Extraction Yield Of Essential Oil Research Articles

Improving the extraction yield of essential oil from Pimenta dioica (L.) Merr. using Aspergillus niger ATCC 1004 enzyme blend.

The objective of this work was to optimize the application of an enzymatic blend produced by Aspergillus niger ATCC 1004 on the Pimenta dioica fruits for essential oil extraction. The enzyme blend was obtained from the fermentation of cocoa bean shells, an agro-industrial residue. The effects of the enzymatic pre-treatment on the extraction yield, the chemical composition of the oil through gas chromatography, and the fruit structure through scanning electron microscopy (SEM) were assessed. A Doehlert design was used to optimize the process conditions, resulting in an extraction with 117mL of enzyme during 77min, which increased the extraction yield by 387.5%. The chemical composition was not altered, which proves that the enzyme blend preserves the quality of the essential oil extracted. The content of eugenol (70%), the major compound in the P. dioica essential oil, had a great increase in its concentration (560%). The enzyme activity analyses showed the presence of endoglucanase (0.4U/mL), exoglucanase (0.25U/mL), β-glucosidase (0.19U/mL), and invertase (135.08U/mL). The microscopy analyses revealed changes in the morphology of fruit surface due to the enzymatic action. These results demonstrate the great potential of using enzyme blends produced by filamentous fungi from agro-industrial residues for the essential oils extraction of interest for the pharmaceutical and food industries.

Sustainability analysis of orange peel biorefineries

Biorefineries are constantly evolving since new technological advances in enzyme and microbial processes are boosting research for producing new bio-based products. Nevertheless, the step towards real process implementation must overcome a series of stages based on process sustainability in the early design stages. Orange peel (OP) has been profiled as a potential raw material for producing different products. Few studies have estimated the sustainability of OP-based biorefineries considering the upstream influence on the final process performance. This research aims to perform the sustainability assessment of several OP valorization pathways based on experimental data applying the biorefinery concept. Steam distillation and polyphenolic compound extraction prior to saccharification and anaerobic digestion increase the process performance. A glucose concentration and biogas yield of 21.43 g/L (0.44 g/g OP, db) and 415 mL/g SV were obtained, respectively. An essential oil extraction yield of 1.17 g/100 g OP (db) with a d-limonene content of 91.62% was produced. Moreover, hesperidin, apigenin, and naringenin yields of 7.88 mg/g, 0.475 mg/g, and 0.675 mg/g were obtained. An OP-based biorefinery addressed to produce essential oil, polyphenolic compounds, and biogas with a processing 25 tons/day (wb) has a sustainability index of 66.88%, higher than the values obtained with lesser upstream stages. In conclusion, an integral OP upgrading leads to better enzymatic and anaerobic digestion performances, as well as, a high process sustainability.

Extraction of Cinnamomum longepaniculatum deciduous leaves essential oil using solvent-free microwave extraction: Process optimization and quality evaluation

The optimal process conditions for solvent-free microwave extraction (SFME) of essential oils from Cinnamomum longepaniculatum deciduous leaves after moisture conditioning were established by response surface methodology (RSM). A Box-Behnken design (BBD) was applied to evaluate the effects of three independent variables: moisture content (A: 54%–74%), microwave power (B: 300–500 ​W) and microwave time (C: 20–40 ​min), on the extraction yield of essential oil. The compounds of the essential oils obtained by SFME, hydro-distillation and microwave-assisted hydro-distillation (MADE) were identified by gas chromatography-mass spectrometry (GC-MS), and the total lipids of C. longepaniculatum fresh leaves and deciduous leaves were analyzed. The correlation analysis of the response regression model indicated that quadratic polynomial model could be employed to optimize the extraction of essential oil. The optimal extraction condition was A: 58%, B: 400 ​W and C: 28 ​min. In the optimal condition, the maximum extraction yield was 4.475 mL/100 ​g dw and higher than that by MADE. The main compound of the essential oil was eucalyptol (63.54%), and total oxygenated compounds was 78.95%, mainly caused by SFME and the metabolism of endophytic bacteria with decreasing content of phospholipids and fatty acids. Analysis of variance under the extraction condition illustrated high fitness of the model and the success of RSM for optimizing and reflecting the expected process condition. SFME combined with moisture regulation was an effective method for extracting essential oil from C. longepaniculatum deciduous leaves.

Avaliação do rendimento de extração e da composição química do óleo essencial de cinco variedades comerciais de manjericão (Ocimum basilicum L.)

Basil (Ocimum basilicum L.) is one of the most cultivated aromatic species worldwide, being used as a spice and medicinal plant. The literature reports a wide variability in essential oil composition and its extraction yield of varieties of this species due to genetic and environmental factors. The present work aimed to evaluate the yield extraction and chemical composition of five commercial varieties of O. basilicum grown in Caxias do Sul, South Brazil. Ten plants of the varieties ‘Italiano’, ‘Alfavaca verde’, ‘Manolo’, ‘Fraganza’, and ‘Sabory’ were cultivated in a greenhouse at the Campus-Sede of the University of Caxias do Sul. Plant material was collected, and the essential oil was extracted by hydrodistillation for 4 h using a Clevenger apparatus. Essential oil extraction yield was determined at the end of the process, and the obtained oils were sent to chromatographic analysis. Qualitative analysis was carried out by GC/MS, whereas quantitative analysis was performed by GC-FID. Regarding essential oil yield, the ‘Italiano’ and ‘Fraganza’ varieties had the highest extraction yields (1.00 and 0.90% v/w, respectively), whereas the ‘Manolo’ variety had the lowest yield (0.57% v/w). Concerning the chemical composition, the essential oils from the five varieties presented the linalool chemotype, whose contents varied between 47.9 and 79.9 wt.%. The other varieties presented eugenol as the second major compound (5.5-9.1 wt.%), with exception of the oil of ‘Manolo’ variety, which had estragole as the major compound (14.6 wt.%) and the absence of hydrocarbon monoterpenes in the oil. The varieties ‘Alfavaca verde’ and ‘Fraganza’ clustered in both the dendrogram and the PCA, probably due to the same linalool content and the higher 1,8-cineole and lower eugenol contents, whereas the varieties ‘Italiano’ and ‘Sabory’ clustered together, though the linalool contents in these varieties was less similar.

Continuous hydrodistillation-ultrasonication flow batch-mode operation system to enhance essential oil extraction from Satureja khuzistanica and evaluation of in vitro anti-inflammatory activity

Satureja khuzistanica Jamzad (SKJ) is a well-known Persian herbal medicine having valuable biological properties. In this work, a continuous flow batch-mode operation system equipped with a Clevenger apparatus coupled with an ultrasound chamber for intensifying the extraction of essential oil (EO) from dried aerial parts of SKJ has been developed. Response surface methodology (RSM) was then employed to optimize the extraction conditions by considering the interaction of the feed-to-solvent, temperature and sonication time parameters. Gas chromatography (GC) and GC/mass spectrometry (MS) analysis were used to characterize the extracted EO components. The optimal operating conditions for the above parameters was attained at 14.66 g L −1 , 30.86 °C and 39.78 min, consequently. The yield of EO extraction using ultrasound-assisted extraction (UAE) (9.89 mg g −1 of plant) was approximately 25 % higher than that of the conventional method (7.87 mg g −1 of plant). Scanning electron microscopy (SEM) established the effective rifts in the plant cell structures using ultrasound wave irradiation for EO extraction. Moreover, the EO's anti-inflammatory properties were investigated by inhibition of the albumin denaturation analyses. The SKJ's EO extracted under optimal conditions revealed a significant anti-inflammatory effect with 89 % inhibition of the albumin denaturation at concentration of 900 µg mL −1 . • An ultrasonication process was coupled to a hydrodistillation procedure for EO extraction. • Aerial part of Satureja khuzistanica Jamzad SKJ was subjected to UAHDE for EO extraction. • An experimental design technique was employed to optimize the extraction conditions. • EO extraction yield was increased by 25 % and the time was reduced to about 30 min. • The extracted EO of SKJ had anti inflammatory effect comparable to that of diclofenac sodium.

Optimization of extraction process of pine needle essential oil by response surface methodology and its chemical composition analysis

The extraction of essential oil from pine needles was optimized by response surface methodology, and the following optimal conditions were obtained: a fresh pine needle of 100 g, an extraction time of 2 h, a water dosage of 850 mL, and a NaCl concentration of 2.50%. The extraction yield of essential oil was 0.611% under optimal conditions, which was extremely close to the predicted value. The extraction yields of essential oil from needles of 12 common pines in Guangxi were compared. The contents of essential oil in needles of Pinus massoniana, Pinus crassicorticea, and Pinus taeda were relatively higher than other pines. A total of 44 chemical components were identified by GC-MS, including 12 monoterpenes, 14 sesquiterpenes, and 12 alcohols. The chemical components of essential oil from different pines have their own features, and it is speculated that they have good and diversified application potential in the fields of medicine, food, spices, and so on. The chemical compositions of essential oil with high extraction yield have similar characteristics. This phenomenon can be used as the basis and means for the selection of pines with high content of essential oil in needles.

Kinetic modeling of Essential oil extraction from lemongrass acclimatized in Tandjilé in Chad

The Cymbopogon flexuosus species introduced in Congo-Brazzaville (equatorial climate) to solve the low production problem of Cymbopogon citratus, a source of citral, was acclimatized in Chad (subtropical climate) for the same reasons. The plant was perfectly adapted with a very high production of biomass. Its low essential oil extraction yield (0.89% DM) compared to the Cymbopogon citratus local species (1.26%) is very largely balanced by its very high biomass productivity. The extraction of essential oil fits Milojevic's pseudo first order model with rate constant k = 0.0087 min-1 (R2 = 0.9816) for Cymbopogon flexuosus vs k = 0.0109 min-1 (R² = 0.922), for local C. citratus. It also fits Peleg's model with a kinetic constant k1 = 217.94 min %-1 and an extraction capacity constant K2 = 0.6022%-1, which leads to a pseudo first order kinetic constant of hydrodistillation k = k1/K2 = 0.0028 min-1. For local C. citratus, these values are respectively k1 = 108.94 min %-1; K2 = 0.4971%-1 and k = 0.0046 min-1 with R² = 0.9885. Michael Menton's model, which is also fitted, leads to the kinetic constant Km/Ymax = 237 min %-1 and the yield Ymax = 1.9% with R² = 0.9862, for C. flexuosus and Km/Ymax = 113.12 min %-1, Ymax = 2.1% (R² = 0.9952) for C. citratus. These results corroborate those obtained on the same species acclimatized in Congo-Brazzaville.

Research on the optimization, key chemical constituents and antibacterial activity of the essential oil extraction process of Thuja koraiensis Nakai

Thuja koraiensis Nakai is a kind of precious economic tree species with fragrance, ornamental and medicinal functions. The essential oil has the satisfactory antibacterial activity. In this paper, the essential oil from the branches and leaves of Thuja koraiensis Nakai was studied by optimization of extraction process, and the optimized parameters mainly include solid-liquid ratio, NaCl concentration, distillation time, storage conditions, etc. Which provided technical scientific basis for the development and utilization of Thuja koraiensis Nakai. The essential oil from the branches and leaves of Thuja koraiensis Nakai was extracted by steam distillation, and the single factor experiment was carried out. The extraction process of the essential oil from the branches and leaves of Thuja koraiensis Nakai was optimized by response surface methodology. The chemical constituents were analyzed by GC–MS. The antibacterial activity of the essential oil was detected by filter paper and plate coating methods. Thuja koraiensis Nakai showed that when the material-to-liquid ratio was 50 g/400 ml, the NaCl concentration was 6.0%, the distillation time was 5 h,the storage condition was dry branch, the oil content was the highest. The response surface optimization method showed that material-to-liquid ratio was 7.8804 ml/g, distillation time was 2.23 h, NaCl concentration was 6.56%, under such condition, the yield was 1.1712%. The chemical constituents of the essential oil were analyzed by GC–MS (gas chromatography–mass spectrometry), and 45 compounds were detected, accounting for 96.03% of the total number. The bacteriostatic activity was detected by filter paper method. The results showed that the essential oil of Thuja koraiensis Nakai had antibacterial effect on three strains (Staphylococcus aureus, Bacillus subtilis and Escherichia coli), among them, the diameter of bacteriostatic circle against S. aureus, B. subtilis and E. coli was 10.00 mm, 15.20 mm and 9.86 mm. The minimum inhibitory concentration (MIC) of the branches and leaves of Thuja koraiensis Nakai to S. aureus was 5 μg/ml, to B. subtilis was 0.625 μg/ml and to E. coli was 2.50 μg/ml. The highest extraction yield of essential oil from the branches and leaves of Thuja koraiensis Nakai by steam distillation was 1.30%. A total of 45 compounds were identified from the essential oils of Thuja koraiensis Nakai, among which carverol acetate was the highest. The essential oil from the branches and leaves of Thuja koraiensis Nakai has obvious antibacterial effect and great development potential, for example, making insect repell0ents, fungicides, essential oil soaps, so it is recommended to collect and use it.

Plasma bubbling effect on essential oil yield, extraction efficiency, and flavor compound of Cuminum cyminum L. seeds

AbstractPlasma 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.

Experimental design approach in optimization of some effective variables on quantity and quality extraction of essential oil from Rosa damascena Mill

Having fragrant and useful components, essential oil of Rosa damascena Mill. with the common name of Rose otto is the most expensive and valuable natural aroma products in the world. Different products of R. damascena petals has been known as the most important and basic ingredients or additives in the food, drug, perfume and cosmetic industries in many centuries. Amount of the petals essential oil and its composition is a determining factor of products, made from them. Despite this fact, there is no report about optimization of essential oil extraction from Rosa damascena in the literature. In the present study, the effect of different temperatures (− 5, 0, 5, 10 and 15 °C) and duration times of storage (1, 4, 7, 11 and 14 days) on the yield and quality of essential oil extracted from the petals of the mentioned plant was investigated. The response surface methodology (RSM) was used to achieve optimum parameters. It was very interesting to find out storage duration and temperature of 14 days and − 5 °C were optimal conditions to obtain maximum extraction yield of 0.0429%, respectively. This means that despite popular belief, petals storage not only does not reduce the extraction yield of essential oil, but also it increases that by up to 1.5 times when the temperature is controlled. Citronellol to geraniol ratio (C/G) was selected as a criterion of essential oil quality. Based on the related standard from International Standard Organization (ISO), the desired ratio of citronellol to geraniol (C/G) is 1.30; therefore, this value was considered as the optimum response. Surprisingly, it was found that the quality of essential oil from short-term fermented petals is higher than those from fresh petals. Storage temperature of about 0 °C during 1 day was obtained as the optimum values for attaining the best essential oil quality. Results from this study can pull over public believes about necessity of instant essential oil extraction from harvested petals.

Recovery Yield and Bioactivities Evaluation on Essential Oil and Ethanolic Extract of Star Anise (Illicium verum Hook.f.)

This study focused on the extraction of the essential oil and extract from star anise (Illicium verum Hook.f.) and the evaluation of the physicochemical properties and bioactivities of these products. This study was conducted by 'one factor at a time' method on the factors affecting on the extraction yield of essential oil and the antioxidant activity of the extract.

Formulation of a Floor Cleaning Product using Lemongrass (Cymbopogon citratus) Essential Oil and Evaluation of Foamability and Foam Durability

The growing demand for natural products has spurred the idea of replacing synthetic fragrances with essential oils with antibacterial properties. Essential oils distilled from commercially valuable Cymbopogon citratus species has citral as a major component and finds a wide range of application such as flavors and aromas in perfumes, cosmetics, soaps, and detergents and in the pharmaceutical industry. Via hydrodistillation, the extraction yield of essential oil reached 0.29%. The components for formulation of the cleaning product were determined through a survey of active ingredients: 4.5% Sodium Lauryl Ether Sulphate (SLES), Ethylendiamin Tetraacetic Acid (EDTA-2Na), 0.7% Coco Amido Propyl Betaine (CAPB), 1% Hydroxyethylcellulose (HEC), Sodium Benzoate, 0.3% Butylated hydroxyanisole (BHA), 0.1% NaCl and 0.2% lemongrass essential oil. The finished product was evaluated based on the foaming ability and durability of the emulsion. At the same time, samples stored at different conditions (e.g. room temperature, acceleration, thermal shock) were evaluated for its durability. The results show that citronella oil can be used as a valuable cosmetic material, an antibacterial agent, while not adversely affecting the usability of floor cleaning liquid.

Enzyme pretreatment improves the recovery of bioactive phytochemicals from sweet basil (Ocimum basilicum L.) leaves and their hydrodistilled residue by-products, and potentiates their biological activities

In the present study, the effect of enzyme pretreatment on essential oil recoveries from sweet basil (Ocimum basilicum L.) leaves was evaluated. Moreover, the consideration on the use of hydrodistilled residue by-products as a source of bioactive phytochemicals with antioxidant, antimicrobial, and repellent effects against the stored-grain pest Tribolium castaneum was examined. Results showed that the enzymatic pretreatment increased the extraction yield of essential oil by 400, 417, and 478% in hemicellulase-, cellulase-, and viscozyme-treated samples, respectively. Phenylpropanoids including methyl cinnamate, methyl eugenol, eugenol and estragol were found as the main components, and were particularly abundant in cellulase-treated samples. From the hydrodistilled residue of enzyme-treated samples, better recoveries of total phenols (TPC) (258.3–470.9 mg GAE/g extract) and flavonoids (TFC) (59.4–94.3 mg QE/g extract) were observed. Using the DPPH, ABTS, and FRAP assays, a strong antioxidant activity of the rosmarinic-rich extract was observed. Such an activity which was mediated through electron transfer mechanism was highly correlated with the TPC, TFC and rosmarinic acid content. The in vitro bioassay showed that methanol extract (6.29 and 12.58 µL/cm2) had repellent activity against the stored-grain pest Tribolium castaneum. These results suggest the potential of enzyme pretreatment to promote the use of hydrodistilled residue by-products as a valuable source of natural antioxidants and repellents ingredients.

The Study on Extraction Technology of Essential Oil from Tribute Citru

The essential oil from Tribute Citru peel was extracted by steam distillation. The extraction method was studied by single factor test and orthogonal test. According to the experiment results, the order of influence was: distillation time, sodium chloride solution concentration, soaking time, material-liquid ratio. The optimum condition determined by orthogonal test was 3.0% sodium chloride solution in the solid-liquid ratio of 1:16 and distillation time was 1.5h without soaking. Under this condition, the extraction yield of essential oil from Tribute Citru peel reached 9.29%.

Tối ưu hóa hiệu suất trích ly tinh dầu bưởi của thiết bị trích ly dạng pilot

Pomelo essential oil has many applications in cosmetic, medicament and food, thus the research on the pomelo essential oil extraction is concerned by many researchers in the world. Pomelo essential oil was extracted by many extraction methods. In this study, the pomelo essential oil was extracted by using steam distillation method at the pilot scale. The parameters of extraction method such as the mass ratio of pomelo peel to water, the oil temperature in a heating jacket and the extraction time were investigated to seek the maximum yield of recovered essential oil and the maximum extraction yield of essential oil. The obstacles of extraction equipment were then pointed out and the solution was suggested. The research also, then, points out the obstacles of extraction equipment and the solution was suggested. The maximum yield of essential oil and the maximum extraction yield of essential oil were obtained at 0,737‰ and 21,68%, respectively at the mass ratio of pomelo peel to water = 1:5, the oil temperature in a heating jacket of 170oC and the extraction time of 8h. The maximum yield of essential oil and the maximum extraction yield of essential oil in the large scale present the stability and effectiveness operation of extraction equipment and the saving of extraction time.

English

Essential oils are natural substances which can be used as natural conservators for foods. The present work aimed to evaluate biological properties of essential oil of Hyptis suaveolens and its effect on shelf-life of beef. The extraction was carried out by hydro-distillation. Antioxidant activity was determined by method of DPPH and FRAP. Antimicrobial activity was determined by the microdilution and agar diffusion methods. The sensitivity of eleven pathogen microbial strains was tested. The conservation test of ground meat using essential oil was carried out by monitoring the evolution of the microbial groups. Result showed that extraction yield of essential oil was 0.21% (m/v). The DPPH assay gave IC50 of 16.367 ± 0.0739 µL and was confirmed by the FRAP assay. The essential oil from H. suaveolens showed inhibitory activity on microbial strains. Biopreservation assay revealed a significant decrease of microbial charge during conservation time. Thus essential oil was successful in vitro and its activity on prolonging shelf-life of beef was found to be 7 days. The results of the present study demonstrated the possibility of essential oil from H. suaveolens to be used as natural conservator for food industry. Key words: Hyptis suaveolens, essential oil, biopreservation, biological properties, meat.

Effect of drying temperature and storage time on Ocimum gratissimum Linn. leaf essential oil from Central Highlands, Vietnam

Abstract Essential oil of Ocimum gratissimum Linn. leaf is widely used in folk medicine. Extraction yeild, compositions and antioxidant activity of clove basil essential oils could be affected by several factors including drying temperature and storage conditions. The present work evaluated the influence of storage conditions and drying temperature different of Ocimum gratissimum leaves on essential oils from Central Highlands, Vietnam. In this research, fresh leaves were preserved at 4°C for 10 days and dried and then stored at room temperature. Essential oil of Ocimum gratissimum L. was extracted by hydrodistillation and steam distillation methods. The composition of essential oil was determined by using GC-MS, antioxidation activities were conducted by the DPPH method. Drying the material at 45°C only 1% Decrease extraction yield, the extraction yield of essential oil at 45°C is still high (2.5%); the color of the oil when the material is fresh in yellow, characteristic odor, drying at 45°C is pale yellow, mild characteristic odor; Antioxidation resistance change is negligible; Drying the material at 45°C, the content of eugenol (77.389%) increased 3 fold compared with fresh material (24.84%), while the drying loss of some components small proportion in oil.

Optimization of Nepeta Cataria Essential Oil Extraction Yield by Ultrasonic-Soxhlet Extraction Method Using Response Surface Methodology

Essential Oil (EO) of Nepeta Cataria L. has an attractive benefit due to its potential as alternatives compound of controlling mosquito vectors especially Aedes aegypti. This paper reports on application of response surface methodology (RSM) using Box Behnken design (BBD) to optimize the extraction of EO from Nepeta Cataria L. The parameters experimented were the time of extraction (120-360 min), temperature of sonication (30-50°C) and ratio of sample to solvent (30-60gram/150ml). The extraction was conducted by using soxhlet method assisted by ultrasound using ethanol (polar solvent). Statistical analysis and analysis of variance indicated that the time of extraction and ratio of sample to solvent are significant factors (p<0.05) affecting the yield while the temperature of sonication was insignificant (p>0.05). For the modelled extraction, the minimum critical values for ethanol solvent was 269.48 minute, 40.18°C and 33.22 gram/150 ml ethanol. Recovery of oil when 1 gram of raw material was used per 150 ml of solvent was 2.32%. By using High Performance Liquid Chromatography with Ultraviolet detector (HPLC-UV), nepetalactone was detected at time of 12.694 min and 13.941 min using absorption peak 228nm.

Intensification of Essential Oil Extraction of the Marrubium vulgare Using Pulsed Electric Field

This paper is aimed to investigate the application of Pulsed Electric Field (PEF) as a pretreatment step for the intensification of the essential oil extraction yield of Marrubium vulgar that is a local plant from Mascara, Algeria. PEF has been applied for this purpose to improve the permeabilization by electroporation of the biological membranes. The PEF treatment was optimized by using the experiments design methodology, by considering as input factors the voltage level, the pulses number and the distillation process duration. Obtained results have shown that (i) the electrical conductivity of the sample increases due to the enhancement of the mass transfer (ii) the extraction process is significantly improved because the amount of the PEF-treated essential oil has increased up to three times. Moreover, physicochemical analysis of the essential oil carried out before and after treatment has shown that almost all parameters were identified and recovered after treatment.

Extraction Yield of Essential Oil from Lippia graveolens Leaves by Steam Distillation at Laboratory and Pilot Scales

Research on these kinds of plants promotes a beneficial impact on the economy because it addresses the rural and energy crises. In this study, the steam distillation process for obtaining essential oil from Lippia graveolens leaves was evaluated at laboratory and pilot scales. The parameters analyzed were steam flow and bed porosity, and their effects on the extraction yield were determined. The effect of steam flow was found to be an important parameter in steam distillation. The extracts obtained were analyzed by GC-MS. Carvacrol, thymol, and β-cymene constituted the major components of L. graveolens at both scales. The model tested showed a good fit to the experimental data for L. graveolens. The results showed that the greatest yield (4.41 %) was obtained at laboratory scale.