Recovery Of Essential Oil Research Articles

Recovery of essential oils, polyphenols, fermentable sugars, and pectin from orange residues: Evaluation of extraction methodologies and characterization of value-added bioactive compounds

Recovery of essential oils, polyphenols, fermentable sugars, and pectin from orange residues: Evaluation of extraction methodologies and characterization of value-added bioactive compounds

A simulation‐guided tri‐spiral condenser design for enhancing lemongrass essential oil recovery

AbstractWe present a groundbreaking achievement in essential oil extraction, showcasing the development of a highly efficient tri‐spiral condenser for use in microwave‐assisted extraction (MAE) setups. This innovative condenser is specifically designed to swiftly cool vapors, optimizing oil yield during the MAE process. Our investigations demonstrate a notable improvement in oil purity, attributed to the expedited condensation facilitated by the tri‐spiral design. Traditional heat exchangers, like the Liebig condenser, fall short in efficiently handling the high vapor production rates of MAE. In response to this challenge, our tri‐spiral condenser design enhances condensation speed, resulting in a remarkable 12.2% increase in oil yield compared with the Liebig condenser (2.1% with tri‐spiral vs. 1.87% with Liebig), as validated by Gas Chromatography–Mass Spectrometry. Beyond elevating oil purity, our design holds promise for diverse applications requiring rapid cooling. This work not only advances laboratory practices but also contributes to the broader societal need for efficient and sustainable methods in the essential oil extraction industry.Practical applicationsThe innovative tri‐spiral condenser design, as elucidated in this article, presents significant practical applications, especially in the realm of lemongrass essential oil recovery. This breakthrough technology holds promise for the fragrance and cosmetics industries, where lemongrass essential oil is a valuable ingredient. The novel condenser design enhances extraction efficiency, leading to a higher concentration of essential oil with improved aromatic compounds. Cosmetic manufacturers can benefit from a more potent and fragrant lemongrass oil for skincare and aromatherapy products. Additionally, the pharmaceutical sector could leverage this advancement for developing therapeutic products harnessing the medicinal properties of lemongrass. By optimizing essential oil recovery, the tri‐spiral condenser design not only caters to the needs of the fragrance, cosmetic, and pharmaceutical industries, but also aligns with a broader trend towards sustainable and efficient manufacturing practices, ensuring the accessibility of high‐quality lemongrass essential oil for diverse applications.

Studies on the effect of different shade drying periods of lemongrass (Cymbopogon flexuosus Steud.) on recovery of essential oil

Studies on the effect of different shade drying periods of lemongrass (Cymbopogon flexuosus Steud.) on recovery of essential oil

Influence of Enzymatic Pretreatment and Optimization on Hydro Distillation Recovery of Essential Oils from Allium cepa

Influence of Enzymatic Pretreatment and Optimization on Hydro Distillation Recovery of Essential Oils from Allium cepa

Differential Expression of Oman’s Wild Lavender, Lavandula subnuda for Chemical Composition towards Medicinal and Aromatic Application

Plants have been used directly or indirectly as medicines for over 5000 years as a source of antibiotics, antineoplastics, analgesics, and cardio-protective, among others. Approximately 70–90% of the population in developing countries continue to use ancient medicines based on plant extracts for treatment. Recently, the isolation and identification of biologically active compounds and molecules from nature have led to the discovery of new therapeutics, prompting the improvement of the health and pharmaceutical sectors. Phytochemicals revolve around the pharmaceutical industry's research and development (R&D) sector as a source of new molecules leading to the development of new novel drugs. Given the above, the present investigation addresses the differential nature of wild lavender (Lavandula subnuda Benth) plants of diverse locations in Oman with respect to their chemical composition of the essential oil in addition to morphological characters and chlorophyll contents of leaves to explore the possibility of isolating its prime chemical compounds on a commercial scale in perfumery industry. There are no previous studies so far who have reported on essential oil recovery and chemical composition exclusively in respect of Lavandula subnuda. Composite samples of ten randomly selected plants were collected from wadi habitats of four diversified locations. Edaphic features of managed sites were recorded, and their soil chemical contents were determined following instructions using S1 Titan/Tracer 5/CTX equipment of Bruker developed based on energy dispersive X-ray fluorescence (EDXRF). Morphological traits were measured using a ruler, and chlorophyll contents were recorded using the atLEAF CHL Plus chlorophyll meter as atLEAF values. The essential oil was extracted using ETHO X's advanced microwave extraction system and analyzed for chemical compounds using GC-MS analysis on Shimadzu GC-2010 Plus gas chromatograph. The experimental data were analyzed statistically, wherever required, by applying basic statistics of the EXCEL -16 version. The results indicated that in general, the Lavandula subnuda plants of locations of high altitudes had higher expressivity in all the morphological traits and chlorophyll contents than those of low altitudes. The essential oil recovery, however, was found to be higher from the plant samples of lower altitudes (0.70 to 0.79% (w/w)) than from those of higher mountains/ altitudes (0.15 to 0.18% (w/w)). The pattern of values of commonly occurring chemical contents of essential oils was different. Each essential oil's top ten chemical compounds contributed about 80% of the total in four locations. Of the ten top chemical compounds, eight compounds, namely D-Germacrene (42.67%) from Wadi Al-Khod, Estragole (32%) and Linalool (23.89%) from Wadi Halban), trans-Borneol (23.46%) and 4-Terpineol (18.73%) from Wadi Najd Al-Waqba and Kessane (18.60%), beta-cis-Caryophyllene (13.68%) and beta-Elemene (10.618%) from Wadi Al-Hayul, were found highest in quantity and had huge potential for further application. It is concluded that there exists a higher possibility of adapting Good Agriculture Practice (GAP) to produce the highest herbage yield of vegetative parts of Lavandula subnuda plants based on morphological features under wild conditions to extract these compounds on a commercial scale in both the pharmaceutical and perfumery industries.
 Keywords: Morphology, Chlorophyll, Chemical compounds, Differential Expression, Lavandula subnuda,, Lamiaceae

Recovery of essential oils from the withered flowers of Magnolia soulangeana Soul.-Bod. by microwave-assisted hydrodistillation with uniform heating and its new application in the hypolipidemic field

This study innovatively designed a microwave-assisted hydrodistillation method with uniform heating to extract the essential oil from the withered flowers of Magnolia soulangeana Soul.-Bod., in which the addition of the rotating unit is applied to improve the uneven heating of plant materials caused by the fixation of the flask and the energy point in the microwave system, and the soaking pretreatment unit is used to fully swell the plant cells and accelerate the overflow of essential oils. Meanwhile, the significance of the independent variables that may affect the yield of essential oil and the optimal conditions were screened and optimized by means of response surface methodology, and the results showed that the introduction of the rotation unit and soaking pretreatment unit increased the yield of essential oil by 16.67% and 20%, respectively, which highly promoted the increase of the yield and extraction rate of essential oil. Moreover, the samples obtained by this new method are rich in terpene compounds, such as eucalyptol, δ-cadinene, α-muurolene, and germacrene D, which is consistent with the results of traditional hydrodistillation, and also further illustrates the safety of this method. And the hypolipidemic activity of these compounds was also verified, and the main compound in the essential oil that exerts the hypolipidemic activity may be δ-cadinene, and its possible target for reducing total cholesterol content is Niemann-Pick C1-like 1. In addition, this study also shows that this new method shows lower energy consumption and environmental pressure and is very promising to replace the existing method for the large-scale preparation of essential oils.

Evaluation of Morphological Characteristics, Yield Potential, and Essential Oil Composition of Ocimum sanctum Genotypes for Crop Improvement

Ocimum sanctum, also known as Holy Basil, is an aromatic herb with a long history of use in traditional medicine. It is native to tropical and subtropical regions of Asia and is now cultivated worldwide. Plants have erect, much-branched sub-shrub with simple opposite green or purple leaves that are strongly scented and hairy stems and leaves has a strong, characteristic aroma that occurs mainly because of the volatile oils present.
 In this experiment, 30 genotypes of Ocimum sanctum were evaluated for morphological, yield and quality traits. At nursery stage, germination percentage, seedling shoot length and seedling root lengths were recorded. Among the accessions. OS-22 exhibited the highest germination percentages (82%), Seedling shoot and root length were highest in Os-18 and OS 21 (35 cm and 11 cm) respectively. In the main field, the accessions were characterized for qualitative traits viz growth habit, leaf colour and stem colour. The accessions were grouped into two, based on growth habit. Based on stem and leaf colour the accessions were grouped into five and four groups respectively. In case of quantitative traits, plant height achieved maximum in the accession OS 22 (88cm) followed by OS 17(75cm). The accessions OS-15 and OS-22 exhibited more extensive plants spread, while OS-21 and OS-13 had higher number of primary branches. Accessions OS-20 and O S-23 recorded more number of leaves (409 and 422) and the accessions O S-22 and OS-11 recorded highest fresh leaf weight (370.2 g & 301.67 g). The essential oil recovery and oil yield was highest in the accession OS 20 (green type) followed by OS 22 (purple type). Characterization of oil in GCMS revealed that the key component was eugenol, which showed highest content in accession Os-20 (46 %). This study can be used for further crop improvement studies and breeding programs.

Integration of organic and inorganic inputs impact on essential oil composition and morphological characters of Monarda citriodora Cerv. ex Lag grown in Jammu region of India

Monarda citriodora is an important annual aromatic plant well known for its essential oil and herbal value. Considering its economic importance, an experiment was carried out during year 2022 and 2023 at CSIR-IIIM Jammu to determine the influence of inorganic fertilizers and poultry manure on its vegetative growth, productivity, and essential oil composition. Eight different combinations of poultry manure with inorganic fertilizers laid in RBD were compared with control. The essential oil was extracted and its composition was determined using GC-MS and GC-FID by comparing with standard compounds. Results revealed that among treated plants the combination of poultry manure with chemical fertilizers behaved at par with plants treated with chemical fertilizers only. Maximum plant height at earlier stages was reported for plants treated with chemical fertilizers, but at later stages, plants receiving poultry manure attained maximum height (69.73 cm). Similar trend was followed for number of branches where plants receiving poultry manure and chemical fertilizers grow maximum number of branches (18.33). Maximum plant biomass (136.33g/per plant) was reported for plants receiving poultry manure in combination with chemical fertilizers. The treatment having poultry manure resulted in the highest organic carbon in soils 0.66%. Maximum essential oil recovery (2.11 ml/200g) was observed in T7 (MOP +Urea). The major constituents reported in essential oil were thymol (47.8-78.02%), γ-terpinene (6.30-19.16%) and p-cymene (4.54-17.04%). The study reveals, for increasing crop productivity and quality along with maintaining soil fertility, the mixed application of organic and inorganic fertilizers should be followed.

Exploiting the Integrated Valorization of Eucalyptus globulus Leaves: Chemical Composition and Biological Potential of the Lipophilic Fraction before and after Hydrodistillation.

E. globulus leaves have been mainly exploited for essential oil recovery or for energy generation in industrial pulp mills, neglecting the abundance of valuable families of extractives, namely, triterpenic acids, that might open new ways for the integrated valorization of this biomass. Therefore, this study highlights the lipophilic characterization of E. globulus leaves before and after hydrodistillation, aiming at the integrated valorization of both essential oils and triterpenic acids. The lipophilic composition of E. globulus leaves after hydrodistillation is reported for the first time. Extracts were obtained by dichloromethane Soxhlet extraction and analyzed by gas chromatography-mass spectrometry. In addition, their cytotoxicity on different cell lines representative of the innate immune system, skin, liver, and intestine were evaluated. Triterpenic acids, such as betulonic, oleanolic, betulinic and ursolic acids, were found to be the main components of these lipophilic extracts, ranging from 30.63-37.14 g kg-1 of dry weight (dw), and representing 87.7-89.0% w/w of the total content of the identified compounds. In particular, ursolic acid was the major constituent of all extracts, representing 46.8-50.7% w/w of the total content of the identified compounds. Other constituents, such as fatty acids, long-chain aliphatic alcohols and β-sitosterol were also found in smaller amounts in the studied extracts. This study also demonstrates that the hydrodistillation process does not affect the recovery of compounds of greatest interest, namely, triterpenic acids. Therefore, the results establish that this biomass residue can be considered as a promising source of value-added bioactive compounds, opening new strategies for upgrading pulp industry residues within an integrated biorefinery context.

Bioactive Profile of Distilled Solid By-Products of Rosemary, Greek Sage and Spearmint as Affected by Distillation Methods.

By-products of essential oils (EOs) in the industry represent an exploitable material for natural and safe antioxidant production. One representative group of such by-products is distilled solid residues, whose composition is properly modulated by the distillation method applied for the recovery of EOs. Recently, in terms of Green Chemistry principles, conventional extraction and distillation processes are considered outdated and tend to be replaced by more environmentally friendly ones. In the present study, microwave-assisted hydro-distillation (MAHD) was employed as a novel and green method for the recovery of EOs from three aromatic plants (rosemary, Greek sage and spearmint). The method was compared to conventional ones, hydro-distillation (HD) and steam-distillation (SD), in terms of phytochemical composition of distilled solid residues, which was estimated by spectrophotometric and chromatographic methods. Total phenolic content (TPC), total flavonoid content (TFC) and antioxidant activity (ABTS, DPPH and FRAP) results highlighted the distilled solid residues as good sources of antioxidants. Moreover, higher antioxidant activity was achieved for MAHD extracts of solid residues in comparison to HD and SD extracts. A metabolomics approach was carried out on the methanolic extracts of solid residues obtained by different distillation methods using LC-MS analysis followed by multivariate data analysis. A total of 29 specialized metabolites were detected, and 26 of them were identified and quantified, presenting a similar phenolic profile among different treatments, whereas differences were observed among different species. Rosmarinic acid was the most abundant phenolic compound in all extracts, being higher in MAHD extracts. In rosemary and Greek sage extracts, carnosol and carnosic acid were quantified in significant amounts, while trimers and tetramers of caffeic acid (salvianolic acids isomers) were identified and quantified in spearmint extracts, being higher in MAHD extracts. The obtained results pointed out that MAHD extracts of distilled solid by-products could be a good source of bioactives with potential application in the food, pharmaceutical and cosmetic industries, contributing to the circular economy.

The Influence of Cryogrinding on Essential Oil, Phenolic Compounds and Pigments Extraction from Myrtle (Myrtus communis L.) Leaves

The aim of this study was to investigate the influence of cryogrinding pretreatment on the recovery of essential oil, phenolics and pigments from myrtle leaves. The duration of cryogrinding (3, 6 and 9 min) in combination with the duration of hydrodistillation (30, 60 and 90 min) for the isolation of essential oils and the duration of hydroethanolic extraction (5, 10 and 15 min) for the isolation of phenols and pigments were studied as independent factors in a full factorial design. The major volatile components detected in myrtle leaf essential oil were myrtenyl acetate, 1,8-cineole, α-pinene and linalool. The most abundant phenols detected were myricetin derivatives (myricetin 3-O-galactoside and myricetin 3-O-rhamnoside), galloylquinic acid, myricetin and digalloylquinic acid, while the major pigments were chlorophyll b, pheophytin a and lutein. A 3 min cryogrinding pretreatment significantly increased the yield and concentrations of essential oil volatile compounds and reduced the distillation time to 30 min. A 9 min cryogrinding pretreatment and 15 min extraction resulted in at least 40% higher concentrations of phenolic compounds and pigments in the extracts when compared to the untreated control. According to the results obtained, cryogrinding can significantly increase the yield of myrtle EO and extracts and also modulate their composition.

Modeling and optimization of non-isothermal convective drying process of Lavandula × allardii

Non-isothermal convective drying schemes were examined for Lavandula × allardii leaves and inflorescences. Drying process parameters were optimized using response surface methodology (RSM) to ensure the peak operational performance. The effects of temperature increase rate (2–4 °C/h) and the airflow velocity (1–3 m/s) on the essential oil yield, drying duration and consumption, were investigated. A face-centered central composite design was deployed and the experimental data was adapted to the most suitable polynomial models, as determined by the regression analysis. Analysis of variance was applied to assess the effects of the process variables, their interactions and the statistical significance of the examined models. Both factors of temperature increase rate and airflow velocity had a significant impact on the drying duration. Airflow velocity had a greater effect on leaves’ essential oil yield and inflorescences’ process energy consumption, whereas the rates of temperature increase had a greater influence on the inflorescences’ essential oil yield and leaves’ energy consumption. The minimum drying duration and energy consumption were obtained for the maximum temperature increasing rate at 3 and 1 m/s airflow velocities respectively; and the highest essential oil yield was obtained for the least rate of temperature increase and airflow velocity for both leaves and inflorescences. Numerical optimization was performed for minimizing drying duration and energy consumption by maximizing the essential oil yield. The rate of temperature increases of 4 °C/h and the airflow velocity of 1 m/s, were proposed as the optimum non-isothermal drying conditions for both leaves and inflorescences of Lavandula × allardii. Predicted values of essential oil content have been 1.387/3.05 mL/g, 4.21/4.18 h drying time and 0.809/0.732 kWh energy consumption at the optimum operation point for leaves and inflorescences, respectively. The resulted optimized non-stationary temperature scheme considerably improved the drying kinetics and the process consumption by achieving a similar essential oil recovery with the standard low-temperature convective drying. The present study aimed to eliminate the preexisting gap of the optimum selection of the process parameters for the particular type of the examined non-isothermal drying schemes. Previous findings could be utilized for designing dryers and drying schedules aiming to retain the qualitative attributes, by reducing the cost and duration of the drying operations.

Adsorption of Polar Species at Crude Oil-Water Interfaces: the Chemoelastic Behavior.

We investigate the formation and properties of crude oil/water interfacial films. The time evolution of interfacial tension suggests the presence of short and long timescale processes reflecting the competition between different populations of surface-active molecules. We measure both the time-dependent shear and extensional interfacial rheology moduli. Late-time interface rheology is dominated by elasticity, which results in visible wrinkles on the crude oil drop surface upon interface disturbance. We also find that the chemical composition of the interfacial films is affected by the composition of the aqueous phase that it has contacted. For example, sulfate ions promote films enriched with carboxylic groups and condensed aromatics. Finally, we perform solution exchange experiments and monitor the late-time film composition upon the exchange. We detect the film composition change upon replacing chloride solutions with sulfate-enriched ones. To the best of our knowledge, we are the first to report the composition alteration of aged crude oil films. This finding might foreshadow an essential crude oil recovery mechanism.

Chemical Diversity of Essential Oil of Valeriana jatamansi from Different Altitudes of Himalaya and Distillation Methods.

Valeriana jatamansi is an important temperate herb that is used in the pharmaceutical and essential oil industries. In India, this species is now on the verge of extinction due to the over-exploitation of its rhizomes from its natural habitat. It is hypothesized that the variations in bioactive compounds in its essential oil are very high among the wild populations as well as cultivated sources. Thus, this study was conducted to evaluate the chemical profiling of essential oil of four wild populations (Rupena, Kugti, Garola, and Khani) and two cultivated sources (CSIR-IHBT, Salooni), which were distilled at three consecutive days. The variation in oil concentration in roots/rhizomes was found significant (p ≤ 0.05), and the maximum value (0.35%) was registered with the population collected from Kugti and Khani. In essential oil, irrespective of population and distillation day, patchouli alcohol was the major compound, which ranged from 19 to 63.1%. The maximum value (63.1%) was recorded with the essential oil obtained from Garola’s population and distilled on the first day. The percentage of seychellene was abruptly increased with subsequent days of extraction in all the populations. The multivariate analysis revealed that the essential oil profiles of Rupena, Kugti, Garola, and CSIR-IHBT populations were found to be similar during the first day of distillation. However, during the second day, Rupena, Kugti, Khani, and CSIR-IHBT came under the same ellipse of 0.95% coefficient. The results suggest that the population of Kugti is superior in terms of oil concentration (0.35%), with a higher proportion of patchouli alcohol (63% on the first day). Thus, repeated distillation is recommended for higher recovery of essential oil. Moreover, repeated distillation can be used to attain V. jatamansi essential oil with differential and perhaps targeted definite chemical profile.

A comparison of essential oil extraction from the leaves of lemongrass (Cymbopogon nardus L.) using two microwave-assisted methods

The extraction of essential oils from Lemongrass leaves (Cymbopogon nardus L.) has become more promising than ever before due to the oils' increasing demand in the market in addition to the dynamic breakthrough in its technology advancement. This study presents a comparison of two different methods of microwave-assisted essential oil extraction, namely Microwave Hydrodistillation (MHD) and Solvent-Free Microwave Extraction (SFME), both of which exhibit a better quality in terms of essential oil recovery compared to the conventional extraction methods. This study investigated the effect of extraction time, microwave power, as well as feed-to-distiller volume ratio (F/D). Experimental results suggest that although there is a tendency to increase yield along with the increasing power, the yield turns out to decrease at higher power, with the optimum power for the MHD method being 420 W and that of the SFME method being 560 W. Smaller F/D ratios appear to give higher yields for both methods and the smaller the size of the material, the higher the yield obtained. The MHD method produces a smaller yield but has a better quality of citronella oil compared to the SFME method. Two first-order and second-order extraction kinetics models were compared for both the MHD and SFME methods, and the results suggest that the first-order model was slightly better at representing the experimental data based on the RMSD and R2 values. This applies to both experimental data using the MHD and SFME methods, respectively.

Recent advances in valorization of citrus fruits processing waste: a way forward towards environmental sustainability.

Citrus fruits are well known for their medicinal and therapeutic potential due to the presence of immense bioactive components. With the enormous consumption of citrus juice, citrus processing industries are focused on the production of juice but at the same time, a large amount of waste is produced mainly in the form of peel, seeds, pomace, and wastewater. This waste left after processing leads to environmental pollution and health-related hazards. However, it could be exploited for the recovery of essential oils, pectin, nutraceuticals, macro and micronutrients, ethanol, and biofuel generation. In view of the importance and health benefits of bioactive compounds found in citrus waste, the present review summarizes the recent work done on the citrus fruit waste valorization for recovery of value-added compounds leading to zero wastage. Therefore, instead of calling it waste, these could be a good resource of significant valuable components, in this way encouraging the zero-waste theory.

Single-step recovery of pectin and essential oil from lemon waste by ohmic heating assisted extraction/hydrodistillation: A multi-response optimization study

The main products obtained from citrus wastes are pectin and essential oil. In this work, ohmic heating assisted extraction/hydrodistillation (OHAE/H) was applied for the simultaneous recovery of pectin and essential oil from lemon waste. Optimum OHAE/H conditions to maximize the yield of pectin and essential oil were determined with response surface methodology. Three independent variables, namely liquid to solid ratio (w:v), extraction/hydrodistillation time (min) and voltage gradient (V/cm) were varied to obtain maximum pectin and essential oil yield. Optimum OHAE/H conditions were determined as 8.7:1 liquid to solid ratio, 58.4 min extraction/hydrodistillation time and 14.2 V/cm voltage gradient. The predicted pectin and essential oil yields at optimum conditions were 16.58 and 3.62 g/100 g lemon waste, respectively. Data analysis showed that all of the independent variables significantly affected the pectin and essential oil yield. In the verification study, close agreement was found between predicted and experimental values. Conventional heating extraction/hydrodistillation (CHE/H) were conducted to evaluate the effectivity of OHAE/H. With OHAE/H process, the yields of the pectin and essential oil were significantly increased when compared to CHE/H. Limonene concentration of the essential oil produced with OHAE/H was higher than the essential oil produced by CHE/H. Results demonstrate that the single-step OHAE/H could be an effective method for simultaneous extraction and hydrodistillation of pectin and essential oils.

Mexican Oregano (Lippia graveolens Kunth) as Source of Bioactive Compounds: A Review.

Lippia graveolens is a traditional crop and a rich source of bioactive compounds with various properties (e.g., antioxidant, anti-inflammatory, antifungal, UV defense, anti-glycemic, and cytotoxicity) that is primarily cultivated for essential oil recovery. The isolated bioactive compounds could be useful as additives in the functional food, nutraceuticals, cosmetics, and pharmaceutical industries. Carvacrol, thymol, β-caryophyllene, and p-cymene are terpene compounds contained in oregano essential oil (OEO); flavonoids such as quercetin O-hexoside, pinocembrin, and galangin are flavonoids found in oregano extracts. Furthermore, thermoresistant compounds that remain in the plant matrix following a thermal process can be priced in terms of the circular economy. By using better and more selective extraction conditions, the bioactive compounds present in Mexican oregano can be studied as potential inhibitors of COVID-19. Also, research on extraction technologies should continue to ensure a higher quality of bioactive compounds while preventing an undesired chemical shift (e.g., hydrolysis). The oregano fractions can be used in the food, health, and agricultural industries.

Essential oil extraction from onion using ethanol and CO2 as an extraction fluid mixture

Introduction: Essential oils are volatile chemical compounds, widely known by their fragrance, as well as by antimicrobial and antioxidant activities. These oils are generally extracted from aromatic plants in procedures using conventional solvents. Methods: In this study, essential oil was extracted from onion (previously chopped and dried) using a mixture of ethanol and CO2 as the extraction fluid. The essential oil obtained from the extraction was collected and purified and the mass was determined (by weighing) to evaluate the effect of CO2 flow on the yield. The essential oil extracted and purified was characterized to determine the acid and refraction indexes, viscosity, and specific mass. Results: The values obtained for refraction and acid indexes are within limits and similar to the average reported in literature. In all cases, when the CO2 was used, there was an increase the essential oil recovery. In terms of quality, the products from this process were characterized to determine the density, acid index and refraction index. The results obtained were similar to those published in the literature. Discussion: The proposed apparatus and CO2 methodology can be considered a good alternative to boost the extraction of essential oil aiming the obtaining of new products for use as raw materials in different industrial processes. Since this apparatus presents more than double extraction yield than Soxhlet experiment.

Genetic improvement of palmarosa (Cymbopogon martini var. motia) for herbage yield and essential oil quality through polycross system of breeding

Palmarosa is one of the commercially important essential oil yielding crops of India. Improving the herbage and essential oil yield through appropriate breeding methods is the major objective of this crop. Being a cross pollinated crop, its improvement can be made through mass selection. Fifteen best palmarosa clones are identified from two years of individual plant screening of seven germplasm material for different growth, yield and quality parameters formed the base material for this study. The slips of fifteen selected clones were planted in the polycross nursery at ICAR-DMAPR, Anand, Gujarat. The composite hybrid seeds of palmarosa were collected separately from each clone from the polycross nursery. In the present study, the performance of composite hybrids along with check was evaluated to identify best performing polycross hybrids for herbage and essential oil yield. Two hybrids DCMH 8 and DCMH 10 had more than 22 per cent higher dry herbage yield than the commercial variety Trishna. The polycross hybrid progeny proved to be significantly superior with respect to essential oil content and percentage of essential oil recovery. Among the hybrids DCMH 8 had the highest oil yield (16.08 g/plant), which was 37.79 per cent higher than check variety. Based on the performance of the polycross composite hybrids, top performing five hybrids viz., DCMH 1, DCMH 6, DCMH 8, DCMH 10, and DCMH 14 were selected and advanced to multi-location trials across different centers to identify the best one for release as a commercial composite variety. Key wordsPolycross breeding, half sib, palmarosa, composite hybrids, essential oil yield.