Metabolite profiling and potential antioxidant activity of sixteen fennel (Foeniculum vulgare Mill.) populations wild-growing in Tunisia

Sixteen wild Foeniculum vulgare Mill. populations native to Tunisia were investigated based on their phenolic profile of methanol extracts of seeds. The antioxidant potential was evaluated using four model systems such us total antioxidant capacity (TAC), DPPH-radical scavenging activity, ABTS test and reducing power assay (RPA). Results showed significant variations on extracts yields, total polyphenol content (TPC), total flavonoid content (TFC) and CTC (condensed tannin content). LC-MS analysis revealed the identification of 26 phenolic compounds. The cirsiliol was reported for the first time as the predominant phenolic compound in all fennel samples with range from 76.16 to 1021.70 mu g/g Dry Extract (DE). The different methanol extracts exhibited strong antioxidant capacities with significant differences among locations. The BeniAyech population showed the highest antiradical capacity with IC50= 23.66 and 7.6 mu g/mL for DPPH and ABTS tests, respectively. However, the strongest iron reduction capacity of the methanol extract from El Alia location has reached an efficacy concentration of EC50= 34.16 mu g/mL similar to the butylatedhydroxytoluene (BHT) standard. This investigation of Tunisian wild fennel showed the great potential of this species as natural source of bioactive antioxidants molecules for food industry. (c) 2022 Published by Elsevier B.V. on behalf of SAAB.