Ultrasound-Assisted Recovery of Chlorogenic Acid From Artichoke (Cynara scolymus L.) Leaves: Process Optimization by Response Surface Methodology and Antioxidant Evaluation of the Optimized Extract.

Artichoke (Cynara scolymus L.) is recognized for its numerous health benefits, attributed mainly to its phenolic compounds, such as cynarin and chlorogenic acid, which have antimicrobial, anti-inflammatory, and antioxidant activities. This study is aimed at enhancing the value of the nonedible parts of the plant by optimizing a method for extracting chlorogenic acid from artichoke leaves. The extraction process of bioactive compound was optimized using the response surface methodology coupled with a Box-Behnken design. A total of 27 experiments were performed, varying three operating parameters: ethanol concentration (from 20% to 70%), sonication time (30 and 45 min), and solid/solvent ratio (1/10 and 1/100 g/mL). The yield of chlorogenic acid was quantified by high-performance liquid chromatography. The results revealed that the optimized conditions were a solid/solvent ratio of 1/10 g/mL, an ethanol concentration of 56.09%, and a sonication duration of 45 min. The maximum yield of chlorogenic acid was determined to be 14.93%. Under the above-mentioned conditions, the antioxidant activity was evaluated in vitro using two methods: DPPH and ABTS radical-scavenging activity. The inhibition concentration 50 (IC50) obtained were 0.230 mg/L for DPPH and 0.237 mg/L for ABTS.