The invention relates to a method for production of a preparation from a vegetable material, said preparation being enriched in a polysaccharide with a backbone comprising rhamnogalacturonan-I cores, said methodcomprising the steps:mixing the vegetable material with a polar alcoholic solvent and separating a solid residue obtained in step a) from the solvent and mixing the solid residue obtained in step b) with a buffered aqueous solution having a pH between 7 and 8.Also provided is a preparation containing rhamnogalacturonan-I pectins that can be obtained by this method and the use of such a preparation to modulate immune response.
