Optimization of Ultrasonic Assisted Tea Saponin Extraction by Response Surface Design

The central composite design was used to optimize the ultrasonic assisted extraction of tea saponin from the Camellia oleifera dregs. A mathematical regression model was established between the yield and such extraction procedural factors as the pH value, extraction temperature, ultrasonic time, ratio of the liquid-material and ultrasonic power. Based on the model, the optimal conditions are as follows: 75% alcohol as the extraction solvent; extraction at 40℃ for 4h; the ratio of liquid to solid 8:1; the ultrasonic power 80W. Under the above optimal conditions, the average actual extraction yield of tea saponin will amount to 8.041 %(n =5), which was in close agreement with the value predicted.