title: Optimisation of supercritical fluid extraction of flavonoids from Pueraria lobata.
abstract: Supercritical carbon dioxide extraction was employed to extract flavonoids from Pueraria lobata. The optimal conditions for flavonoid extraction were determined by response surface methodology. Box-Behnken design was applied to evaluate the effects of three independent variables (pressure, temperature and co-solvent amount) on the flavonoid yield of P. lobata. Correlation analysis of the mathematical-regression model indicated that a quadratic polynomial model could be employed to optimise the supercritical carbon dioxide extraction of flavonoids. From response surface plots, pressure, temperature and co-solvent amount exhibited independent and interactive effects on the extraction of flavonoids. The optimal conditions to obtain the highest flavonoid yield of P. lobata were a pressure of 20.04MPa, a temperature of 50.24°C and a co-solvent amount of 181.24ml. Under these optimal conditions, the experimental values agreed with the predicted values, using analysis of variance, indicating a high goodness of fit of the model used and the success of response surface methodology for optimising supercritical carbon dioxide extraction of flavonoids from P. lobata.
authors.affiliation: School of Marine Science and Technology, Huaihai Institute of Technology, Lianyungang 222005, China.
authors.forename: Lingzhao
authors.initials: L
authors.lastname: Wang
authors.affiliation: South China Botanical Garden, Chinese Academy of Sciences, Guangzhou Leyiju 510650, China. Electronic address: yangbao@china.com.cn.
authors.forename: Bao
authors.initials: B
authors.lastname: Yang
authors.affiliation: School of Marine Science and Technology, Huaihai Institute of Technology, Lianyungang 222005, China.
authors.forename: Xiuqiao
authors.initials: X
authors.lastname: Du
authors.affiliation: South China Botanical Garden, Chinese Academy of Sciences, Guangzhou Leyiju 510650, China.
authors.forename: Chun
authors.initials: C
authors.lastname: Yi
keywords: Flavonoid; Pueraria lobata; Response surface methodology; Supercritical fluid