Phenolic Compounds in Olive Oils Intended for Refining:  Formation of 4-Ethylphenol during Olive Paste Storage

• Published in: Journal of agricultural and food chemistry 2004-12, Vol.52 (26), p.8177-8181
• Main Authors: Brenes, Manuel, Romero, Concepción, García, Aranzazu, Hidalgo, Francisco J, Ruiz-Méndez, M. V
• Format: Article
• Language: English
• Subjects: 4-ethylphenol; Biological and medical sciences; Chromatography, High Pressure Liquid; crude olive pomace oil; Fat industries; Food Handling; Food industries; food processing; food storage; Fundamental and applied biological sciences. Psychology; lampante olive oil; Odorants - analysis; oil refining; Olive Oil; olive paste; olive pulp; phenolic compounds; Phenols - analysis; Phenols - chemistry; Plant Oils - chemistry; second centrifugation olive oil
• ISSN: 0021-8561; 1520-5118
• DOI: 10.1021/jf0402532

The phenolic composition of “lampante olive oil”, “crude olive pomace oil”, and “second centrifugation olive oil” was characterized by high-performance liquid chromatography with UV, fluorescence, and mass spectrometry detection. The phenolic profile of these olive oils intended for refining was rather similar to that previously reported for virgin olive oil. However, a new compound was found in these oils, which is mainly responsible of their foul odor. It was identified as 4-ethylphenol by comparison of its UV and mass spectra with those of a commercial standard. Although 4-ethylphenol was discovered in all oils intended for refining, its presence was particularly significant in “second centrifugation olive oils”, its concentration increasing with time of olive paste storage. Similar trends were observed for hydroxytyrosol, hydroxytyrosol acetate, tyrosol, and catechol, the concentration of these substances reaching values of up to 600 mg/kg of oil, which makes their recovery for food, cosmetic, or pharmaceutical purposes attractive. Keywords: Olive oil; phenolic compounds; 4-ethylphenol; refining