American Journal of Food Science and Technology, 2018, Vol. 6, No. 6, 228-236 Available online at http://pubs.sciepub.com/ajfst/6/6/1 ©Science and Education Publishing DOI:10.12691/ajfst-6-6-1 Effects of Geographical Location on Chemical Properties of Zarazi Virgin Olive Oil Produced in the South of Tunisia Sinda El-Gharbi 1,2,* , Meriem Tekaya 1 , Alessandra Bendini 3,4 , Enrico Valli 3,4 , Rosa Palagano 3 , Mohamed Hammami 1 , Tullia Gallina Toschi 3,4 , Beligh Mechri 1 1 Laboratoire de Biochimie, USCR Spectrométrie de Masse, LR-NAFS /LR12ES05"Nutrition –Aliments Fonctionnels et Santé Vasculaire», Faculté de Médecine, université de Monastir, 5019 Monastir, Tunisia 2 Faculty of Science of Gabes, University of Gabes, 6072 Gabes, Tunisia 3 Department of Agricultural and Food Sciences, Alma Mater Studiorum – University of Bologna, Italy 4 Inter-Departmental Centre for Agri-Food Industrial Research, University of Bologna, Italy *Corresponding author: sindagharbi.1@gmail.com Received August 02, 2018; Revised September 11, 2018; Accepted September 26, 2018 Abstract The effects of geographical location on the chemical composition of olive oil of Zarazi cultivar growing in four different regions in the south of Tunisia (Sfax, Tataouin, Matmata and Medenin) were evaluated. Quality indices, oxidative stability, tocopherol content, fatty acid, sterol and phenolic compositions, were analyzed for each oil sample. Significant differences were detected depending on the growing area (p< 0.05). In general, the main secoridoids, were present in higher levels in the oil obtained from olives of Sfax region. Statistical analyses showed that acidic and sterolic compositions of olive oil were significantly modified according to the growing regions. The Principal Component Analysis of the different analyzed compounds indicated that the factor “geographical location” significantly affected olive oil quality, and highlighted the high quality of oil samples of Sfax, in terms of their high oxidative stability and their richness in bioactive compounds. Keywords: fatty acids, geographical location, olive oil, sterols, phenolic compounds Cite This Article: Sinda El-Gharbi, Meriem Tekaya, Alessandra Bendini, Enrico Valli, Rosa Palagano, Mohamed Hammami, Tullia Gallina Toschi, and Beligh Mechri, “Effects of Geographical Location on Chemical Properties of Zarazi Virgin Olive Oil Produced in the South of Tunisia.” American Journal of Food Science and Technology, vol. 6, no. 6 (2018): 228-236. doi: 10.12691/ajfst-6-6-1. 1. Introduction Virgin olive oil (VOO) is considered as the best oil through its sensory, functional and chemical composition, and make it unique among other vegetable oils because it contains essential nutritional elements (antioxidants, vitamins, etc.) [1]. The factors affecting olive oil chemical composition can be clustered into four groups: environmental (soil, climate), agronomic (irrigation, fertilization), cultivation (harvesting, ripeness), and technological factors (post-harvest storage, extraction system, oil storage conditions). These factors currently affect the physico-chemical quality, the sensory characteristics and the chemical composition of the extracted olive oils [2,3]. Moreover, olive oil quality is linked to the olive cultivar and to the geographical locations of the olive cultivar [4]. Polyphenols, which are important minor compounds and main antioxidants in VOO, are one of the basic parameters to be taken into account in the authentication with respect to geographic region and cultivars [5,6]. The fatty acid composition has a key role in the characterization of olive oil. VOO has high contents of monounsaturated fatty acids, mainly oleic acid which ranges from 56% to 84% [7], thus showing great importance, particularly in relation to its effect on cardiovascular system health [8]. The sterol profile, instead, is widely used for the examination of its authenticity because sterols can be considered as its real fingerprint [1]. Only few authors have focused their attention on the location (geographical area, latitude, altitude) of olive tree crops and how it can influence physical, chemical, sensory and nutritional characteristics of the relative oils. Tunisian orchards are dominated by the cultivar population Chemlali occupying 2/3 of Tunisian olive orchard and providing more than 60% of the national production of the olive oil [9]. Nevertheless, there are other secondary varieties specific of local regions such as Zarazi cultivars in the south of Tunisia. Several studies have been performed to classify virgin olive oils from various geographical areas in Tunisia following their different chemical properties [10]. However, there is no study on the effect of geographic location on the chemical composition of Zarazi cultivar, cultivated in the south of Tunisia and appreciated for its high oil content. In this context, the ultimate objective of this study was to investigate the modification of chemical composition of