The use of artichoke peroxidase to remove phenols from olive mill waste water.

Abstract: The use of peroxidase (POD) from artichoke (Cynara cardunculus L. subsp. scolymus (L.) Hayek) leaves to remove phenols present in olive mill waste water (OMWW) was studied. The enzyme extraction was performed using an aqueous two phase polymer system. The phenol concentration was assayed using the Folin-Ciocalteu method. The optimal reaction conditions were evaluated. The highest phenol removal was obtained using 4 mM H(2)O(2) and an incubation of 24 hours. The enzyme showed a good activity in a broad range of pH (from 4 to 7) and temperature (from 5 to 50 degrees C). In optimal enzymatic conditions, a reduction of more than 60% of initial phenol concentration was observed. High pressure liquid chromatography (HPLC) analysis of OMWW untreated and treated with POD extracts revealed that enzyme treatment brought about changes in the original OMWW polyphenolic profile. In particular the removal of verbascoside, hydroxytyrosol, and two caffeic acid derivatives was noticed. The results showed that the soluble POD from artichoke leaves could have a promising perspective in OMWW phenol removal, due to its broad pH and temperature working range and its cheap source.