Microwave-assisted Steam Distillation Research Articles

The Preparation of the Essential Oil from Pomelo (Citrus maxima ‘Shatian Yu’) Peel Using Microwave-Assisted Distillation by Pectinase Soaking and Its Anti-Fungal Activity

To verify the anti-fungus properties of the crop-harmful pseudocercospora, the essential oil (EO) of pomelo peel (PP) was extracted by a single factor combined with response surface optimization. Meanwhile, the composition and activity of EO were studied. The PP was squeezed by a screw extruder and pretreatmented by pectinase, then extracted by microwave-assisted steam distillation. The optimal conditions were as follows: pectinase dosage was 69.17 μmol/g, microwave power was 651.42 W and extraction time was 43.84 min. The dry weight (DW) yield of PPEO reached 14.63 mL/kg DW after BBD optimization. There were 23 compounds in the PPEO identified by GC-MS. Limonene, α-phrenbutene, and laurene in PPEO accounted for 79.31%, 4.72%, and 3.46%, respectively. In addition, the antifungal was effective when the concentration of PPEO was 3.5 mg/mL. Therefore, this study has guiding significance for the development of natural resources.

Optimization of operating parameters in extraction of essential oils from Lavandula angustifolia flowers by microwave assisted steam distillation

Optimization of operating parameters in extraction of essential oils from Lavandula angustifolia flowers by microwave assisted steam distillation

Improved method to obtain essential oil, asarinin and sesamin from Asarum heterotropoides var. mandshuricum using microwave-assisted steam distillation followed by solvent extraction and antifungal activity of essential oil against Fusarium spp

An efficient microwave-assisted steam distillation followed by a solvent extraction method (MSDE) was established to isolate the essential oil, asarinin and sesamin from the roots and rhizomes of Asarum heterotropoides var. mandshuricum (AHVM). In the MSDE technology applied in this work, moistened roots and rhizomes of AHVM powders are applied to this system. After extracting the essential oil by steam distillation, the powder residue of the roots and rhizomes of AHVM is relatively dry. Hence, this method can save energy consumption, and the loss of asarinin and sesamin can be reduced during the subsequent extraction process and improve essential oil yield. The developed method extracted the essential oil to reach the maximum extraction amount (15.80 ± 0.79 mL/kg) after microwave irradiation for 30 min and maintained the yield balance. Through comparison, MSDE was chosen as the best approach, and under the optimum conditions (90 % aqueous ethanol, liquid–solid ratio of 19.0 mL/g and microwave irradiation power of 332 W) obtained by first order kinetic models and response surface analysis with Box–Behnken design, satisfactory yields of asarinin (1.81 ± 0.72 mg/g) and sesamin (0.74 ± 0.09 mg/g) were achieved. In accordance with the yields of asarinin and sesamin, our research optimized the process parameters. According to the comprehensive comparison of these parameters, the proposed process described in this study has greater advantages than traditional methods. Minimum inhibitory concentrations (MICS) of the essential oil, which obtain from the roots and rhizomes of AHVM of five kinds of Fusariums spp. (F. avenaceum, F. trichothecioides, F. sporotrioides, F. sambucinum and F. culmorum) were determination to be 1.25 mg/mL, 1.5 mg/mL, 1.5 mg/mL, > 2 mg/mL and > 2 mg/mL, respectively. The results of the antifungal test showed that the essential oil from the roots and rhizomes of AHVM showed remarkable antifungal activities, in which, F. avenaceum was the most sensitive to the essential oil, with the MIC50 values of 0.625 mg/mL.

GC-MS analysis of volatiles in cinnamon essential oil extracted by different methods

Cinnamon essential oil (CEO) was extracted by three different methods: steam distillation (SD), ultrasound-assisted steam distillation (UASD) and microwave-assisted steam distillation (MASD). The volatiles in CEO were separated and identified by gas chromatography–mass spectrometry (GC-MS), and the differences in volatiles among the three different methods were further analyzed through principal component analysis. The results showed that 36 individual volatile components were present in the CEO from the three different methods. In general, the numbers of aldehydes, esters, alcohols, terpenes, aromatics and ketones were 6, 3, 7, 17, 2, and 1, respectively. The most abundant volatile component was determined to be cinnamic aldehyde. The content of total cinnamic aldehydes, which determines the price of CEO, was the highest among the three methods in the UASD sample (85.633%). Moreover, the highest yield (8.33‰) of essential oil was extracted by the UASD method. Therefore, UASD was the best way for CEO extraction in this research and was recommended for future industrial applications.

A novel microwave-assisted steam distillation approach for separation of essential oil from tree peony (Paeonia suffruticosa Andrews) petals: Optimization, kinetic, chemical composition and antioxidant activity

Microwave-assisted steam distillation (MSD) was developed as an efficient technique for the separation of essential oil (EO) from tree peony (Paeonia suffruticosa Andrews) petals, on the basis of ensuring the extraction of flavonoids. During MSD process, the raw material was separated from water to keep it in a relatively dry state, thus contributing to the subsequent extraction of flavonoids. In this work, the optimization of MSD process was conducted to obtain the optimum conditions (1.7 mL/g water ratio for soaking, 1 h soaking time, 540 W microwave irradiation power and 30 min microwave irradiation time) and high yield of EO (0.66 ± 0.03 mg/g). The MSD technique was compared with other reference methods in terms of kinetic model fitting, economic value, environmental impact, EO composition and antioxidant activity. The result pointed out that the MSD method could be reasonably fitted by first-order kinetic model, was environmentally friendly and economically sustainable, provided higher separation efficiency, required lower energy consumption, and had certain advantages in the separation of EO with higher proportion of oxygenated components and better antioxidant activity. Furthermore, microwave-assisted extraction (MAE) of flavonoids from the petal residues obtained after MSD showed better result than that obtained after microwave hydrodistillation, and the result was comparable with MAE and heat reflux extraction. Overall, MSD is a potential and powerful alternative to traditional methods for the efficient distillation of EO, on the premise of reducing the loss of flavonoids etc. non-volatile components.

Optimization of Extraction Process of Valeriana officinalis L. Root Essential Oil and Study on Its Anti-Free Radical Activity

Taking Valerianrhizome as raw material and the yield of volatile oil of Valerian as an index, the extraction process of valerian volatile oil was analyzed by microwave assisted steam distillation, and optimized by Box-Behnken response surface test. The effects of scavenging capacity of Li, DPPH and hydroxyl radicals on their antioxidant capacity were studied. The results showed that the optimal process conditions of microwave extraction of volatile oil of Valerian were 350W microwave power, extraction time 25min, liquid-to-material ratio 8.8mL: 1.0g, and the yield of volatile oil of Valerian extracted under this condition was 5.88%. Microwave-extracted volatile oil of Valerian has strong scavenging ability and high reducing power to DPPH free radicals and hydroxyl free radicals. Compared with steam distillation, it has obvious differences, which can provide reference for the development of antioxidant products of Valerian oil.

Chemical composition, kinetic study and antimicrobial activity of essential oils from Cymbopogon schoenanthus L. Spreng extracted by conventional and microwave-assisted techniques using cryogenic grinding

In this present work, volatile oils from Cymbopogon schoenanthus L. Spreng’s (CS) leaves extracted by microwave assisted hydrodistillation (MAHD) and microwave assisted steam distillation (MASD) were studied according to simple (SG) and cryogenic grinding (CG) and compared with conventional hydrodistillation (HD).Extraction time, kinetics, energy consumption, CO2 rejected, physical properties, chemical composition and antimicrobial activity were investigated for the first time with this specie using microwave extraction and showed that MAD is a promising and innovative technique for extraction of volatile oils; also, cryogenic grinding allowed a high extraction yield compared to the classical grinding (MAHD-CG: 1.76% - MAHD-SG: 1.25%) and (MASD-CG: 1.5% - MASD-SG: 1.11%). GC and GC–MS analysis showed variability in composition according to the technique used especially in major constituents and in chemical classes.Qualitative and quantitative kinetic study demonstrated a significative effect of extraction technique and grinding mode on aromatic profile.Evaluation of antimicrobial activity showed that the efficiency of volatiles from CS varied according to extraction technique used where MASD-SG volatile was the most effective one.

Penicillium expansum Inhibition on Bread by Lemongrass Essential Oil in Vapor Phase

The antimicrobial activity of lemongrass (Cymbopogon citratus) essential oil (EO) in the vapor phase on the growth of Penicillium expansum inoculated on bread was evaluated, followed by a sensory evaluation of the bread's attributes after EO exposure. The lemongrass EO was extracted from dry leaves of lemongrass by microwave-assisted steam distillation. The chemical composition of the lemongrass EO was determined using a gas chromatograph coupled to a mass spectrometer. The refractive index and specific gravity of the EO were also determined. Bread was prepared and baked to reach two water activity levels, 0.86 or 0.94, and then 10 μL of P. expansum spore (106 spores per mL) suspension was inoculated on the bread surface. Concentrations of lemongrass EO were tested from 125 to 4,000 μL/Lair, whereas mold radial growth was measured for 21 days. For sensory evaluation, breads were treated with lemongrass EO vapor at 0, 500, or 1,000 μL/Lair for 48 h and tested by 25 untrained panelists. The EO yield was 1.8%, with similar physical properties to those reported previously. Thirteen compounds were the main components in the EO, with citral being the major compound. P. expansum was inhibited for 21 days at 20°C with 750 μL of EO/Lair, and its inhibition increased with increasing concentrations of EO. Sensory acceptance of bread exposed to vapor concentrations of 500 or 1,000 μL of EO/Lair or without EO was favorable; similar and no significant differences (P > 0.05) were observed among them.

Extraction of Essential Oils from Citrus By-Products Using Microwave Steam Distillation

The main objectives of this research is to extract essential oil from: orange ( citrus sinensis), lemon( citrus limon) and mandarin( citrus reticulata) peels by two methods: steam distillation (SD) and microwave assisted steam distillation (MASD), study the effect of extraction conditions (weight of the sample, extraction time, and microwave power, citrus peel type) on oil yield and compare the results of the two methods, the resulting essential oil was analyzed by Gas Chromatography (GC).
 Essential oils are highly concentrated substances used for their flavor and therapeutic or odoriferous properties, in a wide selection of products such as foods, medicines and cosmetics. Extraction of essential oil is one of the most time and effort consuming process. Microwave-assisted extraction is a green technique for the extraction of natural products. (MASD) was better than (SD) in terms of rapidity, energy saving and yield. (MASD) gave higher yield than (SD) with shorter extraction time, yield of orange oil extracted by (MASD) was (1.150%) in (35min.) compared to (1.095%) in (45min.) by (SD) process, same results obtained for lemon and mandarin.
 The optimal microwave power was (135W) gave oil yield: (1.150%, 1.115%, 0.940%) for orange, lemon and mandarin respectively, (MASD) increased extraction temperature in short time and to a higher level compared to (SD). The optimal weight was (398.56gm) gave yield in (SD): (1.095%) and MASD (1.091%) for orange oil, same results obtained for lemon and mandarin. The best citrus peel type which gave the highest yield was orange followed by lemon then mandarin in both processes.
 Limonene is the most abundant component in citrus essential oil, (GC) analysis showed that (SD) was more convenient to give high amount of limonene because of the graduate temperature rise, while in microwave extraction exposure to low microwave

Research on the Extraction of Dendranthema Morifolium Volatile Oils by Microwave-Assisted Steam Distillation Extraction

Microwave-assisted steam extraction system combines the advantages of both conventional and modern technologies. MAE is probably going to be the leading technology in essential oil producing industry. In our research, one-factor and uniform experimental designs are used to determine the optimum extraction conditions, and the results are as follows: the extraction yield is measured as 2.30% with 3h of reflux time, when degree of pulverization is 90, immersing time is 3h, yield of solid to liquid equals 12: 1 ml/g. The chemicals in the production were examined by GC-MS. More than 40 kinds of chemicals were detected, which is consistent with that of the traditional steam extraction method. However, the extraction efficiency is dramatically increased when the steam extraction is assisted with microwave heating, and it is up to 3.8 times.

Rapid, one-pot derivatization and distillation of chlorophenols from solid samples with their on-line enrichment

A microwave-assisted steam distillation (MASD) sample preparation technique for extracting chlorophenols from solid samples was studied. This open vessel microwave system based study developed as an integrated method since it has incorporated extractive distillation, derivatization and on-line enrichment. Gas chromatography (GC) with electron-capture detection was used for the analysis. The study involved optimization of MASD parameters and on-line enrichments using spiked solid samples. MASD achieved recoveries for spiked soil samples in the range of 94–101% within 20 min with a collection of only 20 ml distillate facilitating on-line enrichment. Some real samples were analyzed that included soil, wood, leather, textiles, dyes and certified reference materials of soil and wood samples. Limit of detection values of 12 ng/g for pentachlorophenol and 194 ng/g for monochlorophenol were found. Recoveries of 96.6% in the case of soil certified reference material (CRM) with RSD 2.7% and 80.6% in the case of wood CRM with RSD 3.3% were observed in this study. MASD studied found to produce very clean extracts in comparison to reference techniques.

Microwave-assisted steam distillation for the determination of organochlorine pesticides and pyrethroids in Chinese teas

In this work, microwave-assisted steam distillation (MASD) extraction method followed by gas chromatography/electron capture detection (GC/ECD) was developed for the determination of organochlorine pesticides (OCPs) and pyrethroids in the Chinese teas. MASD is a combination of microwave-assisted extraction (MAE) and steam distillation techniques. Water vapor generated by microwave irradiation is used to accelerate desorption of the analytes from the sample, and the nonpolar organic solvent used for trapping the analytes is kept from direct contact with the sample by the water. Therefore, relatively clean extracts were obtained compared to the method directly using organic solvent as extraction solvent, such as ultrasonic extraction (USE). Microwave power of 200 W and irradiation time of 2 min was found to be the optimum conditions for the MASD process, and n-heptane was chosen as the analyte-trapping solvent in the study. Five OCPs (α-HCH, γ-HCH, dicofol, p, p′-DDE, p, p′-DDT) and two pyrethroids (bifenthrin, fenvalate) were determined using this extraction method in the tea samples. The relative standard deviation (R.S.D.) of the analytes varied from 2.2 to 8.4%, and the method detection limits (MDLs) found were lower than 0.23 μg/kg. The recoveries of the seven compounds in the Jasmine tea sample were between 84.04 and 110.1%. Comparative results obtained by MASD and USE were also discussed in the study.

Microwave-assisted steam distillation for simple determination of polychlorinated biphenyls and organochlorine pesticides in sediments.

A novel sample extraction technique for polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) analysis using microwave-heating device is developed. In this study, microwave-assisted extraction (MAE) and steam distillation techniques were combined. Desorption of the anatytes from solid matrixes was accelerated with water vapor which was generated by microwave irradiation. A sample holder in a commercial microwave extraction cell kept the sample from direct contact with the organic solvent for analytes trapping during the treatment process. Therefore, relatively clean extracts were obtained with small amount of solvents. Without any cleanup steps, the obtained extract could be analyzed with gas chromatograph/mass spectrometers (GC/MS). Six PCB congeners (PCB15, 28, 70, 101, 180, 194, 209) and three OCPs (gamma-HCH, 4,4'-DDE, 4,4'-DDD) in two marine sediment samples (a sediment collected from a bay of Kyusyu Island, Japan, and a certified reference material NIST SRM1944) were analyzed by using this microwave-assisted steam distillation (MASD) technique and another extraction method (exhaustive steam distillation, MAE, and Soxhlet extraction); and comparisons of the results are shown in this report. Although recovery yields of highly chlorinated biphenyls (PCB180, 194, 209) and relatively polar OCPs (gamma-HCH, 4,4'-DDD) were low (30-60%) compared with other analytes (PCB15, 28, 70, 101, 4,4'-DDE; recovery, 80-100%), use of isotope labeled internal standards for the MASD technique gave comparable results with the values obtained by other extraction methods and the certified values in the samples.

Microwave-assisted steam distillation with simultaneous liquid/liquid extraction of pentachlorophenol from organic wastes and soils.

An efficient method for extracting pentachlorophenol (PCP) from organic solid matrices and soils using direct excitation of the fresh samples by microwave energy is presented. Steam-volatile PCP partitioned into the organic solvent n-hexane within the closed extraction vessel, resulting in recovery rates of 85-92% from aged samples. Condensed water provided a boundary layer between extract and sample thus preventing any contact of PCP with and re-partitioning into the sample. Duration of the microwave-assisted process was 35 min. Crude extracts were derivatized by heptafluorobutyric anhydride (HFBA) to improve selectivity and sensitivity resulting in detection limits of 1-2 micro g kg(-1). GC-MS/MS analyses proved that suitable extracts with only minor impurities were obtained. Common sample treatment steps like drying, thorough grinding, frequent transferring, and tedious clean-up, and concentration procedures which all can cause certain losses of analyte were minimized. The efficiency of the method was verified by comparison with an established ultrasonic extraction procedure. This microwave-assisted pressurized steam distillation with simultaneous partition into an organic phase thus provides a streamlined and efficient strategy which requires no additional investment in standard equipment for microwave-assisted extractions (MAE). Degradation of analytes at longer extraction times must be taken into account.