Comparison of the Effect of Various Extraction Methods on the Phytochemical Composition and Antioxidant Activity of Thymelaea hirsuta L. aerial parts in Tunisia

摘要

The present study aims to evaluate the effect of extraction methods namely soxhlet and cold maceration on the quality of T. hirsuta extracts, collected from different geographic regions within Tunisia. Hexane, ethyl acetate and methanol were used as solvent for both extraction processes. Yields varied considerably (from 0.61 to 8.11 %) according to sampling region, organic solvent and extraction method. The various chemical contents extracts were estimated by colorimetric methods, revealing important amounts of polyphenols (from 29.37 ±1.34 to 259.63 ± 3.17 mg GAE/g) and flavonoids (from 26.22 ± 6.06 to 163.64 ± 3.32 mg QE/g).The antioxidant activity was measured using the DPPH-radical scavenging, the ABTS-radical scavenging and the ferric reducing antioxidant power (FRAP) assays. The antioxidant analysis showed that the methanol extract obtained by both processes exhibited the uppermost capacity to scavenge free radicals. However, the cold maceration technique leads to the richest extract in phenolic compounds compared to soxhlet method.