Abstract: A process for purifying commercial lactulose in the form of syrup, comprising a first stage of chemical oxidation with bromine or electrochemical oxidation in the presence of sodium bromide, followed by treating the obtained aqueous solution with ion exchange resins in the following order:strong cationic resins of H.sup.+ formweak anionic resin of OH.sup.- formstrong anionic resin of bisulphite formstrong cationic resin of H.sup.+ formweak anionic resin of OH.sup.- form.

Abstract: A process for preparing lactulose from lactose, in the form of a concentrated syrup or high purity crystals, for pharmaceutical use or for use as a sweetener.The process is characterized by using as the lactose epimerizing agent a mixture of equal parts of MgO and sodium hydrosulphite, each component being used to the extent of between 0.05 and 0.2% by weight with respect to the lactulose, at a temperature of about 100.degree. C. The epimerization is complete in a few minutes.The crystalline lactulose is obtained by crystallization from ethanol.