Total polyphenol content and antioxidant activity among clones of two sicilian globe artichoke landraces

The globe artichoke is a herbaceous perennial plant native to the Mediterranean Basin, where it has an important economic role in agriculture. In Sicily (South Italy), two landraces, 'Spinoso di Palermo' and 'Violetto di Sicilia' have dominated production, thanks largely to their early flowering habit and acceptability to consumers, but recently they are threatened by the introduction of exotic germplasm as vegetative propagated cultivars and seed-propagated F1 hybrids. Therefore, the characterization of autochthonous landraces represents both a base for the selection of elite clones and a means of implementing in situ conservation. In this respect, we evaluated the total polyphenol content and the antioxidant activity in the receptacle (edible part) and in the waste material (bracts, leaves and floral stem) within a set of globe artichoke clones selected from the population of 'Spinoso di Palermo' (namely clone IV, V and VI) and 'Violetto di Sicilia' (namely clone B3, C1 and S1). It was interesting to note the high total polyphenol content (9.4 g of chlorogenic acid equivalent kg-1 of fresh matter) and antioxidant activity (86.5%) in the receptacle of the clone VI, making it suitable for fresh consumption. On the contrary, due to its low total polyphenol content (3.8 g of chlorogenic acid equivalent kg-1 of fresh matter) in the receptacle, the clone S1 may be better destined to food processing. Overall, the high total polyphenol content found in the waste material may represent an added economic value if exploited for the extraction of these compounds. In conclusion, we have demonstrated that the clonal selection may be a useful way for enhancing current landraces with regards to the polyphenol content and antioxidant activity.