Brown, beige and dolomitic (white) sepiolites from the area around Ankara-Polath-Turktaciri iri village were tested for the decolorization of sugar solutions at different pH and temperature. The decolorizing effect of various quaternary ammonium salts in combination with the sepiolites was also investigated. The sepiolites were characterized by its zeta potential, filtration capacity, particle size and specific surface area. Before and after the treatment of sepiolite with the sugar juice, the sepiolites were investigated by DTA/TG and SEM. The brown sepiolite had a more developed fiber structure, smaller particle size when dispersed in water, a larger surface area and a greater decolorizing activity than the other samples. Addition of small quantities of quaternary ammonium salts to the brown sepiolite improved the removal of sugar juice color by up to 80%. (C) 1998 Elsevier Science B.V.