Study On Extraction And Function Of Polyphenols And Theabrowns In Pu'er Tea

Pu'er tea is a microbially fermented Chinese tea made from the leaves of large-leaf species tea plant in Yunnan province. Microbial fermentation is indisensable in the processes for Pu'er teas, known as post-ferentation. So Pu'er tea has a great market potential.The method of extraction and purification process of polyphenols and theabrowns in Yunnan Pu'er tea & the function of lipid components of Pu'er tea extraction was studied in this paper This research provides a new way for Pu'er tea comprehensive processing and industrial developing and promotes research and development of functional food in Pu'er tea in the future.1 Study on comprehensive extraction technology of polyphenols and theabrowns in Pu'er teaTo Pu'er tea as raw material, the influence of extraction temperature, extraction time and the ratio of tea to solvent on extraction rate of polyphenol and theabrowns was studied. The results showed that all parameters affected the extraction rate significantly, and the effects of extraction temperature was extremely remarkable. The order of the factor was:the extraction temperature >extraction time> the ratio of tea to solvent. The trend of polyphenols and theabrowns was almost consistent. The optimal process parameters were:using water as extract solvent, the ratio of tea to solvent was 1:25, and extracting at 100℃for 60min.Then the tea polyphenols can up to 9.04% and the theabrowns extraction rate can reach 93.15%.2 Study on isolation and purification of polyphenols and theabrowns in Pu'er teaAbsorption and desorption specialities of D101, S-8, AB-8, HP-20, NKA-9, LSA-7, XAD-7HP, D201, polyamide nine kinds of macroporous resin to TBs were studied. The D101 resins were selected as absorbents to purifiy TBs & its absorption rate is 85.27% and desorption rate is 88.23%.The process to purify TBs by D101 macropore resin method was optimized. The concentration of pu'er tea pigments color differenceΔE* was diluted about 60 & PH value was adjusted to 4 with 10% hydrochloric acid and the flow rate was 3 BV/h with 30% alcohol elution.3 Study on Pu'er tea polyphenols and theabrowns for reducing blood lipidsFour pu'er tea fractions including ethyl acetate fractions(polyphenols) n-butanolfractions (including theaflavins and thearubigins), the finally extract water fractions(crude theabrowns) and theabrowns after D101 macropore resin absorption and desorption(pure theabrowns)was selected to do hyperlipidemic experiment with male mice. The body weight, fat weight, liver weight and serum levels of TC, TG, HDL-C and liver cell slice were used as factors to evaluate lowering blood lipids of pu'er tea fractions.The results showed that Pu'er tea polyphenols and theabrowns could effectively manage serum lipids in hyperlipidemic mice. The pu'er tea polyphenols and purified theabrowns reduced noticeably the content of serum TC and reduced significantly the content of serum TG. n-butanol layer fractions of pu'er tea extracts and crude theabrowns could significantly reduce serum TG levels in hyperlipidemic mice. Mice liver cells in biopsy showed various pu'er tea extracts can effectively prevent fat cells in mice from damaging their normal structural, especially the polyphenols and purified theabrowns.