Comparative study of olive oil quality from Chemlali Sfax versus Arbequina cultivated in Tunisia

The effects of the geographical region on the behavior of the Arbequina olive cultivar (cv) cultivated in the south of Tunisia (in the arid zone of Sfax) was compared to an autochthonous cultivar (Chemlali Sfax). Various olive parameters were analyzed, such as ripening index, pulp/stone ratio, oil contents, and sensory profiles. Most of the quality indices and fatty acid composition showed significant variations among olive cultivars. Arbequina cv is characterized by high oil yield with a less total phenols and pigments content than Chemlali Sfax cv. Cielab spectrophotometer coordinate L*, b*, and a* values show a great difference in olive oil colors. In spite of their low oleic acid contents, autochthonous cultivar presented a higher induction time (6.82 and 2.68h for Chemlali and Arbequina, respectively) and high contents of phenolic compounds (158.28 and 110.27mg/kg for Chemlali Sfax and Arbequina, respectively). The most important compounds identified were oleuropein aglycon (45.50mg/kg), hydroxytyrosol (3.68mg/kg), 1-acetoxypinoresinol (6.23mg/kg) in Chemlali Sfax oil and hydroxytyrosol glucoside (25.15mg/kg), tyrosol (12.51mg/kg), and oleuropein aglycon (30.60mg/kg) in Arbequina oil. Chemlali Sfax also possessed a very bitter taste, whereas the Arbequina had a sweet taste amongst its attributes. The principal component analysis of the results indicated that the geographical region has significantly affected the olive oil quality.