Study On Thea Brownine In Different Processing Pu'er Tea And Its Chang Along With Preservation

Yunnan pu'er tea is a special tea welcomed by consumers. It has an unique process of producing, pile fermentation fermentation and preservation aging the abundent polyphenols sugar and protein in the sunshine withered, coarse tea converted to the unique flavor of pu'er tea involving multi anaerobic aerobic microbes and a series of hydrothermal feedbacks. TB from oxidized polyphenols is the main, aqueous fusion composition in pu'er tea soup, forming the unique flavor of pu'er tea. TB content in fermented pu'er tea occpuies 7-15% of dry pu'er tea. TB content is the important index to scaling pu'er tea quality.Study shows TB forming mechanism: The oxidized catehins feedback with amylose protein nucleic acid to form undialyse macromolecule polymer. Because of its complicated composition, the thorough study and report of TB is almost blank. Thus, this study of the influence of polyphenol pigments to pu'er tea color and lustre and the influence of preservation time to pigments in two different methods in the processing of pu'er tea starts with TB's extraction separation color and lustre determination characteristic substance identification. First, using different age Yunnan pu'eir tea through traditional processing(unfermented) and modern pile fermentation processing (fermented)as raw material; then analyzing the pertinence of pigments content and moisture contents PH, external color and lustre soup color; and also discussing the method of checking and measuring and analyzing TB; while simultaneously putting up a series of preliminary research on TB in pu'er tea soup combining surpass membrane filtering detecting composition change and extracting preparation. The result is as follows:(1)The result of analyzing the pertinence among TF TR TB, moisture content in fermented and unfermented pu'er tea at different preservation time shows: there are invariable rules between the pigments changing and preservation time in fermented and unfermented pu'er tea; Corresponding with preservation, the TF TR TB and total tea pigments have a trend to increase in unfermented pu'er tea; likewise, the higher the moisture content, the faster the rate of change correspondingly. For fermented pu'er tea, corresponding with preservation, TF TR and total tea pigments content decreased but TB increased. When the preservation time is prolonged in years, the pH in unfermented pu'er tea has little increase trend.(2)From chromatic aberration(Hunter Lab) analysis: unfermented pu'er tea is brighter than that of the fermented, but TB content in fermented tea is a lot higher than that in the unfermented; and TB content has negative correlation with brightness; namely, the higher the TB content, the darker the color and lustre. Corresponding with preservation, the color and lustre of fermented pu'er tea has a decreasing trend.The color of fermented pu'er tea soup leans toward red, but the unfermented leans toward green. Corresponding with preservation, degree of yellowness and redness increased in fermented and unfermented pu'er tea soup.and the redness of dry pu'er tea also increased,but there is no obviouspertinence between yellowness and preservation.And there is no obvious pertinence between TF> TR content and Hunter L a b.The phenomenon accords with intensified oxidation in pu'er tea.?In the systermatic analysis test, the result is found that TB content in un-ground tea sample is higher than that of the ground, it shows that un-ground tea sample is suit for TB extraction and the extraction rate is higher; Using normal butyl alcohol to extract at 8*C, detected TB in tea soup is the highest.?TB molecular weight is different in pu'er tea; there is important influence of aperture withholding rate to TB content detained in pu'er tea,if the tea soup is filtered by 10 ten thousand aperture, 22.46% physical and chemical materials is detained, if filtered by 5 ten thousand aperture only 8.27% TB composition is detained and most are phenol matters.?TB extraction and purging test show: the effect of using trichloromethane and Ethyl acetate to purge polyphenol> total nitrogen in TB is not obvious; It illuminates that polyphenol and total nitrogen is the main combinative compositions in TB.?There are 2.342mg/ml TB and TP^ AA, T-N, T^ Caf> GA and etcs in the tested pu'er tea sample. Polyphenol and GA is the most common among these small molecular materials that composed TB; respectively occupying 30.23%> 12.89%. The quantity up to 31.19%> 9.83% after refining, it shows that TB is a polymer of phenol matters.?Using HPLC to analyze GA a composition of TB: Waters6000 high pass filter analysis system, C18 column(4.6* 150mm), mobile phase.- A—2% acetic acid; B—100% acetonitrile; detected wavelengh: 380nm; purging condition: mobile phase B changed linearly from 8% to 12.6% in ten minuteso...