Valorisation of organic matter in olive mill wastewaters: Recovery of highly pure hydroxytyrosol

Abstract High grade purified hydroxytyrosol was produced in small scale by recovery from three-phase olive mill wastewaters, combining a soxhlet continuous liquid–liquid extraction procedure with two chromatographic steps, which were consistent with silica gel middle pressure and percolation on C-18 phase chromatography. The highly pure orthodiphenol was characterized by HPLC, EI-MS and 1 H-NMR methods. The convenience of this procedure and the utilization of the compound for laboratory uses are briefly discussed.