title: Phenolic content of olive oil is reduced in extraction and refining.
abstract: Three grades of olive oil and ten vegetable cooking oils were analysed for their phenolic content. It was hypothesised that as olive oil passed through the chemical extraction process, polyphenols would also be removed, thus reducing the antioxidant properties of olive oil. Other commonly used edible vegetable oils were analysed for comparative reasons. Extra virgin olive oil was found to have the greatest amount (48 μg/gram of oil) of polyphenols, when compared with other olive or vegetable oils. No polyphenols were detected in sunflower, walnut, peanut or almond oils. All other oils tested had a polyphenolic content between 2 and 10 μg/gram of oil. The results of the study confirms the above hypothesis that the phenolic content of olive oil is reduced by chemical extraction and refining.
authors.affiliation: The Wesley and Greenscopes Hospitals, Brisbane, Queensland, Australia.
authors.forename: D M
authors.initials: DM
authors.lastname: Colquhoun
authors.forename: B J
authors.initials: BJ
authors.lastname: Hicks
authors.forename: A W
authors.initials: AW
authors.lastname: Reed