Oleoresin Fennel

Fennel oleoresin is prepared by solvent extraction of whole seeds and normally contains a volatile oil of 50% or a guaranteed content in the range of 52-58%. Only small quantities are produced for specific uses as it is not a substitute for fennel oil. Chemical analysis by Barazani et al. (2002) of the volatile fraction of oleoresins from fruits of seven natural populations of F. vulgare var. vulgare (bitter fennel) from the wild and after cultivation indicated the presence of two groups of populations. Chemotypic differentiation (relative contents of estragole and trans-anethole) or phenotypic plasticity increases within-species chemical variability, but the specific ecological roles of these essential oils remain to be uncovered. 

Chlorophylls are also present in many oleoresins. By fractionation of fennel oil in two separators in series, the pigments precipitate in the first separator [80]. The effects of the extraction parameters on chlorophyll concentration are shown in Table 9.6-4. Increasing extraction pressure and/or temperature favour the dissolution of the pigments. 

Sankarikutty, B., Sumathykutty, M.A., Bhat, A.V. and Mathew, A.C. (1978) Studies on extractions of oils and oleoresins from cumin, fennel and fenugreek. Indian Arecanut, Spices and Cocoa Journal 2(2), 25-30. 

Oleoresin Fennel Obtained by the solvent extraction of the dried fruit of Foeniculum vulgare P. Miller (Fam. Umbelliferae) as a brown-green liquid. 

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