Use of Response Surface Methodology for Optimization of Ultrasound-assisted Extraction of Total Saponins from Asparagus officinalis L.

Response surface methodology based on a three-variable,three-level Box-Behnken experimental design was used to optimize ultrasound-assisted extraction of total saponins from Asparagus officinalis L.The extraction yield of total saponins was investigated with respect to temperature,extraction time and ultrasonic power.The optimal extraction conditions were found to be: ethanol concentration 95%,temperature 71 ℃,extraction time 23 min,ultrasound power 70 W,and number of extractions 2.Under these conditions,the extraction yield of total saponins was 23.96 mg/g.