Optimization of the main liming process for inulin crude extract from Jerusalem artichoke tubers

A three-stage homogenate extraction was used as a new method for inulin extraction from Jerusalem artichoke tubers. Compared with the results from conventional hot water extraction, the three-stage homogenate extraction gave higher yields and caused less degradation of the inulin. The inulin crude extract was then clarified by a carbonate-precipitation method, during which three variables — the quicklime mass, the reaction temperature and the reaction time were optimized for the main liming process to give the best clarification effect. A Plackett-Burman design, the path of steepest ascent method, a Box-Behnken design and response surface methodology (RSM) were employed in the experimental design. The optimal conditions for the main liming process were determined to be 12.0 g/L, 71.4°C and 8 min. The confirmatory tests proved that the best clarification efficiency (92.74%) was achieved at these conditions and this was approximately equal to the value predicted by the model.