Seasonal variation of fatty acid composition, tocopherol content and antioxidant activity of lipid extracts from Centaurea sp.

The changes in fatty acid (FA) composition, and total tocopherol content (TTC) of leaves, roots and roots' bark of Cenaurea sp. grown on the Algerian coast were studied. Moreover, the change within the same season in antioxidant activity of lipid fractions was also measured using the DPPH free radical scavenging activity assay. Results showed quantitative and qualitative changes of the contents of saturated, monounsaturated, polyunsaturated fatty acids and TTC from January until June with different patterns for the different plant parts. The highest TTC were obtained for both mots and roots' bark, and changed differently with the month of collection. The antioxidant IC50 values also showed different pattern changes during the season for roots and mots' bark. Cluster analysis using Agglomerative Hierarchical Clustering showed differences in FA amounts for C18:2 and C18:3 between mots' bark and both roots and leaves parts, which were totally independent of the month of collection.