Reivindicaciones

1. Use of β-D-galactopyranosyl-D-xyloses for the preparation of compositions and solutions intended to the evaluation of intestinal lactase, characterized in that - the β-D-galactopyranosyl-D-xyloses present several hydroxyl groups adjacent respectively to the glycosidic bond in its molecule. 2. Use according to claim 1, characterized in that the β-D-galactopyranosyl-D-xyloses are selected from among the 2-O-β-D-galactopyranosyl-D-xylose, 3-O- β-D-galactopyranosyl-D-xylose and mixtures of the same. 3. Use according to claim 1 or 2, characterized in that the compositions comprise pharmaceutically acceptable quantites of at least one additive selected from among stabilizers, protectors, taste enhances, lactose , gels, fluxants and conservatives. 4. Use according to any of the claims 1 or 2, characterized in that the solutions are aqueous. 5. Use according to claim 4, characterized in that the solutions are saline. 6. Use according to any of the claims 1, 2, 4 or 5, characterized in that the solutions comprise pharmaceutically acceptable quantities of at least one additive selected from among stabilizers, protectors, taste enhances, lactose and conservatives. 7. Enzymatic procedure for the preparation of β-D-galactopyranosyl-D-xyloses, which comprises at least one β-D-galactopyranosyl-D-xylose which presents several hydroxyl groups adjacent respectively to the glycosidic bond in its molecule, characterized in that it comprises: (a) reactivating a D-xylose and a β-D-galactopyranoside substrate in the presence of a β-galactosidase enzyme, to a concentration of D-xylose / β-D-galactopyranoside substrate of 2-20:1, in an aqueous medium buffered to a pH between 5,0 and 9,0 and at a temperature between 4 and 37°C ; (b) deactivating the β-galactosidase enzyme by heating at 100°C when reaching the maximum yield of formation of disaccharides, based on thin layer chromatography; (c) isolating the disaccharides formed through filtration in a packed column with a thinner selected between water and mixtures of water and alcohol. 8. Procedure according to claim 7, characterized in that the β-D-galactpyranoside substrate is Ó-nitrophenyl β-D-galactpyranoside. 9. Procedure according to claim 7, characterized in that the β-D-galactopyrandoside is substrate lactose. 10. Procedure according to claim 7, characterized in that the β-galactosidase enzyme is β-D-galactosidase of E. Coli . 11. procedure according to claim 7, characterized in that it is conducted in the presence of at least one cosolvent, miscible with water. 12. Procedure according to claim 11, characterized in that the cosolvent is selected from among at least acetonitrile, dimethyl formamide, dimethyl sulfoxide and mixture of the same. 13. Procedure according to claim 7, characterized in that the packed columns are packed with one of Sephadex G-10 and Biogel P-2. 14. Procedure according to claim 7, characterized in that the packed columns are packed with active carbon. 15. Procedure according to claim 7 or 10, characterized in that the formed disaccharides are a mixture of 2-O-β-D-galactopyranosyl-D-xylose, 3-O-β-D-galactopyranosyl-D-xylose and 4-O-β-D-galactopyranosyl-D-xylose. 16. Procedure of claim 10, characterized in that from the formed disaccharides, at least one of the 2-O-β-D-galactopyranosyl-D-xylose, 3-O-β-D-galactopyranosyl-D-xylose, is isolated.