Olive antioxidants under climatic conditions

Abstract

Climate change has become a widespread serious phenomenon. Its effects are related to variability in local climates rather than in global climatic patterns. Mediterranean countries are the most concerned where olive tree constitutes one of the most dynamic cultivations. This work focuses on the research for new indicators of the adaptation of the olive tree to several climatic conditions. ‘Chemlali’ and ‘Chetoui’ represent the primary Tunisian olive tree cultivars. To adapt to different climatic conditions characterizing the north, the center and the south of the country (superior semiarid, inferior semiarid and inferior arid respectively), these varieties synthesize many interesting compounds that have been screened and compared. Indeed, the methanolic extracts from ‘Chemlali’ and ‘Chetoui’ leaves have been tested for their antioxidant activities. The chemical compositions of the extracts have been quantified in antioxidants. Both ‘Chemlali’ and ‘Chetoui’ exhibited a significant antioxidant activity, reaching 90%. However, Chemlali activity was more important in the inferior semiarid (80%) and in the inferior arid (70%), while ‘Chetoui’ activity was more significant in the superior semiarid and in the inferior arid. Total phenols of ‘Chemlali’ showed a triple content in the inferior arid comparatively to the superior semiarid. Additionally, flavonoids, o-diphenols, saponin and carotenoids of ‘Chemlali’ increased significantly in this area as opposed to those of ‘Chetoui’. 2(3H) 5-methyl furanone, 4-vinyl methoxyphenol, and hexadecanoic acid known for their antioxidant activity and many others have been identified in these varieties.