Abstract: A process for purifying lactulose from other carbohydrates, in particular from lactose and galactose, by passing a lactulose syrup through one or more columns containing a bifunctionalized boron resin of the type: ##STR1## in which .circle.P is a polyacrylic or polystyrene polymer matrix and R, R.sup.1, R.sup.2, R.sup.3, X are as defined in the text.By passing the lactulose solution containing carbohydrate impurities through a boron resin (I) of polyacrylic matrix, the lactulose is selectively retained and is subsequently released by elution with an acid solution.The small quantity of galactose which may still be contained in the lactulose-enriched solution can be removed by passing said solution through a boron resin (I) of polystyrene matrix, which selectively retains the galactose.

Abstract: Stable boron resins of high selective absorbent power and a relative production process; said boron resins are constituted by a polyacrylic matrix bifunctionalized with quaternary ammonium groups and with alkylphenylboric groups in accordance with general formula (I) ##STR1## in which P , R, R.sup.1, R.sup.2, R.sup.3, X are as defined in the text. The resin (I) is prepared by condensing an amino resin with halophenylboroxine or with haloalkylphenylboroxine.The resin of formula (I) can be used for purifying lactulose.