Molecular characterization of Dalmatian cultivars and the influence of the olive fruit harvest period on chemical profile, sensory characteristics and oil oxidative stability

Abstract

Four Dalmatian autochthonous olive cultivars (Buhavica, Drobnica, Lastovka and Oblica) were molecularly characterized by analyzing length variability of genomic DNA sequences encompassing 15 microsatellite repeats. Furthermore, several important parameters of olive oils were analyzed in relation to the harvest period. An analysis of major phenolics secoiridoids was done by qNMR, while the fatty acid profile of oils and squalene content was determined by GC–FID. Oxidative stability was evaluated by the Rancimat method and sensory evaluation was carried out by a trained professional panel. The results indicate that the effect of the harvest period on the phenolic profile of oils depends on the olive cultivar and is related to its genetic profile. Drobnica oil from the late harvest contained an extremely high concentration of oleocanthal + oleacein (966 mg/kg). The longest oxidative stability was achieved by Drobnica and Lastovka oils from the early harvest period (20.95 and 18.65 h). Squalene had no effect on the oil oxidative stability. This study shows that the content of phenolic secoiridoids depends mainly on the cultivar. In addition, some cultivars, such as Drobnica did not show significant change of phenolic secoiridoids content in relation to the harvest period.