Investigation of terms for application of surface active substances in the manufacture of crystalline glucose
The successful outcome of the existing methods for the crystallization of glucose to greatly depends on the conditions of the stage of nucleation of crystals. The study was conducted with the aim to improve ways of nucleation during the crystallization of glucose. According to the theory of crystallization the rate of nucleation formation in the highest degree depends on the surface tension (ST) of solutions. Theoretical and practical interest is presented the role of ST in the process of crystallization of glucose. Studies have been carried out to determine the surface tension of glucose solutions depending on the concentration of dry substances (DS) and temperature. As a result of research, it has been determined that the ST of glucose solutions increases with an increase in the concentration of DS and a decrease in temperature. When testing aliphatic alcohols as a surface-active substances (surfactants), it was found that ST solutions decrease 2.5 times. The accelerating effect of aliphatic alcohols on the nucleation of crystals was expressed in a decrease in the induction period from 210 minutes to 120 minutes, respectively, in pure solutions and in the presence of surfactants. Tests of various types of seed crystals have revealed that large (> 200 μm) and small (<60 μm) hydrated glucose crystals moistened with alcohol are most effective for crystallizing anhydride glucose under polythermal conditions. The proposed method can significantly save the consumption of glucose for seed, improve the conditions of crystallization and improve the quality of glucose microbial purity.