Effect of the growing area conditions on differentiation between Chemlali and Chetoui olive oils

This paper reports a discrimination study based on the antioxidant compounds, oxidative stability, aroma and sensory profiles of virgin olive oils from the main Tunisian cultivars, Chemlali and Chetoui, grown in two different locations, north and south Tunisia, with important differences in altitude, latitude and climatic conditions. There were significant differences between the oils from both cultivars when grown in the different environments. At higher altitude, the oils showed a greater amount of oleic acid, phenols and a higher stability, whilst in the open the oils had higher saturated and linoleic acid content. Aroma profiles were also influenced by the pedoclimatic conditions; hence, oils from the South had the highest whereas varieties from the North were higher in (E)-3-hexenyl ace-level of (E)-2-hexenal and 1-hexanol, tate and hexyl acetate. In general, and independently,of the growing area conditions, oils from Chetoui olives had higher levels of antioxidants, greater oxidative stability, higher antiradical activities and more marked intensity of bitterness. These results can be used to discriminate and to characterise the Chemlali and Chetoui olive oils from each region. (C) 2009 Published by Elsevier Ltd.