The paper is focused on application of cross-flow ultrafiltration on ceramic membranes for refinement of starch hydrolysates. The use of membrane separation processes as a possibility for improvement of conventional filtration technologies is discussed as well. Samples of commercial hydrolysates from wheat starch obtained by acid and enzymatic hydrolysis were filtered on two different filtration units (T.I.A., Bollene, France and MUF, Mikropur, Czech Republic) equipped with various inorganic membranes (Membralox, TAMI). The mean pore size of used membranes was 20-100 nm. Properties of feed and permeate (i.e. viscosity, content of proteins, colour substances and sugar profile) were evaluated in dependence on membrane used. The results proved that ultrafiltration can fulfil some requirements especially for acid starch hydrolysate refinement, due to the removing of macromolecular substances, namely proteins and colour compounds, while the sugar composition and concentration is not affected. Achieved permeate fluxes (12-86 dm(3) h(-1) m(-2)) depend on the quality of syrup, i.e. on the technology, and on the tangential velocities which are different for both filtration units. (C) 2003 Elsevier Ltd. All rights reserved.