Four Types Of Tea Composition Analysis

In this paper, a series of oolong tea,black tea and dark tea and its chemical constituents and antioxidant activity are studied.Aroma components are analyzed by gas chromatography-mass spectrometry (GC-MS).The Oligomeric Proantho Cyanidins is determined by UV spectrophotometry.The contents of tea polyphenols and caffeine are determined by HPLC.Flow injection chemiluminescence determination of antioxidant activity of tea samplesResearch two seasons and the three production process of Tieguanyin on aroma components. Five kinds of teas aroma components are compared.And 10 different origins of black tea and 13 types of Phoenix Mountain in Guangdong oolong tea aroma components were determined. Because the determination of proanthocyanidins of teas has not been reported, Using low concentration of vanillin-hydrochloric acid method for the determination of teas. Orthogonal experiments are used to choose the extraction conditions, the method in 0.20-1.50mg/mL range, recovery rate between the 96.7% to 101%, coefficient of variation less than 0.06%. Using HPLC analysis the tea polyphenols and caffeine at the same time. C18 column is used and the column temperature is 30℃, the flow rate was 1.0mL/min, mobile phase ratio of 30:70 methanol and water conditions. Experiments use carbonate buffer solution -luminol-pyrogallol solution, flow injection chemiluminescence determination are measured antioxidant activity of tea.The aroma components of tieguanyin in spring is more than autumn.High composition material of three production process of teiguanyin are acacia limonene and nerolidol. Indicating.It is found that five teas have different components of aroma, the maximum difference is yellow tea. Component of green tea and white tea have the greater degree of coincidence. Black tea from different areas are a total of linalool and hexanal.13 dancong oolong tea have a common fragrance component, but the highest levels of compounds are different. Maximum absorption of proanthocyanidins in 500.nm, green tea>oolong tea>black tea,.Ripe Pu'er tea has not have proanthocyanidins. The content of polyphenols, green tea> oolong tea> black tea, Pu'er> ripe Pu'er.The caffeine content of Yunnan teas is 4.5107-6.1446mg/g. The antioxidant activity of yunnan teas, green tea>oolong tea>black tea,Pu'er tea > ripe Pu'er. This shows that proanthocyanidins,tea polyphenols and antioxidant capabilities in direct proportion with the concentration, increased antioxidant activity.