Purification of Tea Saponins and Evaluation of its Effect on Alcohol Dehydrogenase Activity

Tea saponins, extracted from a Camellia oleifera cake, were found to have a potent effect on de-alcoholic activity. To obtain highly pure tea saponins, which can better maintain the activity of alcohol dehydrogenase (ADH), this paper presents an extraction method for tea saponins using deionized water as the extraction agent and a two-stage precipitation method, including ethanol precipitation and CaO precipitation. The optimum conditions for ethanol precipitation were 95% alcohol, a duration of 1.5h and a solid/liquid ratio of 1:4; while the optimum conditions for CaO precipitation were a duration of 2h and an NH₄HCO₃/CaO ratio of 2:1. Under the optimum conditions, the content of saponins was 87.58%. The results showed that the greater the amount of tea saponins and the higher its purity, the more significant its activating effect on ADH. When the purity of tea saponins was above 75%, it activated ADH. It indicated that the de-alcoholic mechanism of tea saponins is associated with the activity of ADH. Furthermore, the study characterized the structure of tea saponins by UV absorption and Fourier Transform Infrared (FTIR) spectrometry and LC-MS.