Optimization of Process for Ultra High Pressure-Assisted Synchronous Extraction of Polyphenols and Flavones from Burdock Roots and Their Antioxidant Activity
The ultra high pressure (UHP)-assisted simultaneous extraction and antioxidant activity of total phenols and flavones from burdock roots were studied.To optimize the extraction process,the response surface methodology with three factors at three levels was adopted on the basis of single factor experiments.Model fitting and regression analysis of experimental data showed that two significant factors which influence total phenol and flavone yields were ethanol concentration and solid-to-solvent ratio.The optimal extraction conditions were determined as follows:75% ethanol as extraction solvent,solid-to-solvent ratio 1∶28 (g/mL),extraction pressure 236 MPa,pressure holding time 9 minutes,and room temperature.Under these optimal conditions,the yield of total phenols and flavones from burdock reached (107.83 ± 1.148) and (21.27 ± 0.950) mg/g respectively.The polyphenols extracted from burdock showed strong ferric ions chelating ability (IC50 (1.393 ± 0.011) mg/mL),2,2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging activity (IC50 (0.309 + 0.007) mg/mL) and ferric ions reducing power.
burdock rootsultra high pressuretotal phenolflavoneresponse surface methodologyantioxidant activity