Optimisation of phenolics recovery from Vitex agnus-castus Linn. leaves by high-pressure and temperature extraction

To optimise recovery of phenolics from Vitex agnus-castus Linn., a non-conventional high-pressure (2-24 bar) and temperature (100-180 degrees C) extraction method was used under nitrogen atmosphere with methanol as a solvent. Optimal temperature was between 100 and 140 degrees C, and optimal extraction time was about one half that of conventional solid/liquid extraction at room temperature. Final yields of total polyphenols, total flavonoids, o-diphenols and anthocyanins extraction were 2.0, 3.0, 2.5 and 11-fold those obtained by conventional extraction.