Back to Search Start Over

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.

Authors :
Mateos R
Domínguez MM
Espartero JL
Cert A
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