Gas chromatography-mass spectrometry-olfactometry was used for the analysis of volatile compounds and key odorants of three less studied Tunisian olive oil cultivars for the first time. A total of 42 aroma compounds were identified and quantified in extra virgin olive oils. The present study revealed that the most dominant volatiles in olive oil samples qualitatively and quantitatively were aldehydes and alcohols, followed by terpenes and esters. Indeed, chemometric analysis has shown a correlation between chemical compounds and sensory properties. The determination of aroma-active compounds of olive oil samples was carried out using aroma extract dilution analysis. A total of 15 aroma-active compounds were detected in the aromatic extract of extra virgin olive oil, of which 14 were identified. On the basis of the flavor dilution (FD) factor, the most potent aromatic active compound was hexanal (FD = 512) in Fakhari olive oil, (FD = 256) in Touffehi oils, and (FD = 128) in Jemri olive oil.

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In the present paper, two irrigation treatments were applied to olive trees cv. Chemlali: irrigation with treated wastewater (TWW) and with olive mill wastewater (OMW), which was spread at three levels (50, 100, and 200 m(3)/ha). This work is interested in two topics: (1) the influence of different irrigation treatments on olive oil composition and quality and (2) the comparison between OMW and TWW application using different statistical analyses. The obtained variance analysis (ANOVA) has confirmed that there are no significant differences in oil quality indices and flavonoids between the control and treatments amended by OMW or TWW (p > 0.05). However, the irrigation affected some aspects of olive oil composition such as the reduction in palmitic acid (16.32%) and increase in linoleic acid (19.55%). Furthermore, the total phenols and α-tocopherol contents increased significantly following OMW and TWW treatments. Principal component analysis (PCA) and hierarchical cluster analysis (HCA) defined three irrigation groups: OMW 50 and 100 m(3)/ha, OMW 200 m(3)/ha and control, and TWW treatment. The full factorial design revealed that OMW amendment by 100 m(3)/ha is the best irrigation treatment. Thus, the optimal performances in terms of olive oil quality and composition were shown by olive oil extracted from olives grown under irrigation with 100 m(3)/ha of OMW.