Preparation And Microencapsulation Of Flavone Aglycone

The flavone aglycone was studied in this thesis, which is the main functional composition in flavone compounds. Based on the optimization of extraction techniques of flavone compounds, the flavone aglycone was prepared from flavone glycosides byβ-Glycosidase hydrolysis. The eliminating effect and antioxidant capabilities of flavone glycosides and flavone aglycone were also evaluated. In addition, the flavone aglycone was protected by microencapsulation.Inpregnant technique was use to extract the ginkgo flavone. The optimal condition for extraction was as follows: particles being 40-60 meshes, 70%of alcohol, solid to solvent ratio of 1:5 (g/mL), extracting 3 times at 70℃and lasting l h for each time. As a result, the flavone extraction rate was as high as 92.31%.The macro-porous resin of AB-8 was most suitable for purifying flavone glycosides among the six kinds of macro-porous resins being studied, with the adsorption of 42.14 mg/g. The best adsorption condition was the sample concentration of 0.90mg/mL, flow velocity of 0.5BV/h. The highest desorption of 96% was obtained with the following condition: 70%of alcohol used as eluent, the volμme of eluent of 4BV. After the purification, the flavone content was as high as 25.01%.The enzymatic hydrolyzing conditions for flavonoids were studied for GBE (Ginkgo biloba extract). Based on the single factor and orthogonal experiments ,the optimal hydrolyzing conditions was as follows: concentration of substrate of 5 mg/mL, enzyme to substrate ratio of 1/2000 (mL/g), hydrolyzing for 6h at 50℃with the original pH value of solution. The increase of reduced sugar was 92.31% at optimal hydrolyzing conditions. The eliminating effect of ginkgo flavone to the DPPH free radical was same as that of flavone aglycone, while the antioxidation effect of aglycone of ginkgo flavone was better than that of ginkgo flavone.The microencapsulation of flavone aglycone was prepared by spray drying, with the mixture of whey protein and maltodextrin compound as wall material at the rate of 2:7 (whey protein : maltodextrin, w/w) and the content of core material being 10 %.The optimal techniques parameter of microencapsulation was as follows: homogelyzing at 40 MPa for 2 times and 20 minutes each time, the temperature for inlet and outlet wind being 200℃and 90℃, respectively. The microencapsulation rate of flavone aglycone was 91% at optimal conditions. The SEM picture of microencapsulation of flavone aglycone showed that embed effect was desirable.