High Value Essential Oil Research Articles

Neuroinflammation and Acetylcholinesterase Inhibitory Potentials of a Spiroketal-Enol Ether Polyyne Isolated from Artemisia pallens Wall. ex DC.

Artemisia pallens Wall. ex DC (Asteraceae) is cultivated for the production of high-value essential oil from its aerial biomass. In this study, the chemical composition of the root (crop-residue) essential oil was investigated for the first time, using column-chromatography, GC-FID, GC-MS, LC-QTOF, and NMR techniques, which led to the identification of twenty constituents, with isolation of (E)-2-(2',4'-hexadiynylidene)-1,6-dioxaspiro [4.5]dec-3-ene (D6). The D6 was evaluated in vitro for neuroinflammation and acetylcholinesterase inhibitory potential. It showed inhibition of neuroinflammation in a concentration-dependent manner with significant inhibition of pro-inflammatory cytokines (TNF-α and IL-6) in LPS-stimulated BV2 microglial cells. D6 did not have any significant effect on the viability of the cells at the therapeutic concentrations. D6 also has shown acetylcholinesterase inhibitory potential (51.90±1.19 %) at the concentration of log 106 nM. The results showed that D6 has a potential role in the resolution of neuroinflammation, and its acetylcholinesterase inhibitory potential directs further investigation of its role in the management of Alzheimer's disease-related pathogenesis.

Chemical composition of the Kaempferia galanga L. essential oil and its in vitro and in vivo antioxidant activities.

Oxidative stress is closely related to the development of many diseases. Essential oils (EOs) show potent antioxidant activity from natural sources. Kaempferia galanga L. is an important medicine rich in high-value essential oil (KGEO). However, the antioxidant activity of KGEO remains to be fully studied. Chemical composition of KGEO was analyzed using gas chromatography-mass spectrometry (GC-MS). The antioxidant activity was determined using the DPPH, ABTS, hydroxyl radical scavenging assays and reducing power assay in vitro. A zebrafish model was used to evaluate the protective effect of KGEO against H2O2-induced oxidative stress damage in vivo. The major components of KGEO were found to be trans ethyl p-methoxycinnamate (32.01%), n-pentadecane (29.14%) and trans ethyl cinnamate (19.50%). In vitro pharmacological results showed that KGEO had good free radical scavenging capacity in DPPH, ABTS, and hydroxyl radical scavenging assays (IC50 values: 19.77 ± 1.28, 1.41 ± 0.01, and 3.09 ± 0.34 mg/mL, respectively) and weak reducing capacity in the reducing power assay (EC50 value: 389.38 ± 4.07 mg/mL). In vivo zebrafish experiments results indicated that the survival rate and heart rate increased, and ROS generation, cell death, and lipid peroxidation were attenuated after KGEO treatment. In addition, a decrease in malondialdehyde (MDA) levels and increases in superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px) activities were observed in the KGEO-treated groups. This study validated the in vitro and in vivo antioxidant activities of KGEO, which provides a theoretical basis for a profound study of KGEO and its application in the pharmaceutical, food and cosmetic industries.

An innovative ultrasonic-assisted extraction process for enhancing the patchoulol from Pogostemon cablin essential oil using hydrotropes

Pogostemon cablin (Patchouli) is an aromatic herb cultivated for its high-value essential oil. It is majorly used as a base oil in fragrance formulation due to its characteristics sesquiterpenoid alcohols. Patchoulol is an imperative and bioactive sesquiterpenoid in the patchouli essential oil, which is primarily isolated from the aerial part of the plant. The patchoulol was enriched in this essential oil by ultrasonic-assisted extraction techniques using different hydrotropes viz., sodium p-toluene sulphonate, resorcinol, sodium cumene sulphonate and sodium salicylate. The effect of various parameters such as extraction time (min), ultrasonic amplitude (%) and pulse interval (s) with 2 M concentration of hydrotropes was studied. Ultrasonic assisted-techniques has improved the percentage of patchoulol in patchouli essential oil. The highest composition of patchoulol i.e., 70.06 % was obtained for 5 min extraction time, 40 % ultrasonic amplitude, 30:30 s pulse interval for sodium salicylate at 2 M concentration.

Quantification of Genotypic and Chemotypic Diversity for Elite Clone Selection with High-quality Essential Oil Traits in Vetiver [Chrysopogon zizanioides (L.) Roberty

Vetiver (Chrysopogon zizanioides (L.) Roberty (Poaceae) is a perennial herbaceous grass. It is cultivated for the production of high-value essential oil, which imparts a robust and persistent woody odor escorted with different undertones such as earthy, grapefruit-like, flowery, smoked, ambery, etc. The study aims to determine the genotypic and chemotypic diversity in twenty-three genetic stocks of vetiver. The nature, proportion and degree of genetic diversity were evaluated using Mahalanobis D2-statistics on seven agro-economical quantitative traits. All the vetiver accessions were grouped into six clusters wherein, the inter-cluster distance was observed maximum in between I and III cluster pair (117.18) and minimum in II and IV cluster pair (64.98). Among seven economic characters, plant height (59.33 %) was found to be leading contributor toward genetic diversity, followed by essential oil yield (10.43 %). However, root length (2.77 %) showed the lowest contributing character towards genetic diversity. The genetic variability was also studied through percentage chemical constituents present in the essential oils. The result of the present study concluded to enhance the traits of auspicious OPSPs accessions, responsible for high oil yields with specific chemical constituents to meet the market demand of khus essential oil. The accession VS-20 and VS-23 were found to be highly divergent genotypes among all and could be chosen for further exploitation in the hybrid breeding program to develop superior cultivars of vetiver. The clones rich in specific constituent like khusinol (VS-9), khusimol (VS-11) and khusilal (VS-17) and high essential oil could also be selected for further exploitation.

Effect of Planting Date and Intercropping with Fenugreek (Trigonella foenum - graceum L.) on Yield and Essential Oil Content of Peppermint (Mentha piperita L.)

Peppermint (Mentha piperita L.) is one of the most important essential oil bearing plants. Satisfying the nutritional needs of a growing population whilst limiting environmental repercussions will require sustainable intensification of agriculture including intercropping systems. In order to investigate the effect of theses factors, a field experiment was conducted in a split plot arrangement based on randomized complete block design with three replications. Treatments were including planting dates (October 2, February 29 and April 29) as main plot and five replacement intercropping systems (fenugreek and peppermint sole crop and 1:1, 2:2 and 2:1 (two of fenugreek and one of peppermint) ratio assigned to sub plot. Yield, harvest index, phenol, essential oil and indices of advantage of intercropping were studied. Crops yield, essential oil and phenol content were influenced by planting date and intercropping systems. Results demonstrated that October 2 planting date showed the highest yield for both crops. A significant increase in essential oil content (% w/w) was found in February 29 and intercropping ratio 1:1. Even though biological yield of two crops was declined by intercropping, the advantage of intercropping system was higher than sole of fenugreek and peppermint. The highest land equivalent ratio and area time equivalent ratio were obtained from intercropping ratio of 1:1. The second harvest of peppermint had more yield and active substances than the first harvest. Therefore, it could be concluded that using of intercropping system and selection of best planting date are methods to optimize of the medicinal properties of crops. Intercropping ratio 1:1 and planting date October 2 will help to increase high value essential oil production and more benefit to peppermint/fenugreek growers and aroma industry.

De novo transcriptome analysis of rose-scented geranium provides insights into the metabolic specificity of terpene and tartaric acid biosynthesis

BackgroundRose-scented geranium (Pelargonium sp.) is a perennial herb that produces a high value essential oil of fragrant significance due to the characteristic compositional blend of rose-oxide and acyclic monoterpenoids in foliage. Recently, the plant has also been shown to produce tartaric acid in leaf tissues. Rose-scented geranium represents top-tier cash crop in terms of economic returns and significance of the plant and plant products. However, there has hardly been any study on its metabolism and functional genomics, nor any genomic expression dataset resource is available in public domain. Therefore, to begin the gains in molecular understanding of specialized metabolic pathways of the plant, de novo sequencing of rose-scented geranium leaf transcriptome, transcript assembly, annotation, expression profiling as well as their validation were carried out.ResultsDe novo transcriptome analysis resulted a total of 78,943 unique contigs (average length: 623 bp, and N50 length: 752 bp) from 15.44 million high quality raw reads. In silico functional annotation led to the identification of several putative genes representing terpene, ascorbic acid and tartaric acid biosynthetic pathways, hormone metabolism, and transcription factors. Additionally, a total of 6,040 simple sequence repeat (SSR) motifs were identified in 6.8% of the expressed transcripts. The highest frequency of SSR was of tri-nucleotides (50%). Further, transcriptome assembly was validated for randomly selected putative genes by standard PCR-based approach. In silico expression profile of assembled contigs were validated by real-time PCR analysis of selected transcripts.ConclusionBeing the first report on transcriptome analysis of rose-scented geranium the data sets and the leads and directions reflected in this investigation will serve as a foundation for pursuing and understanding molecular aspects of its biology, and specialized metabolic pathways, metabolic engineering, genetic diversity as well as molecular breeding.

Classification of essential oil composition in Rosa damascena Mill. genotypes using an electronic nose

One of the major problems in the industry of medicinal and aromatic plants (MAPs) is the absence of a quick, easy and inexpensive method for controlling the quality of these plants. Rosa damascena Mill., is an aromatic plant which is cultivated for its high-value essential oil in the world. In this study, essential oils were extracted from nine genotypes of Rosa, and their main components were identified by GC and GC–MS. Then, the samples from different genotypes were grouped in three classes (C1, C2, C3) based on their total percentage of the six most important constituents, which have a major role in the quality of essential oil (i.e., phenyl ethyl alcohol, trans rose oxide, citronellol, nerol, geraniol, geranial). An electronic nose (EN) system was designed based on metal oxide semiconductor (MOS) sensors, and trained to identify the categories to which samples of essential oils could be classified. The response patterns of the sensors were recorded and further analyzed by chemometrics methods. Based on the results, principal components analysis (PCA) and linear discrimination analysis (LDA) showed that 85% and 99% of sample variance could be explained by the first two principal components (PC1, PC2) and two linear discrimination axis (LD1, LD2), respectively. LDA was performed on sensor response variables by cross- validated dataset (5- fold) and the classification accuracy was 95%. Finally, an error-correcting output codes (ECOC) classifier as a multiclass model for support vector machines (SVM) was considered and the classification accuracy was increased to 99%. These results reveal that an EN can be used as a quick, easy, accurate and inexpensive system for the classification of essential oil composition in Rosa damascena Mill.

Foliar application of plant nutrients and kinetin modifies growth and essential oil profile in Rosa damascena under acidic conditions

Rosa damascena Mill. is cultivated for its high-value essential oil in different parts of the world. The flower yield and the composition of essential oil of R. damascena are strongly affected by a number of factors. Nevertheless, the interactive effects of foliar application of plant nutrients and kinetin and its time of application on yield and secondary metabolites profile of R. damascena under acidic conditions are still unclear. Thus, a field experiment comprising two different times of spray and five foliar spray treatments was conducted to test the hypothesis that flowering behavior and secondary metabolites profile can be modified through proper nutrient supply at right time. The foliar spray at flower bud appearance stage (S2) significantly (P ≤ 0.05) increased flower yield by about 10.0 % compared with the foliar application at axillary bud development stage (S1) during both years, regardless of plant nutrients. Among the foliar spray treatments, kinetin at 0.20 g L−1 registered about 23–39 % higher flower yield compared with the water spray control; however, remained statistically at par (P ≤ 0.05) with Ca(NO3)2 at 4.06 g L−1. Moreover, the percentage of major fragrance-bearing compounds of essential oil (β-citronellol + nerol, linalool, E-geraniol, and Z-citral) was marginally increased with Ca(NO3)2 compared with kinetin treatment. However, the percentages of major hydrocarbons, nonadecane and heneicosane, were noticeably increased when kinetin was applied at S1. Foliar application of kinetin and Ca(NO3)2 might be done to improve flower yield and essential oil content in R. damascena flowers.

Determining Costs and Profitability of Lavender Farms in Isparta Province of Turkey

Lavender is a perennial shrub cultivated primarily for its inflorescence which produces high value essential oil. In Turkey, a great deal of studies has been done regarding the calculation of input, cost and profit of many agricultural products. However; there are not sufficient studies for medical and aromatic plants. In this study, it was aimed to determine the production inputs, costs and profitability of lavender farms. As research field, Isparta Province, which constitutes significant portion of Turkey’s lavender production, was chosen. The material of this study consists of data obtained through face-to-face surveys with 38 farmers. The mean yield of farm was calculated as 1636.70 kg ha-1 while 1 kg lavender production cost was calculated as $0.95. The average selling price of farm for 1 kg of lavender was $1.57. The GPV from lavender farming was calculated as 2573.31$ ha-1. Gross profit and the net profit were calculated as $1695.08 and 1018.37 $ ha-1 respectively. Relative profit was found to be 1.65. Lavender production was an alternative and important source of income for producers in region. Therefore, governmental support to lavender can lead to improvements in profitability indicators.

Optimization of seed rate and seedling establishment technique for raising the nursery of French basil (Ocimum basilicum L.)

French basil (Ocimum basilicum L.) is known for its high value essential oil as well as medicinal properties. The field experiments spanning over two years (2013 and 2014) were conducted to optimize the seed rate and seedling establishment methods in French basil in nursery beds. The experiment comprised two sources of nutrition, five seed rates, two sowing techniques and four depth of sowing. The seed requirement for one hectare plantation was minimum (195.0gha−1) under 0.8g seed rate sown in vermicompost treated soil whereas the land requirement was minimum (59.4m2) under 4.0g seeds m−2 sown in vermicompost. Though the number of successfully raised seedlings was highest (909.0m−2) in seed broadcasting method, growth and establishment of seedlings was superior in line sowing at 0.5cm seeding depth. The seed and land requirement for raising the nursery of French basil was minimum (234.1gha−1and 60.6m2) under broadcasting of seeds at a 0.5cm depth. After taking an integrated view of the experimental results, the seedling of French basil in nursery bed is recommended to be grown by using 0.8gm−2 seed after application of vermicompost @ 1kgm−2 in nursery bed at 0.5cm depth through line sowing technique.

Performance of rose scented geranium (Pelargonium graveolens) in heavy metal polluted soil vis-à-vis phytoaccumulation of metals

ABSTRACTAn investigation was carried out to evaluate the effect of heavy metal toxicity on growth, herb, oil yield and quality and metal accumulation in rose scented geranium (Pelargonium graveolens) grown in heavy metal enriched soils. Four heavy metals (Cd, Ni, Cr, and Pb) each at two levels (10 and 20 mg kg–1 soil) were tested on geranium. Results indicated that Cr concentration in soil at 20 mg kg–1 reduced leaves, stem and root yield by 70, 83, and 45%, respectively, over control. Root growth was significantly affected in Cr stressed soil. Nickel, Cr, and Cd concentration and accumulation in plant increased with higher application of these metals. Chromium, nickel and cadmium uptake was observed to be higher in leaves than in stem and roots. Essential oil constituents were generally not significantly affected by heavy metals except Pb at 10 and 20 ppm, which significantly increased the content of citronellol and Ni at 20 ppm increased the content of geraniol. Looking in to the higher accumulation of toxic metals by geranium and the minimal impact of heavy metals on quality of essential oil, geranium can be commercially cultivated in heavy metal polluted soil for production of high value essential oil.

Agro morphological, chemical and genetic variability studies for yield assessment in clary sage (Salvia sclarea L.)

Clary sage (Salvia sclarea L.) is an industrial crop grown for its high value essential oil, widely used in perfumery and cosmetic industries. In the present work, agromorphological characteristics, essential oil content and composition and randomly amplified polymorphic DNA (RAPD) markers were studied to estimate the relationships among 11 clary sage accessions, with a known variety CIM-Chandni grown in northern Indian plains. The clary sage accessions were distinguished on the basis of agro-morphological traits and essential oil constituents. As a consequence, these were grouped into dwarf, medium and tall; early and late maturing; low, medium and high yielding. Maximum genotypic coefficient of variation was recorded for spike weight plant−1 followed by spike length and plant height. In general, the genotypic correlation was higher than phenotypic. Significant positive genotypic correlation was recorded for plant height with spike length, days to flowering with days to maturity and spike weight plant−1, spike length with oil content. A high direct positive effect on oil content was because of spike length. The variety CIM-Chandni showed genetic similarity with all its progenies except SS1. Accession SS1 selected as a distinct and best performing genotype based on agro-morphic, quantitative, qualitative traits and RAPD profiling.

Adsorptive recovery of high value essential oil from kewda (Pandanus fascicularis Lam) distillation condensate

AbstractKewda (Pandanus fascicularis Lam) essential oil was enriched with phenylethyl methyl ether (65–77%), terpinen‐4‐ol (13–18%) and α‐terpineol (1–3%), which were definitely soluble in distillation condensate. The solubility of phenylethyl methyl ether, terpinen‐4‐ol and α‐terpineol in water were more than 1000 ppm. Adsorption performance of single‐solutes and multi‐solutes over Amberlite‐resins and Indion‐resins were elucidated. XAD‐4 and Indion 1014 MN‐2 were most suitable because of their higher loading capacities of 2.2–3.2 mmol g−1 and 2.3–3.6 mmol g−1, respectively. Temkin adsorption isotherm was best fitted to the experimental results. Adsorption was followed Pseudo‐second order, Ritche's‐second order and Elovich's equation to validate the kinetics of chemisorption. Column breakthrough results revealed that the water soluble essential oil was recovered from the distillation condensate through a resin bed. Then the adsorbed solutes were desorbed from the resins with elution in ethanol to achieve complete recovery of high value essential oil from the distillation condensate. © 2015 Curtin University of Technology and John Wiley & Sons, Ltd.

Growth, yield and economics of vetiver (Vetiveria zizanioides L. Nash) under intercropping system

Vetiver (Vetiveria zizanioides L.) is a high value essential oil crop, used as fixative in perfumery and cosmetic industries. Besides, the crop is also used to check soil erosion, water conservation, and reclamation of salt affected soils. Being vetiver a wider spaced crop with a long initial lag phase, thus the only option to sustain its productivity is intercropping. In a field experiment conducted during July, 2010–February, 2012 and July, 2012–February, 2014 at Lucknow, 13 cropping systems: sole crop of each of vetiver, sweet basil–radish–Tagetes minuta, black gram–clarysage, kalmegh–garlic, okra–radish–geranium, pigeon pea–menthol mint, maize–radish–onion and intercropping of above cropping sequences with vetiver were evaluated in randomized block design with three replications. Intercropping of sweet basil–radish–T. minuta with vetiver during rainy and winter seasons though reduced vetiver oil yield by 16.7% but was highly productive in terms of land equivalent ratio (1.54), land use efficiency (130%) and relative net return (1.35) and a net return of US$ 4801.7ha−1 followed by intercropping of maize–radish–onion with vetiver. The system also gave about 35% more profit over the sole cropping of vetiver.

Production potential, nitrogen use efficiency and economics of clarysage (Salvia sclarea L.) varieties as influenced by nitrogen levels under different locations

Clarysage (Salvia sclarea L.) is known for its high value essential oil, widely used in perfumery as a source of fragrance with refreshing and long lasting note. Ten treatment combinations consisting of two clarysage varieties (Local and CIM-Chandni) and five nitrogen levels (0, 40, 80, 120 and 160kgNha−1) were evaluated in factorial randomized block design with three replications at three locations; Lucknow (Sub-tropical plain), Pantnagar (foot hills of Himalayas) and Purara (western Himalayas). Crop matured 9 and 27 days earlier at Lucknow as compared to Pantnagar and Purara, respectively. Flower spike and oil yields were highest at Pantnagar as compared to other locations. In spite of lowest yields at Purara plant synthesized significantly more oil due to lower temperature, longer life span and higher spikes:leaf+stem ratio. Linalyl acetate content in oil was highest at Lucknow followed by Pantnagar and Purara. Variety CIM-Chandni had significantly higher flower spikes, spikes:leaf+stem ratio, oil content and produced higher oil of better quality. Optimum doses of nitrogen were worked out to be 107.6 and 116.5kgha−1 at Lucknow, 117.2 and 105.2kgha−1 at Pantnagar, 159.8 and 132.6kgha−1 for local and CIM-Chandni, respectively.

Changes in growth, yield, photosynthetic characteristics, enzyme activities and essential oil production of fennel (Foeniculum vulgare Mill.) under growth regulator treatments

Fennel (Foeniculum vulgare Mill.) belongs to the Apiaceae family. It is a high value medicinal and essential oil bearing crop used in pharmaceutical, food and cosmetic industries. Keeping the medicinal as well as economic importance of this herb in mind, a pot experiment was carried out under the net house conditions of the Botanical Garden, Fort, AMU, Aligarh. The experiment was conducted using a randomized block design with four replications. This study was conducted to assess the effects of triacontanol (TRIA) alone and in combination with gibberellic acid (GA3) on growth characteristics, photosynthetic parameters, some other physiological and biochemical attributes, composition and yield of essential oil of fennel. At 30 days after sowing, the plants were sprayed with either TRIA or with different combination of TRIA and GA3. Among the treatments, foliar spray of 10−6 TRIA + 10−6 GA3 significantly promoted the values for most of the growth, physiological and biochemical attributes as well as for essential oil composition and yield attributes. It was concluded that a combined spray of TRIA and GA3 (10−6 TRIA + 10−6 GA3) might be highly effective for increased productivity and essential oil composition of fennel.

Biomass yield, essential oil yield and quality of geranium (Pelargonium graveolens L. Her.) as influenced by intercropping with garlic (Allium sativum L.) under subtropical and temperate climate of India

Rose scented geranium (Pelargonium graveolens L. Her.), a perennial herb is grown for the production of high value essential oil that finds extensive use in flavouring and fragrance industries. Geranium is propagated through rooted stem cuttings or fresh terminal stem cuttings .at a row spacing of 60cm. Its initial growth rate is very slow, to utilize the uncovered inter row space and other applied and natural growth resources and to enhance the productivity, attempts were made to work out the optimum row ratio of garlic (Allium sativum L.) intercropped with geranium to get bonus yield of garlic without affecting oil yield of geranium. Field experiments were conducted for two growing seasons (October–June) of 2007–2008 and 2008–2009 under subtropical climate at Lucknow and temperate climate at Purara. Intercropping of two rows of garlic between the two rows of geranium planted at 60cm row spacing and 30cm plant spacing produced 1860 and 2400kgha−1bonus yield of garlic bulb without any significant reduction in geranium essential oil yield. It resulted in 59 and 60.5% increase in land use efficiency and 29.3 and 81.3% increase in net return over sole geranium at Lucknow and Purara, respectively.

Improving production potential and resources use efficiency of peppermint (Mentha piperita L.) intercropped with geranium (Pelargonium graveolens L. Herit ex Ait) under different plant density

Peppermint ((Mentha piperita L.), family, lamiaceae) is vegetatively propagated (through runners or stolon and rhizomes) high demand aromatic/medicinal crop. Geranium (Pelargonium graveolens L. Herit ex Ait, family, Geraniaceae) is also vegetatively propagated (through rooted stem cutting), high value aromatic crop. Essential oil is extensively used in fragrance, aromatherapy, flavor, and pharmaceutical industries. A field experiment was conducted at CIMAP, Research Centre Farm, Bageshwar, Uttarakhand, India during 2006–08 (two cropping seasons), to increase the production potential, resource use efficiency and monetary advantages of peppermint intercropping with geranium in temperate climate. The intercropping systems evaluated under different plant density (75cm×45cm, 90cm×45cm and 120cm×45cm) on biomass yield, essential oil content, yields and quality, resource use efficiency and monetary advantages of the intercropping system. Yield and quality attributes of peppermint was significantly influenced by plant density and intercrop. Under this intercropping system plant density 90cm×45cm was found maximum yield advantages and resource utilization efficiency over 120cm×45cm and 75cm×45cm, while monocrop peppermint at plant density 75cm×45cm was superior and produced 77.3% and 82.0% higher biomass and oil yield, respectively compared to wider spacing (120cm×45cm). The land equivalent ratio (LER) area time equivalent ratio (ATER), land use efficiency (LUE %) and monetary retunes were higher in 90cm×45cm spacing followed by 75cm×45cm over monocrop. The quality of essential oils of both the crops was good and acceptable for market. This intercropping system will help to increase high value essential oil production and more benefit to peppermint/geranium growers and aroma industry in temperate region.

Depolymerized carrageenan ameliorates growth, physiological attributes, essential oil yield and active constituents of Foeniculum vulgare Mill

Irradiated carrageenan (IC) elicits an array of plant defense responses and biological activities in plants. An experiment was carried out in the naturally illuminated conditions of net house in order to assess the effects of foliar spray of IC on agricultural performance of fennel (Foeniculum vulgare Mill.), which is a high-value essential oil bearing medicinal crop used in pharmaceutical, food and cosmetic industries. There were applied four IC concentrations (40, 60, 80 and 100mgL−1) as foliar sprays. Application of IC significantly improved the growth attributes, physiological and biochemical parameters, essential oil yield and the contents of main components of essential oil of fennel. IC applied at 80mgL−1 enhanced these parameters maximally. Unirradiated carrageenan and deionized water had no effect on the attributes studied. Moreover, GLC analysis revealed a significant increase in the components of essential oil, viz. fenchone (4.48–7.82%) and anethole (78.38–86.08%) compared to the control.

A quality control method for geranium oil based on vibrational spectroscopy and chemometric data analysis

Rose-scented geranium, a commercially important cultivar originating from Pelargonium graveolens L’Her. ex Ait., is a high value essential oil extensively used in flavour and fragrance formulations. The oil is variable in composition with ‘Bourbon geranium’ (from Reunion Island) regarded as the highest quality geranium oil. Quality assessment of geranium oil involves profiling seven major volatile constituents (geraniol, citronellol, geranyl formate, citronellyl formate, linalool, isomenthone and guaia-6,9-diene) using gas chromatography (GC). The aim of this study was to explore the feasibility of vibrational spectroscopy in tandem with chemometric methods as a rapid and low-cost alternative quality control method. Geranium oil samples ( n = 70) were obtained from different suppliers representing cultivation sites in South Africa, Egypt, India, Reunion Island, China and Madagascar. Reference analysis was performed using gas chromatography coupled to mass spectrometry (GC–MS). The mid-infrared (MIR) and near-infrared (NIR) spectra of the oils were recorded with a total of 32 scans accumulated for each sample. Partial least squares (PLS) multivariate calibration models were developed. The calibration models obtained for both MIR and NIR data produced good correlation coefficients ( R 2 > 0.90) between the predicted and reference values for all seven marker molecules. Generally, the error parameters (RMSEE and RMSEP) after external validation were low (<1.0%) for all compounds guaranteeing reliable predictions. The results show convincingly the potential of both MIRS and NIRS as alternative methods that can be used in quality assessment of geranium oil providing sufficiently accurate results.