title: Ultrasonic extraction of phenols from olive mill wastewater: comparison with conventional methods.
abstract: Recovery of phenols from olive mill wastewater (OMWW) was studied, comparing five sample preparation methods: filtration, solid-phase (SPE), liquid-liquid (LLE) and ultrasonic (US)-assisted extraction of liquid and solid (freeze-dried) OMWW. Results showed that ultrasonication is a good alternative to conventional solvent extractions, providing higher recoveries at both levels of individual and total phenol yields. Sonication of liquid OMWW in organic solvent was more efficient vs its nonassisted counterpart (agitation), but did not provide a representative phenol chromatogram due to ethyl acetate use. By contrast, the US-assisted extraction of freeze-dried OMWW (3 × 20 min) in 100% methanol (1.5 g/25 mL, w/v) offered the highest qualitative-quantitative phenol yields without any US-induced alterations. Moreover, freeze-drying is an excellent preservation of initial liquid OMWW, holding a great potential for delayed analysis. This study is also the first report that Slovenian OMWW may be utilized as a valuable source of phenols, especially hydroxytyrosol and tyrosol.
authors: Wine Research Centre, University of Nova Gorica, Vipavska 11c, 5270-SI Ajdovščina, Slovenia.
authors: Tina
authors: T
authors: Jerman Klen
authors: Branka
authors: B
authors: Mozetič Vodopivec
mesh_terms: D000890:Anti-Infective Agents / Q000302:isolation & purification; D000975:Antioxidants / Q000302:isolation & purification; D005525:Food-Processing Industry; D007220:Industrial Waste / Q000032:analysis*; D000069463:Olive Oil; D010636:Phenols / Q000302:isolation & purification*; D010626:Phenylethyl Alcohol / Q000031:analogs & derivatives / Q000302:isolation & purification; D010938:Plant Oils; D017524:Slovenia; D014465:Ultrasonics
chemical_list: D000890:Anti-Infective Agents; D000975:Antioxidants; D007220:Industrial Waste; D000069463:Olive Oil; D010636:Phenols; D010938:Plant Oils; C005975:3,4-dihydroxyphenylethanol; C011867:4-hydroxyphenylethanol; D010626:Phenylethyl Alcohol