HPE is not adapted to extract these 3 compounds. Li et al. (2012) studied the HPE of Cit-rus reticulata flavones (methanol; ratio: 10 ml/g; 20 min, 160◦C,10 MPa). The authors reported that an increase of extraction time from 5 to 20 min leads to an increase of the extrac-tion efficiency of flavones.