Abstract
It has been known that the dextran aqueous solution of high concentrations turns into a gelatinised state in the presence of highly-concentrated potassium ions, and that it is not gelatinised in the absence of potassium ions, or when their concentration is low. From the present study, It was found that the dextran-KCl aqueous solution, the concentration of which is not so high for both of dextran and KC1, turns into a gelatinised state as a result of the freeze-concentration. However, gelatinisation was reversible: the system gelatinised by the freeze-concentration treatment returned to the original solution state when it was kept at ambient temperatures.