PURPOSE: To readily obtain the titled compound having multiplication promoting activity for Lactobacillus bifidus in high yield, by treating an aqueous solution of lactulose or aqueous solution containing the lactulose with β-galactosidase and carrying out galactose transformation reaction.
CONSTITUTION: Liquid or immobilized and purified or unpurified β-galactosidase is reacted with an aqueous solution of highly purified lactulose in 5W70wt.% lactulose concentration or an aqueous solution containing the lactulose as one constituent ingredient under condition of 20W50°C, 3W8pH and 0W0.5wt.% salts. After a given treating time, separation of the enzyme or inactivation thereof by heating is carried out to stop the enzymic reaction and afford the product solution of the aimed compound. The above-mentioned reaction solution is directly used or powdered by suitably concentrating or drying and, as neces sary, a purification step is applied to afford the final product.
TOMITA MAMORU
TOMIMURA TOSHIO
TAMURA YOSHITAKA
MIZOTA TERUHIKO
