Influences of ethanol on the thermodynamics and kinetics in the crystallization of xylitol

The metastable zone and crystal growth rates of xylitol in water were investigated under the influence of small volume fractions of ethanol. The utilization of low amounts of ethanol is necessary to help adding slightly soluble ingredients during the fabrication of xylitol products, e.g. in food industry. Therefore, the metastable zone and crystal growth rates were determined by means of an ultrasound measurement technique and batch crystallization experiments. It can clearly be seen that the addition of ethanol is lowering the solubility of xylitol in water. The higher the volume fraction of ethanol, the lower the solubility. The metastable zone width is increased whereas the smallest investigated ethanol content results in the widest metastable zone. The crystal growth of xylitol is inhibited by the addition of ethanol whereby the crystal growth rates are decreasing with increasing ethanol content.