Abstract <p>The influence of chemical modification on the sorption properties of apple pectin in relation to Mn²⁺ ions was studied. Pectin was modified with aromatic amino acids (L-histidine, L-tryptophan, L-phenylalanine) in an aqueous medium at pH 7. An increase in the extraction efficiency (by 12.6–21.4%) of Mn²⁺ ions of modified pectin sorbents was detected compared to the original polysaccharide, which is due to changes in their physicochemical characteristics and the appearance of new sorption centers in the structure. The values of thermodynamic parameters indicate the occurrence of a chemical adsorption process (∆<i>H</i>° =&#xa0;–42.6 to –24.3 kJ/mol). It is shown that sorption on modified pectins is best described by the Langmuir isotherm.</p>