Phytochemical profiling and in vitro biological activities of Opuntia ficus-indica oil extracted by different methods

Abstract Opuntia ficus-indica (L.) Mill., a prominent member of the Cactaceae, possesses notable economic, medicinal, and cosmetic relevance. This study characterizes the seed oil of O. ficus-indica, assessing its phytochemical profile, antioxidant capacity, and antimicrobial activity. Oil was extracted from seeds using three methods—Soxhlet, maceration, and ultrasound-assisted extraction and subjected to fatty acid profiling by gas chromatography–mass spectrometry (GC–MS). Approximately thirty bioactive compounds were identified, including fatty acids, carboxylic acids, aldehydes, and ketones. The physicochemical properties of each extract were determined (specific gravity, refractive index, acid value, peroxide value, and moisture content). Antioxidant activity was evaluated using ferric reducing antioxidant power (FRAP) and Ferric-bipyridine reducing capacity of total antioxidants (FBRC) assays, with results expressed as mg gallic acid equivalents (GAE) per g oil. Among the extracts, the maceration method yielded the strongest antioxidant performance (FBRC: 6.00 ± 0.15 mg GAE g−1; FRAP: 6.21 ± 0.12 mg GAE g−1). Antimicrobial activity was tested against representative Gram-positive bacteria (Staphylococcus aureus and Staphylococcus epidermidis) and Candida albicans using a disc diffusion assay, revealing the largest inhibition zones for the maceration-derived oil (9.7 ± 0.3 mm, 8.6 ± 0.2 mm, and 12 ± 0.6, respectively). Overall, the seed oil exhibits a rich phytochemical composition and substantial antioxidant and antimicrobial activities, underscoring its potential for pharmaceutical and cosmetic applications.