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Grains of Tunisian durum wheat varieties (Razzek, Karim, and Om Rabia) were collected from four growing locations (Zaghouan, Jendouba, Kef, and Kairouan). The wheat kernels were evaluated for various chemical and technological quality parameters. The results showed strong effects of growing area and genotype on the chemical compositions of wheat grain samples. These two factors (growing area and genotype) had significant effects on all measured parameters such as the thousand kernel weight, test weight, grain vitreousness, ash content, and gluten and grain-protein levels, but not the fatty acid composition. This study showed that Northern Tunisia (Kef and Jendouba) appears to have a favorable environment for the production of high-quality Razzek durum wheat. Central Tunisia (Kairouan) seems to have the most suitable environment for growing Om Rabia and Karim. It is important to chemically characterize these cultivars in order to select varieties that produce good-quality durum wheat grains which are well adapted to the environmental conditions in Tunisia.

The aim of this work was to characterize extra virgin olive oils (EVOOs) from four cultivars (Arbequina, Chetoui, Neb Jmal and Picholine) cultivated in Northern Tunisia (Borj El Amri) in terms of their phenolic profile. Determination of total phenol content was first performed spectrophotometrically using the Folin–Ciocalteu reagent. The total phenol content of the analyzed EVOOs varied from 77.33 mg GAE kg−1 in ‘Arbequina’ oil to 405 mg GAE kg−1 in ‘Picholine’ oil. Moreover, the polar extracts were analyzed by a rapid and effective Rapid-resolution liquid chromatography coupled to electrospray ionization time-of-flight mass spectrometry (RRLC–ESI-TOF/MS) method, and 48 phenolic compounds belonging to different classes were identified. The results showed significantly quantitative differences observed for all phenolic compounds except for oleuropein that was present only in two cultivars. In all olive oil samples studied, secoiridoids were the most abundant. Deacetoxyoleuropeinaglycone remains the most abundant complex phenol in Picholine (250.39 mg kg−1), Neb Jmal (104.34 mg kg−1) and Arbequina (19.93 mg kg−1) EVOOs, while in Chetoui oil, the oleuropeinaglycone isomer 5 content is the highest with mean value of 381.63 mg kg−1. The application of principal component analysis permitted a good classification of the EVOOs according to their phenolic profiles.

A study on the characterization of Tunisian extra-virgin olive oil varieties produced in their place of origin has been carried out. Due to the influence of the genotype and environmental, agronomic and technological factors on the chemical composition of olive oil and its quality, all the olives studied were collected on the same season, and the oil was obtained under the same processing technique. Several analyses were performed to characterize the different olive oils: free acidity, peroxide value, fatty acid composition, radical scavenging activity, Rancimat assay, pigments content and phenolic compounds by HPLC–MS. In order to evaluate all the results obtained (36 parameters for each variety), different statistical analyses were used to discriminate the extra-virgin olive oil varieties: one-way analysis of variance was performed to check significant differences among cultivars (p ≤ 0.05); PCA was applied to the data showing that variables such as oleic, linoleic, quinic and vanillic acids, apigenin, luteolin, taxifolin, oleuropein aglycon, pinoresinol acetate, elenolic acid and oxidative stability allowed discriminating among the different varieties of extra-virgin olive oil studied. Besides, LDA model was able to classify the samples depending on their geographical origin in Tunisia (North, Centre and South).