Extraction Of Flavonoids From Eclipta Alba And White Mulberry Root-bark By Combining Surfactant With Enzyme And Microwave-assisted Techniques

In this paper, extraction of flavonoids from Eclipta alba and white mulberry root-bark by combining surfactant with enzyme and microwave-assisted techniques was investigated.The analytic technique UV for flavonoids was founded. The effects on extraction yield of flavonoids, such as enzyme kinds and concentration, surfactant kinds and concentration, enzymatic temperature, pH of solvent, enzymatic time, liquid to solid ratio and microwave radiation time were discussed. The quadratic orthogonal rotation design was employed to investigate the optimum operating condition.The optimum operating condition of flavonoids from Eclipta alba was as follows: cellulose concentration was 1.00 g/L, enzymatic temperature was 54℃, enzymatic time was 90 min, liquid to solid ratio was 21 mL/g, pH=6.0, tween 60 concentration was 2.4 g/L and microwave radiation time was 142 s. In such condition, the extraction yield of Eclipta alba flavonoids was 1.38%. And the optimum operating condition of flavonoids from white mulberry root-bark was as follows:cellulose concentration was 0.75 g/L, tween 60 concentration was 2.0 g/L, liquid to solid ratio was 33 mL/g, pH=6.0, enzymatic temperature was 45℃, enzymatic time was 45 min and microwave radiation time was 170 s. In such condition the extraction yield of white mulberry root-bark flavonoids was 0.68%.Based on uniform design method, the prediction methods for the operating conditions and the extraction yield of flavonoids from Eclipta alba and white mulberry root-bark were established by BPNN, the relative errors were 0.17%and 0.18%. The results showed that the BPNN methods were reliable.