Clarification of sugarcane juice by hydrogen peroxide: effects of the presence of dextran

Summary

The quality of crystal sugar is directly associated with the quality of the sugarcane (Saccharum s.p.) delivered to the mills and to the efficiency of the industrial process. Dextran is considered to be a quality parameter of the raw material, since its presence indicates the sugarcane suffered deterioration between the cutting and processing steps. During processing of the juice, dextran can interfere in the process efficiency. In the clarification step, the main objective of sulphiting is to promote a reduction in the ICUMSA colour of the sugarcane juice. The ICUMSA colour is the most important parameter for the classification of commercial sugar in Brazil and the lower the ICUMSA colour the whiter the sugar. Hydrogen peroxide (H₂O₂) has been studied as a possible clarifying agent to replace sulphite in the clarification of sugarcane juice, since sulphite has some contraindications for human respiratory health. The objective of the present work was to determine the impact of the presence of dextran on the efficiency of the reduction in ICUMSA colour of sugarcane juice by peroxidation. During peroxidation, the temperature and pH significantly influenced the reduction in ICUMSA colour of the juice, increases in temperature, increases in the dose of hydrogen peroxide and decreases in the pH, all leading to decreases in ICUMSA colour. The values for dextran used (up to 1,000 ppm) showed no significant influence on the colour of sugarcane juice, however they showed significant interactions with other parameters.

Key words:
Saccharum officinarum L.; Advanced oxidation process; Colour; Peroxidation; Sucrose