Study on technologies for total flavone extraction from lotus leaf by supercritical CO_2 fluid

Supercritical CO2 fluid was used to extract total flavones from lotus leaf,the extraction rate was used as the evaluation index and extraction pressure,extraction temperature,the concentration of entrainer and extraction time as affecting factors.The optimal extraction process was determined by orthogonal experiments.The optimum extraction conditions were as followed: extraction pressure 45 MPa;extraction temperature 36 ℃;the concentration of entrainer 100%;extraction time 120 min,Under the conditions,the extraction rate of total flavones reached 3.311 5 mg/g.