The Studies On The Stability And Qualitative And Quantitative Analysis Of Flavonoids In Pigment Of Winter Jujube Peel

Peel of ripened winter jujube had fresh red colour, which was the direct representation of commercial value and edible quality. The extraction of red colour pigment in winter jujube peel was treated with different factors (temperature, light, PH, several metal, reductant-oxidant ,et al), then scaned with UV-Vis spectrum in this experiment. The effects of different factors on the stability of extraction were confirmed after its component and chemical quality were elementary analysed. The extraction of flavone sample from winter jujube peel was analysed with HPLC. The condition of HPLC in analysis of flavone component, the flavone component from winter jujube and the relative ratio in flavone sample of different maturity was ascertained.The results showed:(1)Heated with different water temperature for 2h, the appearance colour faded and the absorbance reduced with the rise of temperature . The higher the temperature is, the more loss of pigment.(2)With treatment of light avoidance, straight light, dispersion light, it was discovered that the red pigment was susceptive to light, the pigment should be storaged in no light environment.(3)Among 2 cations, K+, Ca2+ both had a increasing at the absorption peak. Reductant-oxidant had little effect on stability of the pigment.(4)Different pH had effect on the colour change and stability of red pigment of winter jujube peel.(5)The best HPLC separation condition of flavone was: ODS C18 column(4.6mm I.D.×15cm,5μm);column temperature: 25℃;injecting volume;20μl; UV-280nm detector; mobile phase : V(Methanol): V(H2O)=80:20 with a flow rate of 1.0mL·min-1(with 0.5% acetic acid).(6)The extraction of flavone from winter jujube peel contained 3',4',7-trihydroxyisoflavone, 4',6',7-trihydroxyisoflavone, luteolin and chrysin. The content respectively was 0.0035%,0.0090%,0.013%,0.0028%.