Abstract: A liquid starch solution suitable for saccharification into a maltose-containing product is obtained by suspending starch in water, adding to the starch suspension a heat resistant .alpha.-amylase and a buffer, adjusting the resultant mixture to a pH value in the range of from 7.5 to 8.0, and thermally treating the resultant starch milk while repressing possible hydrolysis of starch molecules.

Abstract: From a maltose solution of a purity of 75 to 90%, a high-purity maltose solution having a maltose purity of more than 98.5% is obtained in a high yield by preparatorily treating activated carbon with the aqueous solution of an organic solvent, adding the same organic solvent to the maltose solution under treatment until the concentration of the organic solvent equals that in the aqueous solution used for the treatment of the activated carbon, and subsequently bringing the resultant solution into contact with the activated carbon for thereby allowing the activated carbon to adsorb selectively out of the solution only the saccharides such as maltotriose and maltotetraose which are composed of three or more glucoses.

Abstract: A method for the recovery of refined .alpha.-galactosidase is disclosed. This method comprises the steps of bringing an .alpha.-galactosidase-containing liquid into contact with a weakly acidic cation-exchange resin in the presence of a buffer solution for thereby allowing .alpha.-galactosidase to be selectively adsorbed by said resin, desorbing the adsorbed .alpha.-galactosidase from said resin by use of a buffer solution of a type such that at least one of the two factors, concentration and pH, has a higher value than that of the buffer solution used in said adsorption and thereafter recovering the desorbed .alpha.-galactosidase.