Application of biocides in the process of sucrose extraction from sugar beet: Effect on sucrose content, number of Leuconostoc colonies and wet pulp characteristics

This research investigated the application of different extraction biocides in the sugar beet processing stages. The simulation of industrial processes of sugar beet extraction and beet pulp pressing is conducted using the laboratory-scale equipment. Statistical significance analysis of influence of input factors on observed responses is performed by response surface method (Box-Behnken design). Special interest was dedicated to the biocide influence on the wet pulp pressability characteristics. Multiple effects of application of chlorine dioxide on quality parameters of intermediates (diffusion juice sucrose content and number of Leuconostoc colonies, wet pulp pressability) are compared to the standard biocides used in sugar industry. Results indicate that the application of chlorine dioxide corresponded with the best pulp pressing characteristics with 5-15% more efficient mechanical dewatering of the wet pulp compared to the other samples, significantly affecting the potential energy consumption. The use of chlorine dioxide lowered the potential energy consumption in the range from 168 to 335 MJ per tonne of wet pulp. All the biocides used in this study showed remarkable biocide effectiveness against mesophilic bacteria Leuconostoc mesenteroides reducing the number of colonies in the range from 82 to 99%.