Essential Oil Glands Research Articles

Effects of Electrolyte Concentration and Ultrasound Pretreatment on Ohmic-Assisted Hydrodistillation of Essential Oils from Mentha piperita L.

Abstract In this study, the effects of salt concentration (1, 3 and 6% w/v) and ultrasound pretreatment (50 W for 5, 10 and 15 minutes) on extraction parameters and extracted essential oil from peppermint by ohmic-assisted hydrodistillation (OAHD), a recently innovated extraction technique, have been studied. The results showed that salt concentration significantly affected the extraction parameters of OAHD, while ultrasound pretreatment had negligible effect. Sudden eruption of essential oil glands was observed in scanning electron micrographs of all OAHDs mint leaves. GC-MS analysis did not indicate any noticeable change in the compounds of all the extracted essential oils. The results of this study showed that increase of electrolyte concentration could speed up OAHD process without any adverse effect on essential oil quality, while ultrasound pretreatment neither reduced process time nor increased extraction yield of OAHD.

Features of micromorphological structure of medicinal hyssop

Micromorphological peculiarities of the structure of vegetative and generative organs of Hyssopus officinalis were analyzed. The epidermis of H. officinalis reveals diacyctic stomata and external outgrowths: glandular and covering trichomes, as well as peltate essential oil glands. Capitate and bent indumentary (covering) trichomes occur on the stem, while on the leaves peltate glands, conical and bent uni- and multicellular trichomes were observed. On the calyx, in the midrib region, there are peltate glands while the ribs are densely covered with indumentary and glandular trichomes. The corolla’s adaxial surface is covered with long indumentary trichomes, with sparse peltate glands occurring on the margins. The highest density of essential oil peltate glands is found on the adaxial surface of the calyx upper lip (15.8±2.54 pcs./mm2) and on the leaf abaxial surface (13.6±2.40 pcs./mm2). Glands with the largest diameter (47.82±2.82 μm) are located on the leaf adaxial surface.

Genetic structure and differentiation among oregano [Origanum vulgare subsp. glandulosum (Desf.) Ietswaart] provenances from North Africa: bioinformatic approaches cause systematic bias

Thirteen simple sequence repeat (SSR) markers developed from expressed sequence tags (ESTs) of essential oil glands of Origanum vulgare were previously evaluated. These EST-SSR loci were analyzed to study the genetic diversity and differentiation of Origanum vulgare subsp. glandulosum, an endemic species of Tunisia. The study was performed on five natural populations from the Maghreb regions (North Africa) from northern Tunisia (Sejnane, Krib, Bargou, Zaghouan and Nefza). Two other subspecies of O. vulgare were used as out-group. These are O. vulgare subsp. hirtum (from USA) and O. vulgare subsp. vulgare (from Italy). A total of 60 alleles were detected in the seven populations studied. The number of alleles per locus ranged from 2 to 9. This analysis revealed that the unbiased expected heterozygosity (0.327) is higher than the observed heterozygosity (0.242), reflecting a deficit in heterozygosity in the total population. Only the Sejnane population has an excess of heterozygosity. The differentiation between Tunisian populations is highly significant and indicates the presence of a structure between these populations. However, the indexes of genetic differentiation (FST) values are low and vary between 0.048 and 0.115 which indicate the presence of a weak structure. The value of the FST between Nefza and Krib is not significant, reflecting the absence of genetic structure between them. The value of gene flow between these two populations is the most important (27.34), showing a substantial exchange of genes or genomic regions between them. The migration of genes is less important among the other Tunisian populations. Genetic structuring according to the geographical origin of Tunisian populations is low but still exists, which allows concluding the presence of a single complex gene pool.

Http://www.omicsonline.org/open-access/antigenic-characterisation-of-tenacibaculum-maritimum-isolates-fromsea-bass-dicentrarchus-labrax-l-farmed-on-the-aegean-sea-coasts-2155-9546-1000408.php?aid=69366

Microwave steam distillation (MSD) is an advanced steam distillation (SD) technique utilizing a microwave oven in the extraction process. MSD of essential oils from the peel of orange (Citrus auranticum L.) was studied and the results were compared with those of the conventional SD in terms of extraction time, extraction yield/efficiency, chemical composition, and quality of the essential oils. MSD was superior in terms of saving extraction time (140 min, compared to 7 h in SD) and extraction yield. Scanning electron microscopy (SEM) of orange peel undergone SD and MSD provided evidences as to a sudden rupture of essential oil glands with MSD. Gas chromatography–mass spectrometry analysis of the extracted essential oils indicated that the use of microwave irradiation did not adversely influence the composition of the essential oils. The result of this study demonstrate that MSD can be used as an alternative method to extract orange essential oil as growth promoter for fish

STUDY HERB ANATOMIC STRUCTURE OF THYMUS DIMORPHUS KLOK. ET SHOST

The article shows the results of an atomic structure of a herb of Thymus dimorphus. Mi-crodiagnostic signs were explored and determined during the study. Stem has a roundish-tetrahedral shape and a non-fascicular formation. Stomata are of the diacytic type. An availability and texture of the simple and glandular hairs are determined. So all along the Thymus dimorphus stem we have found bi- or threecellular thick-walled hairs with warty cuticle, more often they are cranked, the hairs of 5-9 cells with slightly warty surface, with grand content and glandular hairs on the bi- or threecellular stem with an elongated head and widened basal cell. There are simple unicellular hairs with slightly pointed apex and warty cuticle along the epidermis of a leaf, as well as bi- or threecellular cranked thick-walled hairs with fine-pointed apex with warty surface, the simple hairs of 4-8 cells with slightly widened cell walls and slightly warty cuticle. During the research of the flower's parts (calyx and corolla) a kind of pubescence by the different types of hairs and a shape of epidermal cells were determined. There are essential oil glands in the epidermis of the stem, leaf, calyx and corolla. The derived research results will allow identification of a specific belonging of thymes basing on diagnostic sings

Ohmic-assisted hydrodistillation of essential oils from Mentha piperita: a comparison with conventional hydrodistillation

Ohmic-assisted hydrodistillation (OAHD) is an advanced hydrodistillation (HD) technique utilizing ohmic heating process and could be considered as a novel method for the extraction of essential oils. Long extraction time is one of the major problems with traditional methods. OAHD of essential oils from the aerial parts of peppermint was studied and the results were compared with those of the conventional HD. The results showed that OAHD method had the extraction time of 19.71 min while this value was about 55.88 for HD. Scanning electron micrographs of mint leaves showed a sudden eruption of essential oil glands for OAHD samples. GC- MS analysis did not indicate any noticeable changes in the compounds of the essential oils obtained by OAHD in comparison with HD. The results introduced OAHD as a green technology.

Effect of applied voltage and frequency on extraction parameters and extracted essential oils from Mentha piperita by ohmic assisted hydrodistillation

Abstract Ohmic-assisted hydrodistillation (OAHD) is a new method proposed for extraction of essential oils in which ohmic heating technology is combined with distillation. In this study, different frequencies (25, 50 and 100 Hz) as well as high and low intensity OAHD (220 and 380 V) were applied on aerial parts of Mentha piperita L. and the results were compared with those of the conventional hydrodistillation (HD). The results showed that high and low intensity OAHD methods had the extraction times of 13.54 and 19.71 min, respectively, while this value was about 1 h for HD. Scanning electron micrographs of mint showed a sudden eruption of essential oil glands for all OAHD samples. GC–MS analysis did not indicate any noticeable changes in the compounds of all extracted essential oils. The results of this study showed that higher applied voltage can speed up OAHD and confirmed this emerging technology as a green technology (considering fossil fuels as the main source of electrical energy). Industrial relevance The quality and quantity of essential oils extracted from herbs and other raw materials are affected by the extraction method. In this research different frequencies (25, 50 and 100 Hz) and also high and low intensity OAHD (220 and 380 V, applicable in industries in many regions) of ohmic-assisted hydrodistillation (OAHD), as an innovative and emerging technology, were used and compared with traditional hydrodistillation in extraction of essential oils from the aerial parts of Mentha piperita L. (peppermint). All OAHD treatments were more economical and more environmentally friendly than hydrodistillation method. In addition, high intensity OAHD method not only can enhance the amount of extracted essential oil but also was the quickest method and consequently can be a valuable industrial alternative for extraction of essential oils.

Extraction of essential oils from Mentha piperita using advanced techniques: Microwave versus ohmic assisted hydrodistillation

Ohmic and microwave assisted hydrodistillation (OAHD and MAHD, respectively) are advanced hydrodistillation (HD) techniques utilizing ohmic and microwave heating processes for extraction of essential oils. OAHD and MAHD of essential oils from the aerial parts of peppermint were studied and the results were compared with those of the traditional HD. The results showed that OAHD and MAHD methods require less than half an hour for extraction process while HD require about 1h. Scanning electron microscopy of mint leaves undergone OAHD and MAHD provided evidences as to a sudden rupture of essential oil glands. GC–MS analysis did not indicate any noticeable changes in the compounds of the essential oils obtained by novel studied methods in comparison with HD. The results introduced OAHD as the greenest technique in terms of energy consumption. MAHD was superior in terms of rate of essential oils accumulation and also extraction duration parameter.

Biomorphological features of Lophanthus anisatus Adans introduced in conditions of ZhNAEU’s Botanical Garden

The paper establishes some special features of Lophanthus anisatus Adans growth, development and morphology which being introduced in the ZhNAEU’s Botanical Gardens. After seed propagation the plants are blossoming, they produce fruits and seeds of full value starting from the first year of life. A great number of trichomes and essential oil glands have been found on the stem epidermis, abaxial surface of the leaf, and calyx.

Sample preparation for single cell transcriptomics: essential oil glands in Citrus fruit peel as an example.

Many plant natural products are synthesized in specialized cells and tissues. To learn more about metabolism in these cells, they have to be studied in isolation. Here, we describe a protocol for the isolation of epithelial cells that surround secretory cavities in Citrus fruit peel. Cells isolated using laser microdissection are suitable for RNA isolation and downstream transcriptome analyses.

Comparison of ohmic-assisted hydrodistillation with traditional hydrodistillation for the extraction of essential oils from Thymus vulgaris L.

Abstract Ohmic-assisted hydrodistillation (OAHD) is an advanced hydrodistillation (HD) technique utilizing ohmic heating process and could be considered as a novel method for the extraction of essential oils. One of the major problems with traditional methods is long extraction time. OAHD of essential oils from the aerial parts of Thymus vulgaris L. (common thyme) was studied and the results were compared with those of the conventional HD. The results showed that OAHD method had the extraction time of 24.75 min while this value was about 1 h for HD. Scanning electron micrographs of thyme leaves showed a sudden eruption of essential oil glands and their surrounding area for OAHD samples. GC–MS analysis did not indicate any noticeable changes in the compounds of the essential oils obtained by OAHD in comparison with HD. Results of this study introduced OAHD as a green technology because of less energy required per ml of essential oil extraction. Industrial relevance The quality and quantity of essential oils extracted from herbs and other raw materials are affected by the extraction method. In this research ohmic-assisted hydrodistillation (OAHD) was used as an advanced and novel hydrodistillation (HD) technique and compared with traditional hydrodistillation in extraction of essential oils from the aerial parts of Thymus vulgaris L. (common thyme). OAHD method was quicker, more economical and environmentally friendly than hydrodistillation method. The results of this study introduced OAHD as a green technology.

Ohmic-assisted hydrodistillation of essential oils from Zataria multiflora Boiss (Shirazi thyme)

Ohmic-assisted hydrodistillation (OAHD) is a combination of ohmic heating and distillation, and could be considered as a novel method for the extraction of essential oils. Major problems with traditional methods are long extraction time and lower purity of the extract. In this study, OAHD was applied as an economic and green technology for the extraction of essential oils from Zataria multiflora Boiss. (Shirazi thyme) aerial parts and the results were compared to those obtained from hydrodistillation (HD) as a conventional method. The results showed that OAHD method had the extraction time of 32.21 ± 2.59 min while this value was about 57.21 ± 2.33 min for hydrodistillation (HD). Scanning electron micrographs of thyme leaves showed a sudden eruption of essential oil glands and their surrounding area for OAHD samples. GC–MS analysis indicated that both methods of OAHD and HD can extract the same compounds.

Floral scent in a whole‐plant context: moving beyond pollinator attraction

The natural world is awash with odours – blends of volatile organic compounds (VOCs) – whose chemical structures and composition convey information to organisms endowed with the sensory capacity to perceive them. Pheromones and other chemical signals provide specific information that facilitates kin recognition, mate acquisition, social interactions and defence across the tree of life (Meinwald & Eisner 2008). Even more general volatile cues, such as CO2, convey context-dependent information about habitat and host or food quality, illness and microbial decay (Guerenstein & Hildebrand 2007). The terrestrial fossil record teems with evidence of chemical communication and warfare, in the form of animal olfactory appendages (Strausfeld & Hildebrand 1999; Labandeira 2002) and plant essential oil glands (Fahn 2002; Krings, Taylor & Kellogg 2002). This evidence, combined with our knowledge of cycads, water lilies and other ‘living fossils’ (Thien, Azuma & Kawano 2000; Terry et al. 2007), attests to the antiquity of volatile communication between plants, their mutualists and antagonists.

Improved microwave steam distillation apparatus for isolation of essential oils: Comparison with conventional steam distillation

Steam distillation (SD) is routinely used by analysts for the isolation of essential oils from herbs, flowers and spices prior to gas chromatographic analysis. In this work, a new process design and operation for an improved microwave steam distillation (MSD) of essential oils from aromatic natural products was developed. To demonstrate its feasibility, MSD was compared with the conventional technique, SD, for the analysis of volatile compounds from dry lavender flowers ( Lavandula angustifolia Mill., Lamiaceae). Essential oils isolated by MSD were quantitatively (yield) and qualitatively (aromatic profile) similar to those obtained by SD, but MSD was better than SD in terms of rapidity (6 min versus 30 min for lavender flowers), thereby allowing substantial savings of costs in terms of time and energy. Lavender flowers treated by MSD and SD were observed by scanning electron microscopy. Micrographs provide evidence of more rapid opening of essential oil glands treated by MSD, in contrast to conventional SD.

Diversity of Essential Oil Glands of Spanish Sage (Salvia Lavandulifolia Vahl, Lamiaceae)

Salvia lavandulifolia (Spanish sage, Lamiaceae) is widely cultivated in the Mediterranean region and used for the flavor and food industry, perfumery and medicinal purposes. The essential oil, which is responsible for the specific flavor, is produced and stored in specialized epidermal oil glands. In S. lavandulifolia peltate essential oil glands occur on all aerial parts of the plant. The content of single oil glands from different positions on the plant (leaf, calyx, corolla and anther) were directly sampled using a solid-phase micro-extraction (SPME) fiber and analyzed by GC/FID and GC/MS in order to study the variability of the essential oil composition. It was found that the composition of terpenoids is quite variable within a plant. The leaves and calyces are characterized by the main compounds, 1,8-cineole, camphor and β-pinene, and by the sesquiterpenes α-humulene and β-caryophyllene. The corolla shows the highest proportion of borneol, but a low concentration of camphor. In the essential oil of the anthers the percentages of limonene, β-pinene and the diterpene manool are by far higher than in all other plant parts, whereas the proportions of camphor and the sesquiterpenes are considerably lower.

Identification and characterization of simple sequence repeat markers from a glandular Origanum vulgare expressed sequence tag

Oregano (Origanum vulgare) and marjoram (Origanum majorana) are two sensorial distinct spices within the genus Origanum (Lamiaceae). Simple sequence repeat (SSR) markers were developed from expressed sequence tags (ESTs) of essential oil glands of O. vulgare. Thirteen EST-SSR loci were evaluated using 20 individual plants of O. vulgare and 19 plants of Origanum majorana. The number of alleles per locus ranged from one to four. All loci developed from O. vulgare successfully cross-amplified in O. majorana.

Microwave‐assisted hydrodistillation of essential oil from Zataria multiflora Boiss

AbstractMicrowave‐assisted hydrodistillation (MAHD) has recently gained attention for the extraction of essential oils. A concern with the use of MAHD is the possibility of sample deterioration during the extended exposure to microwave irradiation. In this study, MAHD was applied as a new and green technology for the extraction of essential oil from Zataria multiflora Boiss. (Shirazi thyme) aerial parts. Superior results were obtained with the proposed method in terms of extraction time [1 h vs. 4 h in hydrodistillation (HD)] for an essential oil recovery of 3.66 and 3.44%, respectively. Images obtained from thyme leaves using scanning electron microscopy indicated a sudden eruption of essential oil glands undergoing MAHD. GC‐MS analysis of the essential oils did not indicate any new or missing compounds in the essential oil obtained by MAHD in comparison with that by HD. Therefore, a microwave oven can be safely used for the extraction of essential oil from Shirazi thyme.

Comparison of microwave-assisted hydrodistillation withthe traditional hydrodistillation method in the extractionof essential oils from Thymus vulgaris L.

Microwave-assisted hydrodistillation (MAHD) is an advanced hydrodistillation (HD) technique utilizing a microwave oven in the extraction process. MAHD of essential oils from the aerial parts (tops) of Thymus vulgaris L. (common thyme) was studied and the results were compared with those of the conventional HD in terms of extraction time, extraction yield/efficiency, chemical composition, quality of the essential oils and cost of the operation. MAHD was superior in terms of saving energy and extraction time (75min, compared to 4h in HD). Scanning electron microscopy (SEM) of thyme leaves undergone HD and MAHD provided evidences as to a sudden rupture of essential oil glands with MAHD. Gas chromatography–mass spectrometry analysis of the extracted essential oils indicated that the use of microwave irradiation did not adversely influence the composition of the essential oils. MAHD was found to be a green technology.

An improved microwave Clevenger apparatus for distillation of essential oils from orange peel

Microwave Clevenger or microwave accelerated distillation (MAD) is a combination of microwave heating and distillation, performed at atmospheric pressure without added any solvent or water. Isolation and concentration of volatile compounds are performed by a single stage. MAD extraction of orange essential oil was studied using fresh orange peel from Valencia late cultivar oranges as the raw material. MAD has been compared with a conventional technique, which used a Clevenger apparatus with hydro-distillation (HD). MAD and HD were compared in term of extraction time, yields, chemical composition and quality of the essential oil, efficiency and costs of the process. Extraction of essential oils from orange peels with MAD was better in terms of energy saving, extraction time (30 min versus 3 h), oxygenated fraction (11.7% versus 7.9%), product yield (0.42% versus 0.39%) and product quality. Orange peels treated by MAD and HD were observed by scanning electronic microscopy (SEM). Micrographs provide evidence of more rapid opening of essential oil glands treated by MAD, in contrast to conventional hydro-distillation.

Transpiration, essential oil glands, epicuticular wax and morphology ofThymus vulgarisare influenced by light intensity and water supply

SummaryPlants of two clonal selections of thyme (Thymus vulgaris) were grown under natural light and natural light supplemented by a PPF of 200 µmol m–2 s–1, provided by high pressure sodium lamps at 90%, 70% and 50% substrate water content in a greenhouse. Stomatal and cuticular transpiration, essential oil glands, epicuticular wax, and morphological traits were measured. Both stomatal transpiration and cuticular transpiration decreased under supplemental light and at low substrate water content. The time for which the stomata remained open or partially open was longer for plants developed under supplemental light at low substrate water content compared with variants grown under natural light and higher soil water content. The number of essential oil glands was significantly higher for plants grown under supplemental light (31 for ‘Laval 1’ and 27/2.27 µm2 for ‘Laval 2’) compared with natural light (23 for ‘Laval 1’ and 19/2.27 µm2 for ‘Laval 2’) grown plants. The lower the substrate water content, the h...