Research On The Chromatography Analysis & Related Properties Of Tea Flavonoids

Flavonol, Anthocyanins from the tea is a kind of important water-solublepigment, Making a significant impact on tea color, tea leaf quality, but also becauseof its a variety of pharmacological effection and health functions.Through researchs on the chromatography action of three kind of teaflavonoids, The effects of mobile constituents, gradient elution conditions, detectionwavelength,column temperature on the isolation of flavonoids, the RP-HPLCanalysis method was established. The method is simple, rapid, accurate and can beapplied to the sample survey.. Kromasil C18 5μm (4.6×200mm mmi.d) column isused, methanol -0.4% phosphoric acid as a mobile phase gradient elution and UVdetection at 370 nm was examined. The results showed myricetin, quercetin andkaempferol in selected concentrations, linear relationship,the average recovery rateis 102.6%,99.5%,101.3% respectively.; 3.8%,3.6%,2.2% respectively.The high performance thin-layer chromatographic method of flavonols. In teawas developed by use of chloroform:methanol:formy-lacid(44.8:5:0.2) on.silica gelGF254 plate. The Rf value of three kinds of flavonols was between 0.3-0.7. Thecalibration curves are lineral. The results showed this method for determination offlavonols in the hydrolysis sample of tea dry leaves was simple, rapid, sensitive andreproducible.The extracting conditions of flavonols compounds from tea by thealcoholextracting and ultrasonic extracting methods are studied. The result s show that theultrasonic extracting is the better way, which is testnficol by using the factorial andorthogonal design. Theoptimum conditions are 1:15, of 70% ethanol to douse thedried tea.and ultrasonic treatment lasted for 15 min., then dipped in water 70℃fortwo hours, The extraction of flavonols is as high as 5.87mg/g.In this paper, the thermal, optical, oxidizer, reducer, Vc, metal ions, acidity onthe stability of proanthocyanidins. The results showed : Different pH, anthocyaninabsorption characteristics will be different. Light and heat will cause degradation ofanthocyanins, and the higher the temperature, the longer the heating time, the moreeasily degradable anthocyanins; Sunlight exposure can increase degradation as compared with indoor natural light; Fe²⁺ and Cu²⁺ ions have a greater effect on thecolour of anthocyanins than K⁺, Mg²⁺, Ca²⁺ ions do; H₂O₂, Na₂SO₃ can make achanging at anthocyanins spectral characteristics, so absorbance value decreases at520nm, which shows the antioxidant & the resistance capacity of anthocyanins areboth not so good. Absorbance characteristics of anthocyanins will not be changedimmediately as adding the vitamin C, However, the longer the time is, the more theconcentration of vitamin C anthocyanin degrades.Based common O₂^-·,DPPH and·O H vitro antioxidant models, Rutin is usedas contradistinguish on the removal of superoxide anion O₂^-·capacity,free radicalscavenging capacity, removing Hydroxyl Radical·OH capacity. Test results showthat the concentration of the given context, the three proanthocyanidins systemscavenging effects are greater than rutin.