Oxidation of olive oil fortified with quercetin, caffeic acid, tyrosol and hydroxytyrosol

Abstract

Purpose

This paper aims to evaluate effects of the fortification of polyphenolic compound mixtures of quercetin, caffeic acid, tryrosol and hydroxytyrosol in olive oil oxidation.

Design/methodology/approach

The authors measured olive oxidation initiated by copper using thiobarbituric acid reactive substance, as an indicator of lipid peroxidation.

Findings

Overall, most mixture combinations exhibited oxidation similar to olive oil alone. Some mixture combinations of polyphenolic compounds acted as antioxidants; however, as the concentrations were changed, they became prooxidant in nature.

Research limitations/implications

In vitro studies have limitations for extrapolation to in vivo and clinical studies.

Practical implications

Such information will be useful in determining optimal concentrations and combinations of antioxidants for reducing rancidity and perhaps as models that could be used to modulate various chronic diseases that are associated with oxidative stress.

Originality/value

Olive oil, along with fruits, vegetables and fish, are important constituents of health promoting diets, such as the Mediterranean diet. Active ingredients include monounsaturated fatty acids, oleic acid and a variety of antioxidants including various polyphenolic compounds.

Citation

Etherton, A.K. and Omaye, S.T. (2015), "Oxidation of olive oil fortified with quercetin, caffeic acid, tyrosol and hydroxytyrosol", Nutrition & Food Science, Vol. 45 No. 3, pp. 493-508. https://doi.org/10.1108/NFS-09-2014-0083