Phenolics, fatty acids, and biological potential of selected Croatian EVOOs
Nutritional value of extra virgin olive oil is associated with its complex chemical composition. The aim of this study was to determine phenolic secoiridoids in EVOOs from autochthonous Croatian cultivars (Drobnica, Krvavica, Lastovka, and Oblica) by qNMR, to determine simple phenolics by UPLC, as well as to analyse the fatty acid profile, the antioxidant activity and the oxidative stability of selected oils. This is the first study on chemical and biological characterization of selected autochthonous olives varieties. Drobnica EVOO contained the highest amount of total phenols and major secoiridoid derivatives (oleocanthal, oleacein, oleuropein aglycon, and ligstroside aglycon) compared to other oils. The antioxidant activity of Drobnica phenolics was very high by FRAP and copper-induced LDL oxidation assays, while the oxidative stability of Drobnica oil by Rancimat method was very long (23 h). Practical applications: This study represents the contribution to the research of chemical and biological potential of monovarietal extra virgin olive oil from Croatia. EVOOs from selected Croatian autochthonous cultivars had very high phenolic content that is related to high inhibitory rate of copper-induced oxidation of human LDL as well as the long oxidative stability. Drobnica EVOO showed very long oxidative stability. EFSA approved health claim on olive oil polyphenols (EU, 432/2012) and selected Croatian cultivars, especially Drobnica, are of interest due to its high phenolic content and strong biological potential.