Influence of Irrigation With Moderate Saline Water on “Chemlali” Extra Virgin Olive Oil Composition and Quality

Abstract

The main goal of this study was to investigate the effects of moderate saline water irrigation in the “Chemlali” olive cultivar grown in Sfax, an arid region of Tunisia, on the composition and quality of the resultant virgin olive oil in comparison to a control plot grown under rain‐fed conditions. Free acidity, peroxide value, specific ultraviolet absorbance (K232, K270), fatty acid composition, induction time, total polyphenol and total chlorophyll contents were determined and reported. The irrigation did not affect free acidity and peroxide value. Whereas, specific ultraviolet absorbance (K232, K270), fatty acid composition, induction time, total polyphenol and total chlorophyll contents were affected by irrigation. Rain‐fed virgin olive oils showed a statistically significant higher content of oleic and linoleic acids. Virgin olive oils extracted from moderate saline water irrigated trees had higher contents of palmitic, palmitoleic, stearic and linolenic acids and a longer shelf‐life. A positive correlation was noted between polyphenol content and oxidative stability. PRACTICAL APPLICATIONS Olive trees are quite widespread in the south of Tunisia. They grow in semi‐arid environments. It is a species with high resistance to drought. However, irrigation allows productivity to increase in olive growing areas where rainfall is scarce. Irrigation is a determinant parameter for olive oil quality. In fact, high olive oil quality can not be obtained from olive fruit suffering from a high degree of water stress. The main purposes of this paper are to investigate the effects of moderate saline water on the commercial quality, the fatty acid composition, and the induction time, total polyphenol and total chlorophyll contents of “Chemlali” virgin olive oil in Tunisia.

Influence of Irrigation Regimes on Quality Attributes of Olive Oils from Two Varieties Growing in Lebanon

“…The significant decrease of oxidative stability with irrigation can be explained by the parallel decrease in total phenols, in accordance with findings of previous studies [45,46].…”

Long-terms effects of irrigation with treated municipal wastewater on soil, yield and olive oil quality

“…Under Mediterranean climate, where olive tree is the most cultivated crop, the limited water resources and the increased need for good water quality for urban and industrial sector uses, led to the use of nonconventional water sources: agricultural drainage water, brackish or saline water and industrial or municipal wastewater for agricultural irrigation particularly under actual conditions of rainfall scarcity. The reuse of treated wastewater (TWW) in agriculture could be among the management practices to promote olive tree extension and cultivation at least under described experimental conditions in the south of Tunisia as reported by several studies (Bedbabis et al, 2009(Bedbabis et al, , 2010aBen Rouina et al, 2011). In Tunisia, this practice is actually more and more extended.…”

“…• provides a reliable source of water supply to farmers and nutrients source for crop production (Jimenez-Cisneros, 1995); • conserves nutrients, thereby reducing the need for chemical fertilizers (Gil and Ulloa, 1997); • increases crop yields and returns from farming also if applied on olive orchards (Bedbabis et al, 2009(Bedbabis et al, , 2010aBen Rouina et al, 2011); is a low-cost method for sanitary disposal of municipal wastewater. However, application of TWW can have some risks either for agriculture products or soil properties (Yadav et al, 2002;Tarchouna et al, 2010 ;Vivaldi et al, 2013).…”

“…Several studies have focused on the effects of irrigation with treated wastewater and the application of olive mill wastewater and moderate saline water on soil chemical properties (Al-Absi et al, 2009;Mechri et al, 2011;Bedbabis et al, 2010aBedbabis et al, , 2014 and little information is known about the effects of TWW on chemical properties of a cultivated sandy-silty soil. Studies on the effect of TWW on olive's growth, productivity and oil quality in Tunisia are scarce (Bedbabis et al, 2009(Bedbabis et al, , 2010aBen Rouina et al, 2011).…”

“…Studies on the effect of TWW on olive's growth, productivity and oil quality in Tunisia are scarce (Bedbabis et al, 2009(Bedbabis et al, , 2010aBen Rouina et al, 2011). The aim of this study was to assess the effect of TWW in a "Chemlali" olive orchard on soil characteristics, olive yield and VOO quality.…”