Thermal treatment of technical sucrose solutions of beet and cane origin

In: Sugar industry, S. 406-413

Abstract

In the production of sugar from mixed syrups containing feedstock from beet and cane origin the non-sugar fraction plays an equally important role as in processing of material from a single source. However, the consequences of the resulting mixed non-sugar fraction on processes such as impurity, mainly colorants, incorporation and chemical reactions have not been studied yet. In this contribution the results of a study elucidating the kinetics of colorants formation in mixed syrups on thermal stress are given. It is found that the relative increase of syrup color value with respect to the starting value behaves quite systematic for wide range of mixed syrups. In all syrups the color values increase linearly with exposure time. The rate of increase is the highest for beet syrups. The generation rate increases with temperature in line with Arrhenius' law. Different to earlier work no promoting effect of increased dry matter contents could be found. Furthermore, a model, assuming a first order reaction, to predict the color generation in mixed syrups based on the information of the pure syrups was formulated. This model is in essence generating data that match the experimental data within the range of the accuracy of the color value determination method. In conclusion the data suggest that there is no excess color generation on thermal stress due mixing of the non-sugar materials from different sources.