The Effects of Different Irrigation Treatments on Olive Oil Quality and Composition: A Comparative Study between Treated and Olive Mill Wastewater

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 m3/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 irrig...