Phenolics, fatty acids, and biological potential of selected Croatian EVOOs

Abstract

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 Extra virgin olive oils (EVOOs) from autochthonous Croatian cultivars (Drobnica, Krvavica, Lastovka, and Oblica) by qNMR, to determine simple phenolics by UPLC, as well as to analyze 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.

Antique Traditional Practice: Phenolic Profile of Virgin Olive Oil Obtained from Fruits Stored in Seawater

“…The determined concentrations of hydroxytyrosol in VOO and VOO-Sea, that amount to 18.2 mg/kg and 12.9 mg/kg, respectively, are generally in the range similar to the values in some Spanish (6.9–72.7 mg/kg of oil) or Italian EVOOs (0.85–36.7 mg/kg of oil) [ 17 , 19 , 20 ], and are even higher than those previously published for Oblica variety (6.2–11.3 mg/kg of oil) [ 11 , 21 , 22 ]. Furthermore, the tyrosol concentration determined in VOO and VOO-Sea (8.10 mg/kg and 7.20 mg/kg respectively) is very similar to the values in the same literature.…”

Characterisation of Monovarietal Olive Oils Obtained from Croatian cvs. Drobnica and Buza during the Ripening Period

“…We found that olive oil from Buza has a significantly higher level of oleic acid than Drobnica, which corresponds with results from the multi-year data ranging from 1992 to 2009 in Istria where the level of oleic acid in the Buza variety was 74% [ 20 ] or near 74% [ 11 ]. In Drobnica, cultivated in Dalmatia, oleic acid was found to be lower (near or under 70%) [ 7 , 8 ].…”

“…This also affected the highest antioxidant activity of Drobnica oil and it’s very long (23 h) oxidative stability as determined by the Rancimat method. Similarly, Dalmatian monovarietal olive oils were analysed in relation to the harvest period (Buhavica, Drobnica, Lastovka and Oblica) [ 8 ]. It was observed that the late harvest contained an extremely high concentration of oleocanthal + oleacein (966 mg/kg) in EVOO from Drobnica, and that oils from Drobnica and Lastovka (Korčula Island, South Dalmatia, position 42°57′31.62′′ N) had the longest oxidative stability (20.95 and 18.65 h, respectively).…”

“…The fruit ripeness of both cultivars is considered as “middle late”, for mixed uses (as table olives and olives for oil extraction). The oils are of high oxidative stability, and their organoleptic characteristics are very appreciated by consumers [ 8 , 9 , 10 ]. Drobnica gives an oil of pronounced bitterness, gentle bitterness intensity, and a somewhat pronounced sweetness.…”

“…More recently, the time of olive harvesting has shifted to early in October when the fruit is green or spotted. Despite existing reports about the ripening of local olive cultivars [ 9 , 11 , 14 , 15 ], and the chemical and sensory characteristics of Croatian olive oils [ 8 , 16 , 17 , 18 , 19 , 20 , 21 , 22 ], these monovarietal oils still are not sufficient investigated.…”