Application of response surface methodology to optimise the extraction of tea saponin from Camellia oleifera, and their verification by HPLC

Single factor combined with response surface methodology was used to optimise the process parameters of tea saponin extraction from Camellia oleifera. Four factors including material-liquid ratio, extraction temperature, extraction time, and ethanol concentration were selected as the influencing factors on the basis of single factor. The extraction rate of tea saponin was used as the response factor to analyse the response of these four factors and three levels. Results showed that extraction temperature of 81.69°C, material-liquid ratio of 1:11.85 g/mL, time of 6.17 h, and ethanol concentration of 56.69% were the best extraction conditions. The estimated yield of extraction was 7.46%. Analysis of the tea saponin samples by using high performance liquid chromatography showed that the main peak time was 6.668 min, and the absorption peaks and peaks were symmetric.