Microwave assisted extraction of chlorogenic acid from sunflower seed meal using natural deep eutectic solvent based on COSMO-RS design

Sunflower seed meal is a rich source of chlorogenic acid (CGA). In this work, the conductor-like screening model for realistic solvation (COSMO-RS) was used to assist in identifying the optimal natural deep eutectic solvents (NADESs) for the extraction of CGA from the sunflower seed meal. A total of 20 hydrogen bond donors (HBDs) and 10 hydrogen bond acceptors (HBAs) at different molar ratios resulting in 600 NADESs were screened via the COSMO-RS model by calculating the infinite dilution activity coefficients of CGA. The results showed that the solvent composed of choline chloride (ChCl) and urea at a molar ratio of 2:1 had the highest extraction rate of 25.92 mg g −1 for CGA. Additionally, ChCl-Urea (2:1) was chosen as the solvent in response surface methodology (RSM) to optimize the microwave assisted NADES extraction parameters, including liquid-solid ratio, microwave power, temperature and irradiation time, yielding a CGA content of 26.39 mg g −1 . Furthermore, the antioxidant activities of the CGA extract using NADES were determined, which exhibited better DPPH, ABTS radicals scavenging abilities and ferric reducing antioxidant power (FRAP). Therefore, COSMO-RS and RSM can serve as effective techniques for screening NADESs and optimizing extraction processes, thereby expanding the application potential of NADES in extracting various bioactive compounds.