Evaluation of the ‘antioxidant power’ of olive oils based on a FIA system with amperometric detection

Abstract

A new method for the evaluation of the ‘total antioxidant power’ of olive oils, based on a flow injection analysis system with electrochemical detection, is described. It represents an attractive alternative to the mostly used Rancimat method since it is based on the chemical structure of antioxidants and does not require the manipulation of several parameters, such as temperature and oxygen pressure, to accelerate oil oxidation. The proposed procedure is simple, rapid, allows a throughput of 90 samples h^–1 and provides a good precision: an RSD of 3.5% was obtained for caffeic acid at the concentration level of 5 mg L^–1 (n = 12). A comparison of the proposed procedure with two other methods (Rancimat method and ABTS^•+ decoloration assay) was performed to investigate the applicability and limitations of the proposed method.