Chemical profiles of five minor olive oil varieties grown in central Tunisia

The aim of the present investigation is to discriminate five minor Tunisian olive cultivars (Hor Kesra, Sredki, Chladmi, Betsijina and Aloui) by studying their sterol and phenol compositions. This is the first study of the chemical composition of virgin olive oils (VOO) from these cultivars. The majority of analytical parameters presented statistically significant differences (P < 0.01). The examined varieties produce excellent oils with a chemical composition within the regulatory limits and an appreciable amount of natural antioxidants. Our results showed that Betsijina oil was characterized by high mean values of total phenols (1400 mg kg1) and oxidative stability (113 h). VOOs studied demonstrate that the differences in phenols (min: 253–max: 1400 mg kg1), tocopherol (139–402 mg kg1), sterols (1039–1567 mg kg1), triterpene dialcohols (19.1–32.4 mg kg1) and triacylglycerols profiles may be explained by genetic factors. Results of PCA and HCA analyses show a good discrimination between varieties according to phenol, triacylglycerol and sterol data. These components seem to be an effective tool to discriminate between the varietie

Virgin olive oil volatile compounds from lipoxygenase and characterization of monovarietal olive oils obtained from different Tunisian mills

The aim of this study was to evidence the differences on the aroma compounds of Chétoui monovarietal olive oils collected from different oil mills from Béja region (Northwestern Tunisia). The volatile compounds of the studied oil samples were separated, identified and quantified, using a HS-SPME coupled to GC-MS. The products of lipoxigenase (LOX) cascade were generally the major components of volatile fraction of olive oil. In this study we are interested to evaluate the C5 and C6 compounds that already been identified as responsible for positive odour properties of olive oil. The C6 compounds were the major components in all virgin olive oil headspaces; they ranged between 94.9 (Slouguia Mill) and 99.3% (Nefza 1 Mill) from the whole LOX products. In addition to the C6 compounds, the headspace of tested olive oils shows a small amount of C5 compounds, between 0.7 and 5.1% of total LOX products. Results demonstrated a large variability in qualitative and quantitative aroma composition according to the oil mill location. Most of the Chétoui oil samples from Béja region revealed high amounts of LOX products. Chétoui cultivar is widely grown in different sites of Béja. It is influenced by the different climatic conditions. The obtained oils strongly differed according to the production area

Traditional Foods in Maghreb: Production and Research Progress

International audienc

Irrigation with treated wastewater affected the minor components of virgin olive oil from cv. Chemlali in Tunisia

Water limitation for agriculture is a problem in many countries and irrigation with treated wastewater (TWW) can be a tool to face the decreasing availability of water for important domestic crops such as olive. Taking into account this aspect, a research was carried out for 13 years in an olive grove (Chemlali cultivar) located in the area of Sfax (Tunisia). Two different irrigation treatments were applied: (a) irrigation with good quality water (GQW) and (b) irrigation with TWW. The main objective of this 13-year study was to verify the effects of the irrigation with TWW vs. GQW on some minor parameters of the virgin olive oil. Many oil parameters significantly increased in the TWW irrigated plot, in particular lutein, total tocopherols, squalene, campesterol and stigmasterol whereas β-carotene, α-tocopherol, δ-tocopherol, β-sitosterol and total sterols decreased with respect to the GQW treatment. Irrigation with TWW can be a possible tool to irrigate olive groves with two positive effects: saving of freshwater and production of olive oil of good quality