Geographical Discrimination of Virgin Olive Oils from the Tunisian Coasts by Combining Fatty Acids and Phenolic Acids Profiles within a Multivariate Analysis.

Abstract

Virgin olive oils extracted from three principal Tunisian olive cultivars (Chemlali, Chetoui and Zarrazi) and coming from four different regions (Sfax, Beja, Gabes and Medenine) along the Tunisian costs were analysed. The quality indices as well as fatty acids and phenolic acids content of oil samples were examined using univariate and multivariate statistical analysis. The finding demonstrated that significant differences (p < 0.05) were found in quality indices between the different cultivars and that fatty acid content is the most informative in discriminating olive oils from production sites that are different by geographical and climatic parameters. In fact, southern cultivars (Zarrazi Gabes and Zarrazi Medenine) have the best fatty acid combination according to their oxidative effect. Besides, phenolic acids content was not useful in discriminating olive oil samples and could depend not only on geographic location but also on olive variety and agronomic practices. Nevertheless, Principal Component Analysis allowed us to highlight the Chemlali Beja olive oil for its interesting oxidative stability, fatty acid composition and its richness in phenolic acids content.