Optimization of ultrasonic- assisted extraction of tea saponin using response surface methodology

Tea saponin was extracted by ultrasonic-assisted methanol extraction with defatted oil-tea camellia seed meal as raw material. With extraction rate of tea saponin as index,the extraction process was optimized by single factor experiment and response surface methodology. The optimal extraction process conditions were obtained as follows: methanol volume fraction 80%,methanol dosage 45 mL( 5 g defatted oil-tea camellia seed meal),ultrasonic time 30 min,ultrasonic frequency 25. 97 kHz,extraction time 1 h,extraction temperature 57 ℃. Under the optimal conditions,the purity and extraction rate of tea saponin with light yellow were 85% and 94. 28%,respectively.