Analytical evaluation of two monovarietal virgin olive oils cultivated in the south of Tunisia: Jemri‐Bouchouka and Chemlali‐Tataouin cultivars

Abstract

The characterisation of virgin olive oils from two Tunisian cultivars, growing in the Tataouin zone, namely Jemri-Bouchouka, a rare olive cultivar, and Chemlali-Tataouin, was carried out. Several analytical parameters were evaluated; these include quality index, fatty acids, phenolic, chlorophyll, carotenoid, squalene, α-tocopherol compositions and oxidative stability. Jemri-Bouchouka olive oil had the highest value of oleic acid (74.50%) while Chemlali-Tataouin olive oil had the highest value of oleic acid (69.39 %) and also was characterized by a high percentage of palmitic acid (14.75 %) which makes this oil freeze at a low temperature [corrected]. On the other hand, Jemri-Bouchouka oil was characterised by a low phenolic and α-tocopherol content (267.72 mg GAE kg⁻¹ and 278.34 mg kg⁻¹, respectively). Ten phenolic compounds were identified. The main phenols found in the two olive oils were oleuropein aglycon and pinoresinol. All phenolic compounds showed significant correlations with oxidative stability. The analytical parameters of virgin olive oil that were determined in this study were greatly influenced by cultivar.