This study aimed to optimize the extraction of phenolic compounds from the cultivated species Opuntia ficus-indica (L.) Mill. (OFI) and the wild species Opuntia stricta (Haw.) Haw. (OS) peels aqueous extract and to evaluate their antioxidant potential. Box-Behnken experimental design and Response Surface Methodology (RSM) were used to study the effects of extraction parameters (Temperature, sample to solvent ratio and time). The total phenolic compounds (TPC) varied between 7620.43-9973.90 mg GAE/100 g DM for OFI and 485.04-652.38 mg GAE/100 g DM for OS. The models showed high coefficients of determination (R² = 0.950 for OFI and 0.905 for OS), ensuring their adequacy. Optimal conditions were found at 90 °C, 0.55 g/100 mL, and 14.33 min for OFI and 64.07 °C, 0.5 g/100 mL, and 6.17 min for OS, leading to 10002.63 and 621.02 mg GAE/100 g DM, respectively. Antioxidant assays indicated that OFI showed higher Trolox equivalent antioxidant capacity (4040.69 mg TE/100 g DM) and ferric reducing power (5140.55 mg TE/100 g DM), while OS showed higher nitric oxide scavenging activity (51.93-%). UV-Vis and FTIR analysis confirmed the presence of phenolics and other bioactive molecules in both extracts. Opuntia peels are underexploited sources of phenolic antioxidants, with promising opportunities for valorization in functional food and health-related applications.
Hamadache et al. (2026) studied this question.