Αntioxidant activity of Cynara scolymus L. and Cynara cardunculus L. extracts obtained by different extraction techniques

Extracts of different parts (heads, bracts and stems) of Cynara cardunculus L. (cardoon) and Cynara scolymus L. (globe artichoke), obtained by two different extraction techniques (Ultrasound-Assisted Extraction (UAE) and classical extraction (CE)) were examined and compared for their total phenolic content (TPC) and their antioxidant activity. Moreover, infusions of the plant's parts were also analysed and compared to aforementioned samples. Results showed that cardoon's heads extract (obtained by Ultrasound-Assisted Extraction) displayed the highest TPC values (1.57 mg Gallic Acid Equivalents (GAE) g−1 fresh weight (fw)), the highest DPPH• scavenging activity (IC50; 0.91 mg ml−1) and the highest ABTS•+ radical scavenging capacity (2.08 mg Trolox Equivalents (TE) g−1 fw) compared to infusions and other extracts studied. Moreover, Ultrasound-Assisted Extraction technique proved to be more appropriate and effective for the extraction of antiradical and phenolic compounds.