Foliar Structural Aspects and Essential Oil Yield of Two Croton L. Species (Euphorbiaceae) from the Amazon

The importance of essential oils in various industries, such as pharmaceutical, food, and agriculture, has encouraged the development of production from various natural materials. One of the natural materials that produce essential oil is red ginger. Red ginger has the potential to become a local essential oil business because it has a high selling value with its content ranging from 2.58–2.72%. Extraction of essential oil by conventional methods takes longer than the microwave assisted extraction method, but to get purer results, a solventless method called solvent-free microwave extraction is used. In this study, red ginger essential oil was extracted using the solvent-free microwave extraction method with variations in microwave power (low, medium low, medium and high) and extraction time (60, 75, 90, 105 and 120 minutes). This study aims to determine the effect of microwave power and extraction time on yield and characteristics of red ginger essential oil in accordance with SNI 06-1312-1998. The best yield of essential oil was found in the treatment of Low power and 120 minutes. In this result, the yield was 1.90618 ± 0.00807% and the characteristics that have met SNI are light yellow in color and distinctive ginger aroma and density of 0.88164 ± 0.00105 g/mL. FTIR spectrogram showed the presence of O-H, C-O, and C=O functional groups and C=C double bonds. These groups were identified as terpenoid group compounds and several other derivative compounds that undergo oxidation, in this case is a carboxylic acid. Based on GC-MS analysis, the estimated oxidized zingiberene compound is 96.09%. The terpenoid compounds contained can be utilized as antibacterial with the resulting inhibition zone included in the moderate category of 7.6 mm.

Plasma bubbling at solid–liquid mixture is a non‐thermal technology for spice processing to retain its flavors and fragrances. Cumin is a regularly consumed spice with significant medicinal properties and has 2–5% essential oil that imparts the characteristic aroma to the seeds. Plasma bubbling influence at a different voltage (175, 180, and 185 V), exposure time (30, 60, and 90 min), and particle size (whole and 0.5 mm) on the essential oil yield and its subsequent effect on flavor compounds were estimated. Increase of voltage to 185 V and bubbling time to 90 min, cumin essential oil yield and extraction efficiency raised from 2.42 to 3.22% and 55.89 to 74.36% for 0.5 mm size, 3.22 to 4% and 74.36 to 92.37% for whole seeds respectively compared to control. Gas chromatography–mass spectrometry analysis showed 21.27 and 31.48% enhancement in cuminaldehyde content after plasma bubbling compared to control of whole and 0.5 mm seeds, respectively.Practical applicationsAn approach to optimize non‐thermal plasma bubbling process parameters for improving Cuminum cyminum L. essential oil extraction by retaining its flavor compound (Cuminaldehyde) was performed in the present study. Plasma bubbling assisted hydrodistillation method is easy, cost‐effective, and also retains flavor compound in essential oil. The data obtained are valuable to scale up a batch scale plasma bubbling process extraction of cumin essential oil to a large or pilot‐scale system since the results showed a rise in essential oil extraction yield and improvement in cuminaldehyde content.

Anise ( Pimpinella anisum L.) is a spice, an essential oil crop, and a medicinal plant with a long history of use. Anise seed oil is extracted from anise seed through steam distillation. There is no experimentally established optimal time for distillation of anise seed. We hypothesized that the distillation time (DT) can be customized for optimum yield and composition of anise essential oil. In this study, we determined the effect of nine steam DTs (5, 15, 30, 60, 120, 180, 240, 360, and 480 minutes) on essential oil yield and essential oil composition of anise seed. We developed regression models to predict essential oil yield, the concentration of individual constituents, and the yield of these constituents as a function of DT. Highest essential oil yield (2.0 g/100 g seed, 2%) was obtained at 360-minute DT. The concentration of transanethole, the major anise oil constituent, varied from 93.5% to 96.2% (as a percent of the total oil) and generally was high at 15- to 60-minute DT and low at 240- to 480-minute DT. However, the yield of transanethole (calculated from the essential oil yield and the concentration of transanethole in the oil) increased with increasing DT to reach maximum at 360-minute DT. The concentration of the other oil constituents varied significantly depending on the DT, and some of them were higher at the shorter DT than at the longer DT. However, the yields of these constituents were highest at longer DT (either 360 or 480 minutes). DT can be used to obtain anise essential oil with different composition that would benefit the essential oil industry. This study demonstrated the need for providing DT in reports where anise seed essential oil yield and composition are discussed. This article can also be used as a reference point for comparing studies in which different DTs were used to extract essential oil from anise seed.

Extraction of essential oils from five cinnamon leaves and identification of their volatile compound compositions

Artemisia dracunculus L. (tarragon) is a perennial herb in the Asteraceae family, which has a long history of use in culinary traditions. The field experiments was conducted to study the influence of foliar Ca(NO3)2 and KNO3 application on vegetative growth, essential oil yield, content and leaf N, P, K and Ca of tarragon in two harvests. The treatments were performed at four level of foliar Ca(NO3)2 and KNO3 fertilizers (including control (water spray), 2.5, 5 and 10 g l-1) which was set up in a factorial experiment based on Randomized Completely Block Design with three replications. Results showed that foliar Ca(NO3)2 application rates significantly increased plant height, plant width, fresh matter yield, dry matter yield, essential oil content and yield, leaf N, P, K and Ca by an average of 36.2, 41.2, 68.3, 68.6, 23, 88.9,7.5, 16.7, 7.2 and 20%, respectively in first harvest and 50.5, 12.1, 42.7, 65.2, 26.3, 91.8, 11.6, 20.8, 10.2 and 26.9%, respectively in second harvest compared with the control. Also, with increasing the foliar KNO3 rates plant height, plant width, fresh matter yield, dry matter yield, essential oil content and yield, leaf N, P, K and Ca significantly increased by an average of 12.4, 27.6, 121.5, 42.3, 12.4, 75.2, 11.5, 16.7, 9.8 and 21.8%, respectively in first harvest and 26.2, 6.1, 37.8, 49.8, 27, 98.8, 4.2, 16, 42.5 and 6.9%, respectively in second harvest compared with the control. Fresh matter yield, essential oil content, leaf N, P, K and Ca in first harvest and plant height, essential oil yield, leaf N, P, K and Ca in second harvest significantly responded to Ca(NO3)2 and KNO3 interaction. It is evident from the results that Ca(NO3)2 and KNO3 foliar application improved productivity traits, essential oil yield and content and nutrient uptake of tarragon plants.

Introduction: Medicinal plants are rich in active substances and primarily have been used in the manufacture of many drugs. Basil (Ocimum basilicum L.) is one of the important medicinal plants whichbelongs to the Lamiaceae family. Basil essential oil content (between 0.5 to 1.5 percent) varies according to climatic conditions of habitat location. Basilneeds a lot of water during growth period and it is very sensitive to water stress and shows wilting symptoms very soon after water shortage. Iran is located in an arid and semi-arid region which has little precipitation that is not enough for crop water requirements. Nowadays, the use of superabsorbent polymers is one of the ways to create sustainable agriculture and increase irrigation efficiency. They can store high water or aqueous solutions in root zone of plants and to reduce negative effects of drought stress. So, improvement of plant growth, increasing of irrigation intervals, reducing water loss and costs of irrigation is due to the application of superabsorbent polymers. Mucilages are also the herbal polysaccharides, soluble in water, and commonly include carbohydrates and can be used as hydrophilic polymers. The aims of this investigation were to study the effects of hydrophilic polymers on water use efficiency, morphological characteristics (dry matter, leaf area, and leaf number), essential oil quantity and yield of basil to harden plant to drought stress and to evaluate its potential to cultivate in arid regions. In addition, taking steps forward towards sustainable agriculture, by reducing the cost of agricultural production, helps protecting the environment. Materials and Methods: This research was conducted as a pot experiment at the department of Horticultural Science‚ college of Agricultural‚ Ferdowsi University of Mashhad‚ Iran, during 2012-2013.The research was set out in a factorial experiment on the basis of completely randomized block design with three replications.Two hydrophilic polymer Stockosorb® (industrial) and malva leaf (herbal) with two application methods (mixed with soil, mixed with soil+root) at 4concentrations (0, 0.1%, 0.2% and 0.3% w/w) were used. Leaf number, leaf area, dry matter yield, water use efficiency, essential oil quantity and yield were measured. Improved seeds of Ocimum basilicum var. Keshkeniluvelou were sown and seedlings were transplanted to the pots in four-leaf stage. Hydrogels were prepared and mixed with water after weighing the polymers according to determined concentration. After establishment, all pots were irrigated with a determined amount of water after reaching to the highest concentration (0.3%) of the wilting point. So, in this state in addition to the treatment at 0.3% treatment, lower levels (0.2% and 0.1%)were reached to wilting point earlierand were exposed to water stress. Results and Discussion: Superabsorbent polymers can by absorption of irrigation and rain water, prevent deep percolation of water and with decreasing irrigation interval and reduced water consumption and increase water use efficiency. The results showed that using Stockosorb superabsorbent polymer and malva leaf as herbal hydrophilic polymersare useful for water supply of the plant in water stress.Application of these substances on morphological characteristics, water use efficiency and basil oil, were superior to the control.According to the obtained results, malva leaf use in soil and roots in treatmentless than (0.1% and 0.2%)number and leaf area and higher than (0.3%)increased dry matter yield, water use efficiency and the essential oil quantity and yield. Stockosorb (0.2%) byboth applying methods increased dry matter yield and water use efficiency. Also Stockosorb (0.2%),soil application increased leaf number and area. The essential oil yield and quantity increasedwith use of Stockosorb in soil + root in for0.2% and 0.3% treatments, respectively. Conclusion: Due to the importance of cultivation of medicinal plants to provide conditions to increase essential oil yield and quantity at the same time, the best method used were malva leaf and Stockosorb with concentrations higher than (0.3%) and soil application methodor the use of both polymers with application method in soil + root in the moderate concentration (0.2%).For that purpose, we obtained favorable conditions for improving the morphological characteristics, water use efficiency and increasing the quantity and of essential oil yield in drought stress simultaneously. The results showed that natural compounds can be a good alternative for chemical compounds, but further experiments are needed for their commercialization.

Chemical composition and antioxidant activity of essential oils from barks of Pinus pumila using microwave-assisted hydrodistillation after screw extrusion treatment

Com o objetivo de avaliar o comportamento agronômico, o potencial de rendimento de óleo essencial e identificar os quimiotipos de 16 acessos de Lippa alba (erva cidreira) da coleção da Universidade de Brasília foi conduzido um experimento de campo em Latossolo Vermelho, sob irrigação por gotejamento na região do Cerrado do Distrito Federal. Foram avaliados a época de florescimento, hábito de crescimento, área foliar, comprimento da haste, massa fresca de folhas e hastes, massa foliar seca, teor e rendimento de óleo essencial e perfil aromático. O óleo essencial foi extraído por hidrodestilação em aparelho de Clevenger modificado e os constituintes identificados e quantificados através de cromatografia em fase gasosa acoplada a espectrometria de massas. O delineamento experimental utilizado foi de blocos ao acaso, com três repetições, contendo três plantas úteis por parcela. Foram identificados os quimiotipos citral-limoneno, citral-mirceno, limoneno-carvona, citral, linalol, mirceno e linalol-limoneno. Os acessos apresentaram teores máximos de linalol de 89,8% (L.16); mirceno de 47,6% (L.37); limoneno de 36,0%, carvona de 46,9% (L.27) e citral de 56,7% (L.17). Os genótipos com maiores áreas foliares e maiores comprimentos de hastes tenderam a apresentar maiores teores de óleo e maior concentração de linalol. A concentração de óleo foi inversamente proporcional à produção de massa foliar seca. Os acessos que apresentaram os maiores rendimentos dos compostos majoritários do óleo essencial foram: L.16 (0,77 g pl-1), como fonte potencial para a produção de linalol; L.17 (0,17 g pl-1), como fonte de mirceno; L. 27 (0,17 g pl-1), como fonte de limoneno e de carvona (0,21 g pl-1) e L.38 (0,24 g pl-1), como fonte de citral.

This study systematically investigated the effect of hydrodistillation (HD) on the yield of essential oil derived from Cyperi Rhizoma following ultrasonic pretreatment using natural deep eutectic solvents (NADESS) as the medium. The parameters for ultrasonic pretreatment were analyzed using single-factor experiments and response surface methodology (RSM) to optimize the yield of essential oil. The findings indicated that the ideal settings for ultrasonic pretreatment were as follows: The water content of NADES-5, with a molar ratio of lactic acid to choline chloride of 3.25:1, was 38.6%. The ultrasonic treatment duration was 42.0 min, the ultrasonic power was 73.0 W, and the actual essential oil yield attained 1.341%. Scanning electron microscopy (SEM) analysis revealed that the application of NADES-5 as the extraction medium resulted in considerable degradation of the powder’s composition, as evidenced by the presence of numerous tiny pores on the surface. This suggested that NADES-5 enhanced permeability and exerted an erosive impact, efficiently dismantling the plant cell wall. Gas chromatography-mass spectrometry (GC-MS) analysis identified 33 distinct components in the essential oil extracted via HD following ultrasonic pretreatment using NADES-5 as the solvent. This study illustrated that employing NADESs as the medium for ultrasonic pretreatment markedly improved the yield of essential oil derived from Cyperi Rhizoma, presenting a novel approach for effective essential oil extraction.

Extraction of essential oil from rosemary leaves: optimization by response surface methodology and mathematical modeling

5 Abstract: Peppermint (Mentha piperita L.) is one of the most important plants producing essential oil. An experiment was carried out using a randomized complete block design with 3 replications to study the effect of salinity stress on growth parameters, essential oil constituents and yield of peppermint. Full-strength Hoaglund's solution containing 0, 50, 100 and 150 mmol L NaCl was applied in irrigation plantings for 4 1 months in a greenhouse. The results showed that salinity stress significantly affected Stem length, root length, shoot wet weight, root wet weight and shoot dry weight, root dry weight, Internodes length, stolon length, biomass, Essential oil yield and Essential oil percent in P < 0.05. An increase in the salinity lead to reduce in length of stem and root, fresh weight of stem and root, dry weight of stem and root, internodes length, total biomass and essential oil percent and yield. It is necessary to mention that peppermint did not tolerate 150 mmol L NaCl and died under this condition. The highest values of growth parameters and essential 1 oil percent and yield were observed under non-salinity condition (control). Also, the highest values of Mentone were obtained under non-salinity condition (control) by using GC-MS.

ABSTRACTFor the production of essential oils and aromatics to be possible throughout the year, it is necessary to continuously supply the plant raw material to the industry or store the plant material for a designated time. However, to allow the plant material to remain in storage with a high quality, it is essential to reduce its water content by drying. This has motivated the oil extraction industries to demand a better yield and quality from the drying process and raw materials, necessitating fast and efficient evaluation parameters. Thus, the aim of this study was to develop an electric conductivity test for evaluating the quality of aromatic and medicinal plants and to quantify the essential oil yield of the dry vegetable material. The drying experiments were conducted at different temperatures and air velocities by altering the control of the drying conditions. Various aromatic plants with different plant mass, volume of deionized water, and temperature of the vegetal material were examined by the electric conductivity test. The qualities of the fresh and dry plants were compared through these tests and yields of essential oil. Increase in the drying air temperature influenced the increase in the dehydration rate of the aromatic and medicinal plants. Higher drying temperatures decreased the physical quality as evaluated by the electric conductivity test and essential oil yield of the aromatic and medicinal plants. The parameters for validation of the electric conductivity test methodology in aromatic and medicinal plants were defined as an exposure time of 33 h, 5 g of fresh plant material in 75 mL of deionized water, 1 g of dry plant material in 50 mL of deionized water, and temperature of 25°C. The electric conductivity test was demonstrated as an appropriate method to be used in the quality control of aromatic plants in essential oil extraction industries. The use of the electric conductivity test will enable the oil extraction industry to monitor the yield and quality of the essential oils extracted from the aromatic plants after drying and storage.

The main objective of the present study is to introduce a new and ecologically safe method for managing the rice weevil, Sitophilus oryzae. Therefore, Eucalyptus salubris leaves essential oils yield, chemical composition and its insecticidal activity against the adults of S. oryzae were evaluated. Moreover, a comparison of innovative and conventional extraction methods of Eucalyptus salubris essential oils collected from two arboreta in south of Tunisia (Zrig and El-Hamma) was investigate. In fact, results demonstrated that essential oils yields varied depending on the arboreta and extraction methods. Essential oils yields obtained with MAE were increased in both arboreta. Besides, results showed a significant positive association between the essential oils yields of MAE and altitude of the arboretum. These results can be used to improve the production of oils in commercial plantations. Analysis of essential oils has shown that chemical composition may differ not only in the quantity of the different compounds but also in the quality of molecules extracted, depending on the method of extraction and harvest area. Moreover, E. salubris essential oils from El-Hamma were rich in hydrocarbon monoterpenes (56%), while those from Zrig were rich in oxygenated monoterpenes (39.6%), mainly 1, 8-Cineole (30.94%). Furthermore, the fumigant toxicity varied with the harvest area, extraction process, oil concentration and exposure duration. The conventional method achieved the best performances. The Lethal Concentration (LC50) values were 25.96 μL/L air, 34.43 μL/L air and 46.74 μL/L air for E. salubris essential oils collected from El-Hamma and extracted by hydrodistillation, ultrasonic-assisted extraction and microwave-assisted extraction, respectively. Overall, extraction of essential oils out by different techniques and innovative methods avoids shortcomings of content optional techniques friendly to environmental to avoid chemical risk, extraction time and obtain yield quality of essential oils.

To evaluate the effect of water stress on yield and storage capability (essential oil percentage, yield and harvest index during five years storage period) of Matricaria chamomilla L., a field experiment was conducted in 2005. Water stress treatments of irrigation after 30, 60, 90 and 120 mm evaporation from pan class A, were arranged as randomized complete block design with six replications. The harvested material was stored for five years and essential oil was extracted yearly. Results of the first year of experiment indicated that the highest (1347 kg/ha and 10084 g/ha) and lowest (952.2 kg/ha and 6672 g/ha) yields of dried flower and essential oil were obtained from irrigation after 60 and 120 mm evaporation from pan, respectively. Results from stored plant material (5-year data of storage) showed a significant effect during storage on essential oil percentage, yield of essential oil, harvest index of essential oil, reduction of essential oil percentage and yield. Means comparisons from the 5-year data indicated that the highest percentage and yield of essential oil (0.715% and 8442 g/ha) was observed at first year. After that, there was a 27% reduction trend in essential oil percentage to the 5-year storage result. So, the lowest essential oil content and yield (0.194% and 2335 g/ha) was obtained from flowers at the fifth year of storage. Key words: Chamomilla recutita, dried flower yield, excess water, storage quality, water deficit.

The objective of this research was to evaluate the effect of successive harvesting times and shading on the production of biomass, yield and phytochemical composition of essential oil in leaves and inflorescences of soilless grown Lavandula dentata. Plants were grown in pots filled with sand, inside a polyethylene greenhouse, in a closed system at UFSM. Plants were harvested at 150, 213 and 320 days after planting date (DAP) in winter, spring and summer, respectively. At 150 DAP, a 50% shading screen was installed. The experimental design was a randomized 3x2 factorial in subdivided plots with 36 plants per subplot. Fresh (FM) and dry mass (DM), yield and chemical composition of essential oil in leaves and inflorescences were determined after each harvest date. The essential oil was extracted, using 70 g fresh mass of leaves and of inflorescences, respectively. Identification and quantification of compounds in the essential oil were determined by gas chromatography/mass spectrometry (GC/MS). The FM of inflorescences was higher on plants harvested 213 DAP grown without shading while of leaves it was higher on plants harvested 320 DAP grown without shading. The yield of the essential oil was higher in the leaves of plants harvested 320 DAP grown without shading. Thirty-one compounds were identified and quantified, being the major ones 1.8 cineol, camphor and linalool, without significant difference among treatments. Three consecutive harvests can be made in August (150 DAP), October (213 DAP) and February (320 DAP) without replacing plants.