Shikimic acid can be rapidly separated (ca. 5 min) from Chinese star anise with hot water extraction at temperatures of 120 degrees C or higher to obtain recoveries of 100%. Extraction recoveries of shikimic acid close to 97% can be obtained with water at 70 degrees C using slightly longer extraction times (ca. 10 min) than those at 120 degrees C. A semi-batch flow apparatus was used to study the effect of temperature, average particle size, water flow rate, and extraction time on the experimental recoveries. For 0.5 g Chinese star anise raw material that contained ca. 8% shikimic acid, 100% recoveries of shikimic acid could be obtained with 60 g water at 150 degrees C at 15 MPa in 4 min for star anise material having a particle size range from 355 to 600 mu m. A one-site kinetic model was found to provide good correlation of the data and the kinetic parameters of the model could be written in terms of linearized contributions in temperature, average particle diameter and flow rate. (c) 2009 Elsevier B.V. All rights reserved.