Gynura divaricata polysaccharide was extracted from Gynura divaricata with the method of microwave-assisted extraction. Based on the results of single factor experiments, the extraction process was optimized by response surface analysis. The results indicated that the influencing factors during extraction were: liquid-solid ratio, microwave time, and microwave power, among which the influence of liquid-solid ratio was the most significant. The optimal conditions were as follows: liquid-solid ratio of 45∶1(mL/g), microwave power of 390 W, microwave time of 22 min. Under optimal extraction conditions, the extraction rate of Gynura divaricata polysaccharide was 15. 36%, which was pretty close to the predicted result. The optimized response surface methodology had some practical value for the process.

Objective: To experimentally research the supercritical carbon dioxide extraction of ? carotene in spirulina powder. Methods: Inspected the effect of such different condition as pressure (10～50MPa), temperature (20～50 ?C ) and flow rate of carbon dioxide (10～35kg/h) on the extract process. Results: The extraction yield was increased with increasing the pressure and temperature. Conclusion: The optimum operating condition of supercritical CO 2 extraction were as follows: pressure 25～35MPa and temperature 20～40 ?C and flow rate of CO 2 20～25kg/h.