This work reports a process optimization study to obtain a concentrated solution of inulin from chicory roots. The crude inulin extract was obtained from a hot water extraction process followed by concentration under reduced pressure to a soluble solids concentration of 24 degrees Brix. The concentrated inulin solution was then submitted to a lowering of the temperature followed by centrifugation for phase separation, to obtain a more concentrated solution. The results of the precipitated mass rate (by weight) as well as the soluble solids concentration (degrees Brix) were evaluated by means of three variables - precipitation temperature, centrifugation velocity and centrifugation time interval. A central composite experimental design with five variation levels was used and response surface methodology applied for the data analysis. The statistical analysis of the results showed that only the factor temperature affected the mass precipitation rate. However, the soluble solids concentration suffered the influence of all three variables studied. (c) 2006 Elsevier Ltd. All rights reserved.