Research Of Dark Green Tea's Chemical Composition And Anticccoxidation

The chemical composition and anticccoxidation of a series of dark green tea were studied in this paper. Volatile oil constituents of dark green tea were analyzed by Gas Chromatograph-Mass Spectrometry(GC-MS). The contents of tea polyphenol, flavonoid, tea green pigments,and the free amino acid; were determined by Ultraviolet Spectrophotometry. The content of caffeine was determined by High Performance Liquid Chromatography (HPLC). Anticccoxidation of a series of dark green tea were determined by flowing injection chemiluminescence.Volatile oil of 4 kinds of dark green tea were determined and analyzed by GC-MS,with wet distillation extraction(WDE) and simultaneously distillation extraction(SDE) of two different extraction methods.The content of relative percentage of each ingredient was determined by the gas chromatography area normalizing. The hexadecyclic acid and the linalool were included in volatile oil and the contents were higher.Tea polyphenol' contents of 10 kinds dark green tea were determined by the ferrous tartrate color method,the biggest absorption wave length were 540nm,the content was 24.79%~37.51%; Take the Mongolian oak Pi Su as the standard, the flavonoid' content of 23 kinds dark green tea were determined by the aluminum trichloride color method, the biggest absorption wave length is 420nm, the method coefficient of variation was smaller than 0.068%, the recovery of the method was 97.5%~103.5%, the content was 0.083~2.4698mg/g;The tea green pigments' relative contents of 23 kind of dark green tea were determined, the biggest absorption wave length is 660nm, the optimum content of the cupric acetate had determined , was 4.0mL, the method coefficient of variation was smaller than 0.28%, the recovery of the method was: 101.32%~104.9%, the content was 6.445～128.58mg/g; Take the glutanic acid as the standard,the free amino acid' content of 23 kinds of dark green tea were determined by yin the triketone color method, the biggest absorption wave length was 570nm, the method coefficient of variation was smaller than 0.85%; the recovery of the method was 93.5%~103%, the content was 1.5%~4.97%;The caffeine' content of 23 kinds of dark green tea were determined by HPLC, the mobile phase was: water-methyl alcohol-ethanoic acid-dimethyl amide =70∶3 0∶0 .05∶0.25, the method coefficient of variation was smaller than 3.96%, the recovery of the method was 91.7%~103.8%; Anticccoxidation of 24 kinds of dark green tea were determined by flowing injection chemiluminescence, IC50 value was 0.16~5.99mg/mL.