Antioxidant capacity of extracts from wild and crop plants of the Mediterranean region.

There is an increasing demand for natural antioxidants to replace synthetic additives in the food industry. The present work examines the potential of some wild and cultivated plants from the Mediterranean region as sources of natural antioxidants. Samples of different organs and tissues from each of these species were extracted with aqueous and organic solvents and analyzed for their total hydrosoluble and lipid-soluble antioxidant capacity, measured by the phosphomolybdenum method, and for their content in tocopherols. Our results demonstrate that there is more than a 1000-fold difference among total antioxidants in various plant sources. The highest level of water-soluble antioxidant capacity was found in fruit peel and leaf samples, while seeds presented the highest levels of lipid-soluble antioxidant capacity. Tocopherols were more abundant in leaf samples. Holm oak and olive tree leaves showed the highest yields of alpha-tocopherol. These Mediterranean plant species could be used as a very good source of both water-soluble and lipid-soluble antioxidants, particularly alpha-tocopherol.