Biochemical characterization of olive oil samples obtained from fruit mixtures and from oil blends of four cultivars grown in Central Tunisia

Blends of olive oils obtained from four cultivars (Olea europaeaL. cv. Chemlali, Chetoui,Oueslati and Koroneiki) were produced by two different methods of blending: processing fruit mixtures ormixing monovarietal oils, using the same proportions of selected cultivars. The obtained blends werebiochemically characterized to evaluate quality, and the two methods were compared. The results indicatedthat the most successful formulations are mainly F8 (60% Chemlali20% Oueslati20% Koroneiki)characterized by the highest contents of phenols and an elevated oxidative stability, and F5 (50%Chemlali50% Koroneiki) containing the highest MUFA level and the highest oxidative stability. Theeffect of the blending process on pigments and volatiles cannot be easily regulated, unlike phenols, fatty acidcomposition and OS, all of which positively correlated to the fruit mass ratio in the blend. Results suggestthat processing fruit mixtures of different cultivars resulted in a better oil quality than that of oils obtained bythe common oil blending method. This blending procedure offers a possibility to modulate the contents ofantioxidants, fatty acids and volatile compounds in virgin olive oil, and therefore, its quality and sensorialcharacteristics.