title: Antioxidant activity of phenolic fractions in olive mill wastewater.
abstract: Olive mill wastewater (OMW) contains a substantial amount of valuable antioxidant phenols that can be recovered for industrial application as food additives and pharmaceuticals. The present study was aimed at extracting different phenolic OMW fractions, and determining their antioxidant potential. Five different OMW fractions were obtained using fractionation techniques, their antioxidant potential determined by DPPH, ORAC and a β-carotene bleaching test. The total phenol level ranged between 115 and 170 mg/l. The phenolic compounds present in individual fractions were identified using the HPLC-PAD method, where the main compounds were hydroxytyrosol, tyrosol, caffeic acid, vanillic acid, verbascoside, oleuropein, ferulic acid, and p-coumaric acid. The five OMW fractions showed different antioxidant levels depending on the test used. DPPH test showed that the fraction of alkyl aromatic alcohols (AAAs) was the best with EC(50) of 20 mg/l and the pure hydroxytyrosol with 2 mg/l. ORAC test showed that AAA and semi hydrolysed total phenol (s-TP) fractions were significantly better than Trolox when compared to 20 mg/l of Trolox.
authors: Institute of Applied Research (Affiliated with University of Haifa), The Galilee Society, P.O. Box 437, Shefa-Amr 20200, Israel. hazaizeh@yahoo.com
authors: Hassan
authors: H
authors: Azaizeh
authors: Fares
authors: F
authors: Halahlih
authors: Naim
authors: N
authors: Najami
authors: Doris
authors: D
authors: Brunner
authors: Martin
authors: M
authors: Faulstich
authors: Ahmed
authors: A
authors: Tafesh
mesh_terms: D000975:Antioxidants / Q000032:analysis*; D002851:Chromatography, High Pressure Liquid; D007220:Industrial Waste / Q000032:analysis*; D031658:Olea / Q000737:chemistry*; D010636:Phenols / Q000032:analysis*; D062065:Wastewater / Q000032:analysis*
chemical_list: D000975:Antioxidants; D007220:Industrial Waste; D010636:Phenols; D062065:Wastewater