Characterization of 3,4-DHPEA-EDA oxidation products in virgin olive oil by high performance liquid chromatography coupled with mass spectrometry.

Secoiridoid derivatives are the most important antioxidants of virgin olive oil (VOO), and their oxidation products could be used as molecular markers of VOO freshness to define the VOO autoxidation state. The aim of this research was to characterise the dialdehydic form of decarboxymethyl elenolic acid linked to hydroxytyrosol (3,4-DHPEA-EDA) oxidation products to find analytical indicators that could be used as early evaluation index of the VOO autoxidation state. 3,4-DHPEA-EDA was oxidised by enzymatic and Fenton reactions. Terpenic structure oxidation products accumulated in VOO during the autoxidation process, thus they may be used as early evaluation index of the VOO autoxidation state before fatty acids oxidation.