Hydrodistillation time affects dill seed essential oil yield, composition, and bioactivity

Authors: SINTIM, HENRY - University Of Wyoming; BURKHARDT, ANDREW - University Of Wyoming; GAWDE, ARCHANA - University Of Wyoming; Cantrell, Charles; ASTATKIE, TESSEMA - Dalhousie University; OBOUR, AUGUSTINE - University Of Wyoming; ZHELJAZKOV, VALTCHO - University Of Wyoming; SCHLEGEL, VICKI - University Of Nebraska

Submitted to: Industrial Crops and Products
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/30/2014
Publication Date: 11/3/2014
Publication URL: http://handle.nal.usda.gov/10113/62258
Citation: Sintim, H.Y., Burkhardt, A., Gawde, A., Cantrell, C.L., Astatkie, T., Obour, A.E., Zheljazkov, V.D., Schlegel, V. 2014. Hydrodistillation time affects dill seed essential oil yield, composition, and bioactivity. Industrial Crops and Products. 63:190-196.

Interpretive Summary: Dill (Anethum graveolens L.) is an annual herb of the plant family Apiaceae, cultivated for its edible leaves and seeds in most parts of the world. Dill seed has aromatic, carminative, and stimulant properties and is often used whole or ground for flavoring in meats, stews, pastries, and vinegars, and are commonly used as local means to treat a wide range of digestive disorders in many traditional medicines. Both dill herbage and dill seed contain pleasantly scented essential oil. Dill essential oil can relieve pain, stimulate appetite, promote digestion, relieve flatulence, and prevent arteriosclerosis. Countries in the Mediterranean region and Eastern Europe, and Russia and India are major producers of dill essential oil. Dill essential oil is widely used by both the food and pharmaceutical industries. We hypothesized that the chemical constituents of dill seed essential oil are eluted at different times during the hydrodistillation process, resulting in oils with different composition and bioactivity. Dill oil was collected at different hydrodistillation times (HDT, 2, 7, 15, 30, 45, 75, 105, 135, 165, and 195 min). By collecting the essential oil at different time points, it may be possible to obtain dill oil with a distinct and desirable composition. Therefore, the objectives of this work were to evaluate the effect of the duration of HDT time on dill seed oil yield, composition, and bioactivity. Knowledge of this will foster optimization of HDT for extracting dill seed essential oil, especially when certain compounds are desired and/or others must be avoided. This will be applicable for industrial purposes as it will conserve time, energy, resources, and improve quality and yield of dill essential oil.

Technical Abstract: Dill (Anethum graveolens L.) essential oil is widely used by the food and pharmaceutical industries. We hypothesized that the chemical constituents of dill seed essential oil are eluted at different times during the hydrodistillation process, resulting in oils with different composition and bioactivity. Dill oil was collected at different hydrodistillation times (HDT, 2, 7, 15, 30, 45, 75, 105, 135, 165, and 195 min). The control was a non-stop HDT of 195 min. Most of the D-limonene and p-cymenene were eluted during the initial time frames (0-2 and 2-7 min HDT). Most of the carvone and most of the apiole were eluted during the 45-75 min. Most of the trans-dihydrocarvone was eluted during 7-45 min, most of the cis-dihydrocarvone was eluted during 45-165 min HDT. The oil collected at 2 min had the highest antioxidant activity (21.8 µmole Trolox equivalents/g). The regression models developed in this study can be used to predict the composition of dill seed oil eluted at different times and to compare literature reports. The results may assist the essential oil industry to optimize HDT of dill seed and to obtain dill oil with differential compositions and potentially diverse uses from the same batch of seed.