Optimization of Microwave-High Pressure Assisted Extraction of Flavonids from Ginkgo biloba Leaves

To improve the flavonoids yield from Ginkgo biloba leaves,the combination of microwave and high pressure technique was employed to extract the flavonoids,which were isolated and purified by macroporous resins.On the basis of single factor experiment,Box-Behnken combination menthod was used to study the effect of the three factors(pH,microwave extraction time and pressure) on the flavonoids yield and the optimum conditions listed as follows: microwave extraction time 2.58 min,276.62 MPa pressure,9.68 pH and solid-liquid 30 mL∶1 g.Under the optimal condition,the yield rate of flavonoids compound was 5.14%.By comparing the two factors of adsorptive capacity and desorption of the two adsorption resins,results showed that: AB-8 was the optimal resin of the two kinds of macroporous resins to separate the flavones from Ginkgo biloba flavonoids.The static adsorptive capacity,adsorptive capability rate and desorption rate were 16.2 mg/g,81.1% and 80.5%,respectively.After purification,the purified flavonoids mass fraction was 29.3%.