Efficient extraction of essential oils from fruits of Pimpinella anisum L. with milk

Essential oils are a composite of many lipophilic and volatile aromatic components. The concentration of essential oils in drugs adds up to 1–2%, in exceptions up to 20%. Their aromatic compounds normally consist of mono- and sesquiterpenes and/or allylbenzenes [1]. The essential oil from fruits of Pimpinella anisum L. mainly consists of the allylbenzene trans-anethol with a concentration of about 80%. Brewing a tea infusion with water seems at first view, due to their lipophilic character, improper to dissolve the essential oils. Looking at milk as a solvent, there are both: an aqueous component and a fatty component, capable of solubilizing any lipophilic parts of the essential oil. In our investigations [2] we produced infusions out of 3g of fruits from Pimpinella anisum L. with water, with low-fat milk (1.5%) and full cream milk (3.5%). After adding carvone as an internal standard and distillation with a Neo-Clavanger-distiller, we measured the amount of essential oil in the infusions with gas-liquid chromatography (GLC). Comparing the aqueous extract with the full cream milky extract, we nearly doubled the concentration of essential oil in the infusion. Further experiments with weighted samples of 1g to 15g of drug material show saturation-effects corresponding to the net weight, with linearly increasing concentrations of solubilized trans-anethol. Especially for children, milky preparations of fruits from Pimpinella anisum or similar drugs like fruits from Foeniculum vulgare may lead to better acceptance in addition to the desired higher amount of ingested essential oils.

References: [1] Wichtl M (2002) Teedrogen und Phytopharmaka. Wiss.Verlagsges. Stuttgart. [2] Bossy A et al. (2005) DAZ 46: 42–50