Deep eutectic solvent-assisted ultrasound extraction of Aronia melanocarpa anthocyanins: efficiency, stability, and molecular interaction mechanisms.

Aronia melanocarpa is rich in anthocyanins, requiring efficient and stable extraction methods for fruit and pomace valorization. This study optimized and compared three ultrasound-assisted extraction methods-ethanol (UAE-ET), aqueous two-phase system (UAE-ATPS), and deep eutectic solvent (UAE-DES)-for Aronia melanocarpa anthocyanins (AA) extraction. Under optimized conditions, UAE-ET and UAE-ATPS yielded total anthocyanin content (TAC) of 14.98 and 12.67 mg/g, versus 16.63 and 16.59 mg/g for UAE-DES (UAE-DES > UAE-ET > UAE-ATPS), representing increases of >10.76% (vs. UAE-ET) and >30.96% (vs. UAE-ATPS), respectively. Cyanidin-3-O-galactoside (68.09-73.73%) and cyanidin-3-O-arabinoside (18.95-25.16%) dominated the profile (>90%). UAE-DES extracts exhibited superior color intensity (3.86 and 3.99), a degradation index 12.5% lower than UAE-ET, and enhanced thermal stability (44.84-50.00% retention at 80 °C, k = 0.1171), along with over 2.06-fold higher antioxidant activity than UAE-ET. DES forms hydrogen bonds with anthocyanins, enhancing extraction and stability. These findings confirm DES as an efficient stabilizing medium for AA, supporting its application in high-value anthocyanin products.