Study On Antioxidtive Activities In Vitro Of Tea

Study on the effect of antioxidant in vitro in tea. The main result is as follow:1. Carried out the concentration of tea infusion clearance of DPPH free radical screening research. The results showed that the clearance rate of DPPH free radical reduced with decline in the concentration of six tea infusion, tea infusion diluted 200 times, the average clearance rate of DPPH free radical is closer to IC₅₀. Therefore, choosing the tea infusion diluted 200 times as a reagent to carry out the test of clearance rate of DPPH free radical, to provide a more scientific method for the test.2. Has carried on the different processing technique clearance of DPPH free radical research. The results showed that the DPPH free radical-scavenging was obvious difference brought by different processing technique. The DPPH free radical-scavenging order is oolong, white tea, dark green tea and black tea. From the angles of anti-aging and antioxidation, drinking oolong and white tea were more healthy.3. In the view of suited-processing of different tea varieties, has carried on the DPPH free radical-scavenging on the main varieties of Fujian province. The results showed that the tieguanying is better than the others in the DPPH free radical-scavenging, varieties such as tieguanyin is process and making oolong tea were higher than the others in the DPPH free radical-scavenging and main biochemical composition. From the tea antioxidation, suited-processing of different tea varieties has a certain scientific basis.4. Carried out the effect of export tea antioxidation of Fujian province research. The results showed that the clearance of DPPH free radical of superfine tieguanyin, superfine sezhong, superfine shuixian, superfine jasmine tea were: 28.50%, 22.41%, 25.63%, 34.20%, were lower than baihao-yinzhen(66.75%). The results also showed that from the DPPH free radical-scavenging, white tea is more than the others.5. Carried out the effect of brewing tea by different times and Temperatures has carried on the DPPH free radical-scavenging and main biochemical composition. The results showed that the main biochemical composition in low-temperature brewing 900min is quite close even exceed in high-temperature brewing 60min. For the main biochemical composition, temperature has obviously effect in the short brewing time. The time change law of biochemical composition by low-temperature brewing has a similar law of high-temperature brewing. But the leaching rate was slower, fitting to prolong the brewing time, the leaching content of tea biochemical composition was satisfied the drinking requirements completely, to provide optimum basis for the feasibility of low-temperature.