Analysis of solute distribution in ice formed in progressive freeze-concentration

Abstract

Progressive freeze-concentration of 3 to 30% sucrose solutions were carried out using a small cylindrical apparatus. The solute concentration distribution in the ice phase was determined by cutting the ice formed into fractions and analyzing the solute concentration in the fractions. The solute concentration in the ice phase was found to increase as the concentration process progressed. From the solid phase analysis, the corresponding liquid phase concentration was estimated in the concentration process and an effective partition coefficient, K, was determined. K was also obtained from the concentration polarization theory. To this purpose, the limiting partition coefficient, K0, was obtained, then K was determined from the concentration polarization theory. K obtained by the two methods agreed well. K increased with an increase in solute concentration of sucrose, which corresponds to the higher incorporation rate of solute into the ice phase in progressive freeze-concentration.