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Antioxidant effect of phenolic compounds, alpha-tocopherol, and other minor components in virgin olive oil.
Antioxidant effect of phenolic compounds, alpha-tocopherol, and other minor components in virgin olive oil.
- Source :
-
Journal of agricultural and food chemistry [J Agric Food Chem] 2003 Nov 19; Vol. 51 (24), pp. 7170-5. - Publication Year :
- 2003
-
Abstract
- The effect of acidity, squalene, hydroxytyrosol, aldehydic form of oleuropein aglycon, hydroxytyrosyl acetate, tyrosol, homovanillic acid, luteolin, apigenin, alpha-tocopherol, and the mixtures hydroxytyrosol/hydroxytyrosyl acetate, hydroxytyrosol/tyrosol, and hydroxytyrosol/alpha-tocopherol on the oxidative stability of an olive oil matrix was evaluated. A purified olive oil was spiked with several concentrations of these compounds and, then, subjected to an accelerated oxidation in a Rancimat apparatus at 100 degrees C. Acidity, squalene, homovanillic acid, and apigenin showed negligible effect. At the same millimolar concentrations, the different o-diphenolic compounds yielded similar and significant increases of the induction time, alpha-tocopherol a lesser increase, and tyrosol a scarce one. At low concentrations of o-diphenols and alpha-tocopherol, a linear relationship between induction time and concentration was found, but at high concentrations the induction time tended toward constant values. To explain this behavior, a kinetic model was applied. The effect of the mixtures hydroxytyrosol/hydroxytyrosyl acetate was similar to that of a single o-diphenol at millimolar concentration equal to the sum of millimolar concentrations of both compounds. Concentrations of tyrosol >0.3 mmol/kg increase the induction time by 3 h. The mixtures hydroxytyrosol/alpha-tocopherol showed opposite effects depending on the relative concentrations of both antioxidants; so, at hydroxytyrosol concentrations <0.2 mmol/kg, the addition of alpha-tocopherol increased the induction time, whereas at higher hydroxytyrosol concentrations, the alpha-tocopherol diminished the stability.
Details
- Language :
- English
- ISSN :
- 0021-8561
- Volume :
- 51
- Issue :
- 24
- Database :
- MEDLINE
- Journal :
- Journal of agricultural and food chemistry
- Publication Type :
- Academic Journal
- Accession number :
- 14611189
- Full Text :
- https://doi.org/10.1021/jf034415q