Solvent- SCF co- extraction of tea polyphenols from black tea

Homemade black tea as research object,Supercritical CO2 fluid extraction( SCF),Solvent leaching and SCF- Solvent co- extraction were used to extract tea polyphenols from black tea with orthogonal tests to optimize the extraction technology,then the yields and purities of tea polyphenols in the samples which were calculated after ultraviolet detection at 765 nm with gallic acid as standard sample. And the DPPH· clearance rates were studied between the extraction methods.The results showed that the Solvent- SCF co- extraction was the best method.After Solvent leaching( ethanol concentration 80%,solid to liquid 1 ∶ 10 g / m L,extraction temperature 60℃,extraction time 2h),the solution were extracted with SCF at 25 MPa,50℃ for 2h.Under the best conditions for the Solvent- SCF co- extraction method,high yield and high purity of tea polyphenols can be obtained with yield of6.36% ± 0.81% and purity of 41.22% ± 3.19%.The DPPH·clearance rate of products was 90.64% ± 0.0187%.This method was environmental protection,not adding any harmful solvents,which can provide the reference for the further development of black tea research.