Fennel (Foeniculum vulgare Mill.) is an herb from the Mediterranean region used for flavor and medicine. Sweet fennel is cultivated commonly. Sweet (dulce) and bitter (vulgare) varieties grow wild. Fennel oil is important commercially. Fennel is used, traditionally, for digestive complaints. Fennel fruit is known to be diuretic, analgesic, antipyretic and antioxidant.
The purpose of this study of fennel was to compare the phenolic, flavonoid and antioxidant contents of wild fennel, edible fennel and medicinal fennel from different Mediterranean countries (Italy, Spain, Greece, Turkey and Egypt).
The phenol content of fruits and vegetables correlates with the antioxidant activity. Flavonoids are a type of phenol, making up about 80% of all phenols. Antioxidant activity was evaluated by testing for free radicals, for hydroxyl radicals and for superoxide scavenging activity. The phenolic chemicals found included cryptochlorogenic, chlorogenic, neochlorogenic and rosmarinic acids and the following flavonoids: miquelianin, rutin, eriocitrin and quercetin. The major part of fennel essential oil is estragole.
The wild fennel plants had the highest antioxidant activity, especially those from Italy. Spanish and Greek samples had good antioxidant activity. Edible fennel samples had low radical scavenging activity. The antioxidant activity of medicinal fennel was intermediate between that of wild and of edible fennel.
CONCLUSION: Wild fennel had the highest radical scavenging activity and highest phenol and flavonoid content of all fennels tested. In general, levels found in edible fennel were the lowest and medicinal levels were intermediate. These findings “support the possibility that fennel has protective effects on human health.”
NOTE: It is not unusual for wild varieties of plants to contain the highest levels of beneficial chemicals.
Fennel is on the list for alkaline foods and herbs.
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