Search Results

You are looking at 1 - 10 of 55 items for :

  • "essential oil content" x
Clear All
Free access

Valtcho D. Zheljazkov, Tess Astatkie and Ekaterina Jeliazkova

, measured on analytical scale, and kept in a freezer at –5 °C until all distillations were finished. The essential oil content (yield) was calculated by weight, as grams of oil per 100 g of fresh herbage, and expressed as percentage of oil in the fresh

Free access

Denys J. Charles and James E. Simon

Essential oils were extracted from leaves, flowers, and stems of Ocimum basilicurn, O. kilimandscharicum, and O. micranthum by solvent extraction, hydrodistillation, and steam distillation for essential oil content and the oil analyzed by GC and GC/MS for composition. While the yield of essential oil was consistently higher from steam distillation than hydrodistillation, a similar number of compounds was recovered from both hydrodistillation and steam distillation. Though the relative concentration of the major constituents was similar by both methods, the absolute amounts were higher with steam distillation. Essential oil content and composition varied by plant species and plant part. Essential oil content was highest in flowers for O. basilicum and in leaves for O. micranthum. No significant differences were observed in essential oil yield and relative concentration of major constituents using fresh or dry samples and using samples from 75 g to 10 g of dry plant tissue. While minor differences between hydrodistillation and steam distillation were observed, both methods resulted in high yields and good recovery of essential oil constituents. Hydrodistillation is a more-rapid and simpler technique than steam and permits the extraction of essential oil where steam is not accessible.

Free access

Thomas H. Boyle, Lyle E. Craker and James E. Simon

Plants of rosemary [Rosmarinus officinalis L. (Lamiaceae)] were grown in pots containing a soilless (1 sphagnum peat:1 perlite) or soil-based (1 sphagnum peat: 1 perlite:1 field soil) growing medium and fertilized with either 12N-5.2P-12.5K controlled-release fertilizer (CRF) at 9.0 g/pot; constant liquid fertilization (LF) with 20N4.3P-16.7K at 150 mg N/liter; constant LF at 150 mg N/liter, plus CRF at 4.5 g/pot; weekly LF at 150 mg N/liter; or weekly LF at 150 mg N/liter, plus CRF at 4.5 g/pot. Constant LF plus CRF generally reduced plant height and depressed shoot fresh weight relative to other fertilizer regimes. Essential oil content was highest in plants receiving weekly LF. Plants grown in the soil-based mix were shorter, shoot fresh and dry weight tended to be lower, and essential oil yield was higher when compared to plants grown in the soilless mix. Satisfactory growth was obtained in both media when rosemary plants were fertilized with 12N-5.2P-12.5K CRF at 9.0 g/pot or weekly LF with 20N<.3P-16.7K at 150 mg N/liter.

Free access

Natasha Kovatcheva, Valtcho D. Zheljazkov and Tess Astatkie

species under the same ecological conditions have not been reported. The objective of this study was to compare the essential oil content, constituents, and morphologic/phenologic characteristics of 25 varieties, chemotypes, and hybrids belonging to the

Free access

Valtcho D. Zheljazkov, Tess Astatkie, Thomas Horgan and S. Marie Rogers

; MIRC, 2009 ). If the distillation wastewater from an aromatic crop is shown to have growth-promoting effects on peppermint and spearmint or improve their essential oil content, such an extract could be applied to large-scale production systems, bringing

Free access

Valtcho D. Zheljazkov, Charles L. Cantrell, William B. Evans, M. Wayne Ebelhar and Christine Coker

., 1996 ). Crop producers are always looking for high-value specialty crops, and some producers expressed interest in basil as an essential oil crop in Mississippi. However, research on basil productivity, the essential oil content and composition in

Free access

Valtcho D. Zheljazkov, Tess Astatkie and Ekaterina Jeliazkova

increase carvone concentration of ‘Scotch’ spearmint ( Zheljazkov and Astatkie, 2011a ). In another study, the application of MJ had no significant effect on essential oil content of ‘Native’ spearmint ( Zheljazkov et al., 2010b ). In the same study, the

Free access

Valtcho D. Zheljazkov and Tess Astatkie

, 1991 ; Zheljazkov et al., 2010b ). We hypothesized that the length of the DT will have an effect on Japanese cornmint essential oil content and composition. Indeed, various authors used different DTs for extraction of Japanese cornmint, ranging from 60

Free access

Valtcho D. Zheljazkov, Tess Astatkie and Ekaterina Jeliazkova

limonene, eucalyptol, cis-sabinene hydrate, cis-dihydro carvone, beta-bourbonene, and beta-caryophyllene ( Table 2 ). Neither drying duration nor drying condition affected essential oil content (0.254% average in fresh herbage) or the concentration of cis

Free access

Valtcho D. Zheljazkov, Tess Astatkie and Vicki Schlegel

tested in triplicate. Statistical methods. The effect of DT on essential oil content and the concentration and yield of alpha-pinene, beta-pinene, myrcene, delta-3-carene, limonene, cis-ocimene, linalyl anthranilate, alpha-terpinyl acetate, germacrene