The Research On The Extraction And Purification Technology Of Tea Oil And High Purity Tea Saponin From The Camellia Cakes

Southern China including Guangxi province is rich in Camellia oleiferaAbel. There are many active substances in Camellia Cakes which are extracted of oil after the oil press, such as residual tea oil, tea saponin, polysaccharides, flavonoids, and so on. But the lack of adequate long-term using can result in waste of resources, and even causes some environmental pollution. In this paper, we extracted tea oil and high-purity tea saponin from the camellia cakes and their utilization can alleviate environmental pressure, which has good economic and social value.In this thesis, using petroleum ether as solvent extractant and by viture of the different natures of tea oil and tea saponin, the two substances can be extracted from the camellia cake in turn——first tea oil, then tea saponin. Comprehensive utilization of dry tea, the study made the following conclusions:1. The investigation of extraction process of tea oil from the camellia cake. Firstly, the camellia cake was smashed and dried. Then using petroleum ether as extraction solvent, the influences of reaction conditions such as extraction times, extraction temperature, stock ratio and extraction time on the yield of tea oil were studied in details. At last, through orthogonal test L₉ (3⁴), the best extraction process was obtained. The results were as follows: under the conditions of extraction time 20min, extraction temperature 50℃and stock ratio of 1:6 (g/ml), the output of tea oil was 7.85 percent, its color is yellow, having a good odor.2. With GC-MS analysis, we found that main components of the extracted tea oil were hexadecanoic acid (palmitic acid), octadecadienoic acid (linoleic acid), octadecenoic acid (Oleic acid) and octadecanoic acid (stearic acid), the contents of which were 12.75%, 1.63%, 78.54% and 2.54%, respectively. Moreover, saturated fatty acids accounted for 15.29% of total fatty acids and unsaturated fatty acids accounted for 80.17% of total fatty acids. After the tea oil extracted by the petroleum ether was further refined, the parameters of its physiochemical indexes had more advantages over those of cold-pressed tea oil. Meanwhile, these parameters were meet the national standards.3. The investigation of extraction process of tea saponin from the camellia cake. Using ethanol as solvent, the influences of reaction conditongs such as extraction times, the amount of ammonia added to the system, ethanol concentration, stock ratio, extraction temperature and extraction time on the yield of tea saponin were systematically inspected. Then by orthogonal test, the optimum extraction technology of tea saponin were received: extraction temperature 78℃, solid to liquid ratio of 1:10 (g/ml), extraction time of 55min, ethanol concentration 70% and the amount of ammonia 0.1%, Under these factors, the yield and content of tea saponin were up to 22.41% and 68.16%.4. The study of the purification of tea saponin. We investigated the adsorption and desorption performance of the selected macroporous resin HPI450A which was fit for the production of tea saponin. The results indicated that the adsorption properities of Macroporous resin was affected by many factors, such as adsorption time, sample concentration, temperature, the sample solution pH. The optimum experimental parameters obtained were: adsorption time 4 hours, the sample concentration was 10mg/ml; room temperature; the sample solution pH 6. In the process of elution purification, there are some procedures that were as follows: the first step, removed impurities with 30% ethanol; the second step, high purity tea saponin was obtained with 70% ethanol; the end step, eluted impurities with 96% ethanol. The elution objects by 70% ethanol was decolorizated by H₂O₂. There was a good bleaching effect by the experimental parameters which were that the solution's pH value was 10, the H₂O₂ addition was 5%, water bath temperature was 80℃and response time was 90min. and then recrystallized twice with 80% ethanol. Finally, the product was light yellow and its purity was up to 96.21%.5. Used tea oil and tea saponin of extraction and purification process, we can get tea oil and three kinds of tea saponin products which the contents were greater than 30%,60%,90% for the comprehensive utilization with the camellia cakes, respectively.