Phenolic extraction from prickly pear peels using deep eutectic solvents with macrocyclic enhancers

The study valorizes prickly pear peels, traditionally considered agro-waste, as a source of phenolic antioxidants using an eco-friendly extraction method. Natural deep eutectic solvents (NaDESs) combined with ultrasound-assisted extraction were optimized via response surface methodology to maximize phenolic recovery (80 % v/v choline chloride-citric acid NaDES in water, 30 mL/g solvent-to-solid ratio, 16-min extraction time). HPLC analysis identified catechin, myricetin, rutin, and gallic acid. To improve extraction efficiency, macrocyclic additives (cyclodextrins, CDs, and, for the first time, cyclofructans, CFs) were incorporated into the extraction medium. A systematic comparison of natural and derivatized CDs was also performed to address gaps in the literature. Method greenness and NaDES recyclability were validated using AGREE metrics. Chemometric analysis enabled the classification of samples according to botanical and geographical origin based on phenolic profiles. These results demonstrate an efficient, sustainable strategy for the recovery of valuable compounds applicable to natural product authentication, traceability, and development.