Abstract: Objective To study the technology of extracting geniposide from Gardenia jasminoides Ellis by ultrasound extraction. Methods Based on the single-factor experiments, a four-factor-three-level experiment design was developed by Box-Behnken central composite design method. Multi-quadratic equation was established with the yield of geniposide as response values. Results The optimum extraction condition was obtained as follows: ultrasound power 750.87 W, extraction time 46.57 min, ethanol concentration 52.06 % and ethanol volume(ratio of solvent to solid) 1:64.09 g·mL-1. The predictive maximum extraction yield was 36.16 mg·g-1 while the average experimental value was 35.49 mg·g-1, with the relative error of 1.85%. Conclusion The method is reliable, and can be used for industrial production.

Key words: geniposide, ultrasound extraction, response surface methodology