CHEMOMETRIC CHARACTERIZATION OF FIVE TUNISIAN VARIETALS OF OLEA EUROPAEA L. OLIVE FRUIT ACCORDING TO DIFFERENT MATURATION INDICES

ABSTRACT The usefulness of some chemical parameters as a tool to discriminate five varietals of olives was evaluated. Fruits were collected from the same orchard in order to eliminate geographical and climatic effects. Biochemical and quality characteristics in the fruits at complete ripeness were also investigated. Results showed that pomological characteristics and fatty acid composition may differ, depending on the variety and ripeness state, which is confirmed by an analysis of variance. A linear trend between mannitol and oil content was observed (r = 0.665; P < 0.001). Jeddaria Chaal olive oil had both the highest triolein (39.33%) and oleic acid value (74.43%). However, Chemlali Chouamekh olive oil showed the highest pigment (59.29 and 26.37 mg/kg of chlorophylls and carotenes, respectively) and α-tocopherol content (201.40 mg/kg). Thus, the cultivars were clearly differentiated in their metabolic behavior and the biochemical characteristics of their oils. Ripening state is used mainly as a guideline to establish the olive harvest time. The present data provide information about the maturation patterns of different cultivars and how it can influence the quality of the final product. PRACTICAL APPLICATIONS This research is strongly oriented to the agronomic application. The obtained results can orient an agronomist to the optimum ripening date of olive fruits with a good amount of oil and a balanced fatty acid composition.