Impact of Dextran Biodegradation Catalyzed by Dextranase Enzyme on the Crystallization Rate of Sucrose during Sugar Manufacturing

Abstract

Introduction: In this research work, we investigated the influence of the biodegradation of dextran catalyzed by dextranase enzymes during sugar manufacturing on the rate of sucrose crystallization and growth rate of sucrose crystals in pure sucrose solution at different temperatures. Methods: To elucidate the influence of biodegradation of dextran on the growth rate of sucrose crystals, dextran of Mw 2,000,000 g/mol (T2000) was admixed in concentrations between (1000 - 10000 ppm) with (60% -75% w/w) sucrose solution.. The hydrolysis of dextran was carried out at 55.0 °C and pH 5.5 at different dextranase concentration, and then the samples were immediately subjected to the crystallization process. Results: The most pronounced effect of dextran on the growth rate of sucrose crystals was found with T2000 at concentrations more than 5000 ppm at 60°C. From the results it could be shown that an increase of crystallization rate of up to 50% after biodegradation of dextran T2000 using dextranase enzyme at concentration of 100 ppm, compared to crystallization rate with pure sucrose solution in the presence of dextran T2000. It was obvious that after dextran hydrolyzed by dextranase, more perfect crystal surfaces are built than at 60°C. Conclusion: Dextran biodegradation catalyzed by dextranase enzyme has increased the crystallization rate of sucrose and more perfect crystal surfaces are built. Such a positive influence of biodegradation of dextran using dextranase enzyme decreases crystallization time in the sugar house and thus decreases the production costs of sugar manufacturing.