Studies On Teasaponins' Extraction And Purification And Its Antibacterial Activities

The method of teasaponins'quantitative determination, and process of extraction, purification from cake of camellia oleifera have been studied in this dissertation, and teasaponins'antibacterial activities were studied preliminary.The spectrophotometric method of vanillin-concentrated sulphuric acid to measure the content of teasponins was established. The results show that: the maximum absorption wavelength of 520 nm, 8% of the vanillin ethanol solution, 4 ml of 77% concentrated sulphuric acid, water bath temperature of 60℃, bath time of 20 minutes. under the conditions of the best results, the relative standard deviation was 1.57%, and an average recovery rate was 99.26 percent. Through the tests of ruled out interference material, impurities in the method of water extraction can bring a greater impact on the result and impurities in the alcohol extraction can't affect the result on the whole, so the determination of teasaponins content was used in the alcohol extraction.The method of teasaponins'extraction technics from cake of camellia oleifera seed was studied. Through the contrast of three common methods of teasaponis'extraction, we determined using the method of ultrasound-assisted the alcohol-water extraction. The optimum conditions for the ultrasound-assisted the alcohol-water extraction were determined using response surface methodology (RSM). A central composite design was used to investigate the effects of four independent variables, the liquid to solid ratio, extraction temperature, extraction time and ultrasonic power on the response, content of teasaponins. Data were analyzed using SAS8.1 software. Typical of the response surface know stability is the maximum. The optimum conditions of the ultrasound-assisted the alcohol-water extraction were: the liquid to solid ratio 4.1:1, extraction temperature 80℃, extraction time 3.3h, ultrasonic power 725W, alcohol concentration 85%, 85% alcohol and concentrated liquid volume ratio 4:1, extraction temperature 75℃, extraction time 2h, teasaponins content 80.51%.At the same time, a new extraction method:water-fermentation process, and its impact on the factors were studied. The results show that the optimum extraction conditions were: liquid to solid ratio 4:1, extraction temperature 80℃, extraction time 4.5 h, add enzyme a 2.5‰, enzyme b 3.5‰, and the question of yeast fermentation liquid volume ratio 1:10.By contrast of water-fermentation and ultrasound-assisted the alcohol-water and water extraction method, water-fermentation extraction has a very substantial increase in the content of teasaponins and similar to the yield of teasaponins than water extraction ,that with ultrasound-assisted the alcohol-water the content of teasaponins in slightly lower, the yield has increased , But also product quality has to be improved.With the material of alcohol extraction teasaponins, the purification effects on tea saponin of macroreticular polymeric absorbent were studied. The results showed that AB-8 was the suitable resin of purifing tea saponin. The factors on the adsorption and desorption effects of AB-8 were studied and the showed that the optimal conditions were 34.4mg/ml for concentration of tea saponin of extraction solution, adsorption temperature 25℃,100 minutes for adsorption time,30℃for desorption temperature,80% for concentration of ethanol, 4:1 for ratio of ethanol to addition solution,80min for desorption time.The rate of tea saponin adsorption was 90.70%,the rate of tea saponin desorption was 85.47% and the content of teasaponins was 85%.E.coli, Staphylococcus aureus, Bacillus subtilis is the common bacteria in food production, processing, storage of corruption. Through the tea saponin inhibitory effect of the three strains of the study, it showed that the teasaponins has good inhibitory effect of the E.coli and tea saponin Bacillus subtilis,and has no inhibitory effect of Staphylococcus aureus.