Antioxidant activity and phenolic compounds in the edible parts of early and late Italian artichoke (Cynara scolymus L.) varieties

The content of total phenolic compounds (TPC) and chlorogenic acid (CA) and the antioxidant activity in the methanolic extracts of edible parts of three early and two late Italian artichoke (Cynara scolymus L.) varieties were determined and compared. TPC content was determined by the Folin-Ciocalteu reagent and the antioxidant activity by the DPPH method. CA quantification was carried out by HPLC and GC/MS using CA methyl ester as internal standard. Results showed that artichoke varieties differ considerably in their TPC (7.31-13.05 mg/g fresh weight) and CA (1.36-2.46 mg/g fresh weight) content, as well as in their antioxidant activity. No significant correlation was observed between TPC content and DPPH scavenging activity. Boiling the inner bracts of the heads led to a 46% loss of CA.