Comparative chemical composition and bioactivity of Opuntia ficus indica Sanguigna and Surfarina seed oils obtained by traditional and ultrasound assisted extraction procedure

This study investigates the seed oils obtained from two different varieties of Opuntia ficus‐indica (Sanguigna and Surfarina) growing in Sicily, Italy. Soxhlet and ultrasound‐assisted extraction procedures are used to obtain the seed oils. The fatty acid profile, γ‐tocopherols, carotenoid content, and the bioactivity in terms of the antioxidant effects (using ABTS, DPPH, FRAP, and β‐carotene bleaching tests), and carbohydrate‐hydrolysing enzyme inhibitory activity (α‐amylase and α‐glucosidase) are determined. The extraction procedure does not significantly affect the fatty acid composition of the oil, but it does affect the tocopherol and carotenoid contents, as well as the antioxidant and inhibitory activities. All the oil samples are rich in polyunsaturated fatty acids, especially linoleic, and oleic acids. Soxhlet extraction proves to be the best extraction procedure to enrich the oils in γ‐tocopherol. Relative antioxidant capacity index (RACI) and global antioxidant score (GAS) analyses are applied to evaluate the antioxidant potential of the Sanguigna variety oil extracted with the Soxhlet apparatus that is shown to be the most active. The same oil also shows the highest α‐amylase inhibitory activity (IC50 value of 40.9 μg mL−1), which is better than that reported for acarbose used as a positive control.