Abstract:

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.

Key words: burdock roots, ultra high pressure, total phenol, flavone, response surface methodology, antioxidant activity