Botanical Profile
Note: Bitter fennel and sweet fennel have different quality and essential-oil profiles.
Fennel is one of the classic aromatic plants of the Apiaceae from the Mediterranean region. The plant has been known since antiquity as a spice, vegetable, tea and medicinal plant.
Foeniculum vulgare Mill. is a usually perennial, tall-growing plant with strong, grooved stems, finely thread-like divided leaves and yellow umbels. The flowers develop into aromatic schizocarps, which are the most important pharmacognostic plant part. Fennel prefers warm, sunny sites and well-drained soils. Botanically important is the distinction between bitter fennel and sweet fennel. The two forms differ in aroma profile and essential-oil composition; this differentiation is also reflected in pharmacopoeial monographs.
Phytochemistry
Fennel fruits are characterised particularly by essential oil. Characteristic constituents include trans-anethole, fenchone, estragole, limonene, alpha-pinene and other monoterpenes or phenylpropanoids. Bitter fennel typically contains higher proportions of fenchone, whereas sweet fennel is more strongly characterised by trans-anethole. The fruits also contain flavonoids, phenolic acids, fixed oil, proteins, carbohydrates and minerals. Identity, purity, essential-oil content and chromatographic profiles of marker constituents are relevant to quality assessment.
Traditional Uses
Fennel has a long Mediterranean and European tradition as a spice and tea plant. Ancient, medieval and early-modern sources regularly describe the aromatic fruits. EMA/HMPC, WHO, ESCOP and the European Pharmacopoeia treat fennel as a distinct herbal-drug context. Documented traditional contexts concern primarily aromatic fruit drugs, tea preparations and classic digestive and respiratory contexts.
Current Research
Modern research investigates the chemical variability of fennel fruits, analytical characterisation of essential-oil profiles and assessment of individual aroma compounds. Chromatographic studies compare bitter and sweet fennel as well as origins from different cultivation regions. Further topics include storage stability, processing conditions, authenticity and possible adulteration. Estragole-containing aromatic plants are assessed in the literature with differentiation between the isolated substance, traditional herbal drug and exposure.
Sources
- EMA/HMPC: European Union herbal monograph on Foeniculum vulgare Miller, fructus
- WHO: WHO Monographs on Selected Medicinal Plants – Foeniculi fructus
- ESCOP: ESCOP Monographs – Foeniculi fructus
- European Pharmacopoeia: Foeniculi amari fructus / Foeniculi dulcis fructus
- Standard reference: Wichtl M. Teedrogen und Phytopharmaka – Fenchel
Notice
The information presented in this botanical profile has been compiled to the best of our knowledge and belief from botanical, phytochemical, historical and scientific sources. It is intended solely for general professional information and initial orientation.
The content does not constitute an assurance of specific properties, effects, qualities or possible uses of products or extracts. In particular, it does not constitute a guarantee, a statement of suitability, or a statement regarding marketability, permissibility or usability in specific applications or markets.
Assessment of the suitability of a raw material or extract for a particular intended use, as well as compliance with all applicable legal and regulatory requirements, is the sole responsibility of the respective user.