Extraction and recovery of capsaicin from scotch bonnet by alkaline-based deep eutectic solvent

Deep eutectic solvents (DESs) have emerged as green alternatives to conventional organic solvents for the efficient extraction of bioactive compounds. In this study, capsaicin was extracted from Capsicum annuum (C. annuum) by ultrasound-assisted extraction using strong to mild acid- and alkaline-based DESs to compare their extraction efficiency with conventional solvent. Strong alkaline-based DESs extract showed the highest capsaicin content (17.58 ± 0.28 mg/g) compared with other DESs, including acid-based DES (12.88 ± 0.11 mg/g) and ethanol (13.85 ± 0.24 mg/g) (p < 0.05) in the screening of DESs. Furthermore, optimization of alkaline-based DES extraction parameters achieved an increased capsaicin content 19.15 mg/g. Macroporous resins (SP850, XAD2, and XAD16N) were used to recover capsaicin from DES extract, and SP850 showed the highest adsorption and recovery ratio of capsaicin. Moreover, the antioxidant potency of the recovered capsaicin was confirmed using radical scavenging assays. This study provides an eco-friendly, novel, efficient extraction method for obtaining capsaicin from C. annuum.