Abstract: The effects of turbulence in the bulk solution, the dosage of ice crystal seed and the coolant temperature on the partition behavior between ice crystal and bulk solution during the freeze concentration of xylo-oligosacchrides were investigated. It showed that the observed partition coefficient decreases with increase in turbulence of the bulk solution during ripeness of ice crystal. The observed partition coefficient at the stirring rate of 500 r/min is only one tenth of 100 r/min, therefore, the more turbulent the bulk solutions, the higher the selectivity. The dosage of ice crystal seed has no effect on the observed partition coefficient. The observed partition coefficient at the coolant temperature of -0.5 ℃ is the same as one at -1.5 ℃, but the observed partition coefficient increases twice when the coolant temperature is reduced from -1.5 ℃ to -3.0 ℃.

Key words: xylo-oligosaccharides, freeze concentration, observed partition coefficient