Yield, Composition and Antioxidant Capacity of the Essential Oil of Sweet Basil and Holy Basil as Influenced by Distillation Methods.

The profile and bioactivity of essential oil (EO) depends on genetic, environmental, and other factors. We hypothesized that the basil EO may be influenced by the distillation methods. Hence, a study was conducted to evaluate the effect of steam distillation (SD) and hydrodistillation (HD) extraction method on the yield, composition, and bioactivity of EO of sweet basil (Ocimum basilicum) and holy basil (Ocimum tenuiflorum). In both basil species, the EO yield (content) was significantly higher from SD than from HD. There were significant differences in the compounds' concentrations of EO obtained from SD and HD as well, however, the same compounds were identified in the EO from HD and SD. In the EO of O. basilicum, the concentration of 74% of the identified compounds were higher in SD than HD, whereas in the EO of O. tenuiflorum, the concentration of 84% of identified compounds were higher in SD than in HD. However, the concentrations of two of the major compounds of O. basilicum EO (estragole and methyl cinnamate) and a major compound of O. tenuiflorum EO (methyl eugenol) were significantly higher in HD than in SD. The type of distillation did not affect the antioxidant capacity of basil EO within the species. This study demonstrated that the type of distillation may significantly affect oil yield and composition but not the antioxidant capacity of the EO from sweet and holy basil.

Coal-Bed Methane Water Effects on Dill and Its Essential Oils.

Pumping water from coal seams decreases the pressure in the seam and in turn releases trapped methane; this is the most common and economic method of methane extraction. The water that is pumped out is known as "coal-bed methane water" (CBMW), which is high in sodium and other salts. In the past 25 yr, the United States has seen a 16-fold increase in the production of coal bed methane gas, and trillions of cubic meters are yet to be extracted. There is no sustainable disposal method for CBMW, and there are very few studies investigating the effects of this water on plants and their secondary metabolites and on soil properties. This study was conducted to determine the effects of CBMW on soil chemical properties and on the biomass and essential oil yield and composition of dill ( L.). This crop was grown in a greenhouse and was subjected to different levels of CBMW treatment: tap water only; 25% CBMW, 75% tap water; 50% CBMW, 50% tap water; 75% CBMW, 25% tap water; and 100% CBMW. The major dill oil constituents, limonene and α-phellandrene, were not affected by the treatments; however, the concentration of dill ether increased with increasing CBMW levels, whereas the concentration of carvone decreased. In soil, sodium level significantly increased with increasing level of treatment, but pH and cation exchange capacity were not much affected. Coal bed methane water could be used for irrigation of dill for one growing season, but longer-term studies may be needed to clarify the long-term effects on soil and plant.

Method for Attaining Caraway Seed Oil Fractions with Different Composition.

Caraway (Carum carvi L.) is a medicinal and aromatic plant; its seeds (fruits) are used as spice and they contain essential oils. We hypothesized that by collecting caraway oil at different time points during the extraction process, we could obtain oil fractions with distinct chemical composition. A hydrodistillation time (HDT) study was conducted to test the hypothesis. The caraway seed oil fractions were collected at eight different HDT (at 0 - 2, 2 - 7, 7 - 15, 15 - 30, 30 - 45, 45 - 75, 75 - 105, and 105 - 135 min). Additionally, a non-stop HD for 135 min was conducted as a control. Most of the oil was eluted early in the HD process. The non-stop HDT treatment yielded 2.76% oil by weight. Of the 24 essential oil constituents, limonene (77 - 19% of the total oil) and carvone (20 - 79%) were the major ones. Other constituents included myrcene (0.72 - 0.16%), trans-carveol (0.07 - 0.39%), and ß-caryophyllene (0.07 - 0.24%). Caraway seed oil with higher concentration of limonene can be obtained by sampling oil fractions early in HD process; conversely, oil with high concentration of carvone can be obtained by excluding the fractions eluted early in the HD process. We demonstrated a method of obtaining caraway seed oil fractions with various and unique composition. These novel oil fractions with unique composition are not commercially available and could have much wider potential uses, and also target different markets compared to the typical caraway essential oil.