PURPOSE: To inexpensively obtain the title syrup useful as a multiplying agent for Lactobacillus bifidus by subjecting lactose to iosmerization reaction with an alkali and purifying a lactulose-containing reaction solution with a strongly acidic cation exchange resin having fixed degree of crosslinking.
CONSTITUTION: First, lactose, preferably 40-60wt.% aqueous solution of lactose is subjected to alkali isomerization reaction by a method of adding 1-30wt.% based on lactose of caustic soda and heating ≥60°C and the isomerization reaction is stopped by a method of passing the reaction solution through a cation exchange resin to remove an alkali. Then a lactulose-containing reaction solution obtained by the procedure is purified by a strongly acidic cation exchange resin (preferably resin of alkaline earth metal type prepared by introducing SO to styrene-divinylbenzene copolymer as carrier) having fixed degree of crosslinking for chromatography to give the aimed syrup.
TAKAHASHI TAKESHI
IKEUCHI YOSHIHIRO
