Abstract: Process for the preparation of lactulose wherein an aqueous solution or suspension of lactose is reacted with sodium aluminate in order to produce the isomerization of lactose and the mixture thus obtained is neutralized by treatment with gaseous CO2 under pressure, obtaining a suspension of aluminum hydroxide which can be easily separated from the lactulose solution.

Abstract: Stable boron resins of high selective absorbent power and their production process. Said boron resins consist of a polyacrylic matrix functionalized with quaternary ammonium groups, an epoxy group and phenylboric groups in accordance with general formula (I): ##STR1## in which P, R, R.sub.1, R.sub.2, R.sub.3, R.sub.4 and X.sup.- are as defined in the text. The resins are prepared by reacting an amine resin with an epihalohydrin and condensing the reaction product with a suitable boroxin. The resins of formula (I) can be used for separating sugars, in particular for purifying lactulose. They have greater selective power than currently known boron resins.

Abstract: A method for preparing high-purity crystalline lactulose and the product obtained by the method, which comprises crystallization from aqueous solutions at a temperature of 5.degree.-40.degree. C., the starting aqueous solution having a lactulose concentration of 50-80% w/w, a lactose concentration of less than 5% of the lactulose concentration by weight, a galactose concentration of less than 5% of the lactulose concentration by weight, and a concentration of other sugars of less than 4% of the lactulose concentration by weight.

Abstract: Stable boron resins of high selective absorbent power, their production process, and processes of using said boron resins. The boron resins include a polyacrylic matrix functionalized with quaternary ammonium groups, an epoxy group and phenylboric groups in accordance with general formula (I): ##STR1## in which P, R, R.sub.1, R.sub.2, R.sub.3, Y and X.sup.- are as defined in the text. The resin is prepared by condensing an acrylic resin with an epihalohydrin and then with a halide or hydroxide of an oxiphenyl-aminophenyl- or thiophenyl-boroxin or their alkyl derivatives. Compared with similar currently known resins, the resins of formula (I) have improved selectivity in sugar preparation. They can be used for purifying lactulose.

Abstract: A process for preparing high-purity lactulose by the following stages:(a) diluting with water to a concentration of 15-25% a syrup containing 45-55% of lactulose and having a lactulose content on a dry substance basis of between 74 and 82% w/w;(b) pretreating the diluted syrup with bromine or bifunctional boron resins;(c) treating the pretreated syrup from stage (b) with ion exchange resins of strong anion type under conditions such that the pH of the percolated syrup is between 8 and 10.

Abstract: A process for preparing lactulose from lactose in which an aqueous lactose mixture is reacted with a sodium aluminate solution and the solution obtained is continuously neutralized by feeding this solution and a sulphuric acid solution to a reactor simultaneously in such a manner as to obtain a pH of between 4.5 and 8.By operating in this manner an aluminium hydroxide suspension is obtained which can be easily separated from the lactulose solution.

Abstract: Stable boron resins of high selective absorbent power and their production process. Said boron resins consist of a polyacrylic matrix functionalized with quaternary groups, an epoxy group and phenylboric groups in accordance with general formula (I): ##STR1## in which P, R, R.sub.1, R.sub.2, R.sub.3, Y and X.sup.- are as defined in the text.The resin is prepared by condensing an acrylic resin with an epihalohydrin and then with a halide or hydroxide of an oxiphenyl-aminophenyl- or thiophenyl-boroxin or their alkyl derivatives.Compared with similar currently known resins, the resins of formula (I) have improved selectivity in sugar separation. They can be used for purifying lactulose.

Abstract: Stable boron resins of high selective absorbent power and their production process. Said boron resins consist of a polyacrylic matrix functionalized with quaternary ammonium groups, an epoxy group and phenylboric groups in accordance with general formula (I): ##STR1## in which P , R.sub.1, R.sub.2, R.sub.3, R.sub.4 and X.sup.- are as defined in the text.The resins are prepared by reacting an amine resin with an epihalohydrin and condensing the reaction product with a suitable boroxin.The resins of formula (I) can be used for separating sugars, in particular for purifying lactulose. They have greater selective power than currently known boron resins.

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: 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: 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 .circle.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.

Abstract: A process for preparing alpha-L-aspartyl-L-phenylalanine alkyl esters from L-aspartic acid, of which the amino group is protected by bonding it to a 3,5-dimethoxy-.alpha.,.alpha.-dimethyl-benzyloxycarbonyl group, then transforming this intermediate into the corresponding anhydride by means of a dehydrating agent, then reacting the anhydride with L-phenylalanine alkyl ester, and finally eliminating the protective group by the action of U.V. radiation.

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.

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.