The Functional Components In Tea Flower And Their Bile Salts Binding Study In Vitro

The functional components including tea polyphenol, caffeine and polysaccharide intea flowers were extrcted and compared in bile salt binding capacity in vitro in this paper. Teaflower polysaccharide was purified by removal of proteins by the Sevag method and TCAfollowed by decoloring by macroporous resins and separation by DEAE-Sepharose Fast Flowchromatography. Water-soluble protein was extracted from tea flower by salting out withammonium sulfate and purified by DEAE-Sepharose Fast Flow chromatography. Optimalconditions for the salting out and DEAE-Sepharose Fast Flow chromatographic separation ofwater-soluble proteins were determined. Four different extraction processes were used toobtain total dietary fiber (TDF) from tea flower residue. The physicochemical properties(including water-holding capacity, oil-holding capacity, swelling capacity, and bile saltadsorption capacity) of the prepared TDF products were also determined.Killed black-dried of fresh tea flowers was found to have the best bile salt-bindingcapability. A significant correlation was found between bile salt-binding capacity and thecontents of tea polyphenol, polysaccharide, caffeine. Tea polyphenol exhibited the strongestbile salt-binding capability,2.06mol/mL for SC,2.34mol/mL for SGC and1.31mol/mLfor STC. Sevag method was found as the optimum protein removal method, and theconditions follows: at5:1of polysaccharides solution to Sevag reagent, four times extraction.The polysaccharides solution was decolored by macroporous resin D101, and thepolysaccharides solution was separated by DEAE-Sepharose Fast Flow chromatography, foureluting compounds were obtained.Saturation of ammonium sulfate (80%) was used precipitate tea flower water-solubleproteins in the filtrate and the best elution results for water-soluble proteins onDEAE-Sepharose Fast Flow column were achieved at pH5.0and10mmol/L phosphatebuffer as the eluent at room temperature. PrШexhibited the best bile salt adsorption abilityfollowed by peak PrⅡand Pr.Sulfuric acid treatment, sodium hydroxide treatment, sequential treatment with sulfuricacid followed by sodium hydroxide and sequential treatment with trypsin followed by sulfuricacid were used to prepare total dietary fiber (TDF) from tea flower residue. Among the four extraction processes, sulfuric acid treatment had the highest extraction recovery (76.4%),swelling capacity (4.90mL/g). Sulfuric acid treatment had the highest bile salt adsorptioncapacities,0.80mol/mL for SC,1.03mol/mL for SGC and2.01mol/mL for STC.Sequential treatment with trypsin followed by sulfuric acid had the highest water-holdingcapacity(3.62g/g) and adsorption capacity for lard and peanut oil(2.86g/g and3.04g/g,respectively).