hydrogen peroxide

Abstract

Currently, the clarification/purification of refined sugar as from raw sugars such as very high polarization (VHP) is carried out using ion exchange resins or activated carbon. However, these are costly methodologies, which require constant regeneration/recovery and exhibit a loss of their ability as a function of processing time. Hence studies on alternative technologies to the use of ion-exchange resins and activated carbon are being increasingly reported to increase the economy of the sector. A commercial solution (35% v/v) of hydrogen peroxide can also be understood as an ICUMSA colour reducing promoter in the refined sugar production chain. Thus treatments were carried out to test the efficiency of the oxidizing agent in the clarification of type VHP raw sugar. The treatments were evaluated using different doses of hydrogen peroxide, and different pH values and temperatures for a reaction time of one hour. All the treated samples showed a reduction in the ICUMSA colour, the greatest decrease being in the range from 67 to 70%. The increase in dose of oxidizing agent was proportional to the increase in precipitates in the medium, the treatment with the highest hydrogen peroxide concentration showing turbidity of 142 NTU as compared to the value of the crude sample of 17 NTU, and was the assay with the greatest turbidity. Sucrose degradation was more pronounced in treatments below pH 5.0. Thus hydrogen peroxide was shown to be a viable alternative to reduce ICUMSA colour and precipitate non-sugars and the treatments with better colour reduction were also not critical with respect to sucrose degradation.

Keywords:
Clarification; Oxidation; Sucrose