Processing Challenges and Financial Impacts of Dextran in Cane Sugar Production: A Review

Abstract

Dextran is one of the most significant impurities present in sugar production. It is synthesized by contaminant microorganisms from sucrose. The presence of dextran in the canesugar factories and refineries leads to a falsely high polarization, increased viscosity, slowing of filtration, lower evaporation rates, however, from the processing point of view, the most damaging effects of elevated dextran concentrations in a technical sucrose solution are foreseen in the crystallization process. Dextrans slow down the crystallization rate or even inhibit crystallization. All these possessing difficulties caused by dextrans lead, in the end, to the sugar losses and these economic losses are continuous throughout the process. To date, the use of the dextranase enzyme is the most efficient method for hydrolyzing the dextran at canesugar factories and refineries. The fungal dextranases showed the highest reaction rate at low °Brix, with pH and temperature close to 5.0 and 50ºC, respectively, that is, conditions existing in juice extraction. Dextranase also can be added to syrups and evaporator bodies, however, to reach a satisfactory level of dextran hydrolysis, it is necessary to correct the dose of dextranase enzyme according to the losses of activity caused by the high °Brix. The enzymatic hydrolysis of dextranase in sugar industry can have a positive financial impact by increasing the efficiency of sugar production, improving the quality of the final product, and reducing operational costs associated with dextran buildup. Immobilization and recombinant enzyme technology are the most promising technologies for improving the industrial efficiency of dextranases in sugar industry. A novel promising method to improve the biodegradation an immobilization parameter of dextranase enzymes was developed using the synergistic effects of ultrasound combined with microwave shock as new green technologies. However, this technology also has not been commercialized yet.