Microwave-assisted Hydrodistillation Method Research Articles

Comparative study of the chemical composition and the antioxidant, antidiabetic, anti-inflammatory and cytotoxic activities of Citrus aurantium essential oils extracted by conventional hydrodistillation and microwave-assisted hydrodistillation methods from Algeria

This study aims to evaluate the antidiabetic, anti-inflammatory, cytotoxic, and antioxidant properties of essential oils obtained from the peels of Citrus aurantium and extracted with MAHD and HD. The various compounds detected include limonene and linalol. In this context, we used the methods of bovine serum albumin anti-denaturation to evaluate the anti-inflammatory property and glucose uptake by yeast cells to evaluate the antidiabeticone. The results of evaluating the antidiabetic and the anti-inflammatory activities indicate that the essential oil extracted by MAHD has greater efficiency compared to the essential oil extracted by HD. Besides, the antioxidant potential of the essential oil was evaluated using the DPPH free radical scavenging, reducing power, and β-carotene/linoleic acid tests. Results show that the essential oil extracted by HD presents a high antioxidant activity. Moreover, essential oil is a potential source of important bioactive compounds and of possible synergistic effects among its components. To support the phytochemical analysis, an attempt was made to identify some potential compounds from Citrus aurantium essential oils that can inhibit important drug targets like bovine serum albumin (BSA), cyclooxygenase-2 (COX-2), and tubulin using molecular docking and molecular dynamics simulation methods.

Microwave Assisted Hydrodistillation Essential Oil from Lime Peel Waste as Aromatherapy Candles

Flavonoids belong to the extensive group of polyphenol compounds. They can function as antioxidants and antibacterials by denaturing bacterial cell proteins and damaging bacterial cells. One source of essential oils is lime peel, which is often discarded and goes unused. The distillation method utilizes microwaves, offering an alternative to conventional distillation techniques and resulting in enhanced effectiveness and efficiency. The Microwave Assisted Hydrodistillation (MAHD) method proves to be more energy-efficient, environmentally friendly, rapid, safe, and cost-effective. This study aims to assess the impact of the MAHD method on the quantity and quality of essential oils extracted from lime peels. Laboratory tests are conducted in accordance with Indonesian national standards. The overarching objective is to establish a process that transforms discarded lime peels into aromatherapy candles, contributing to respiratory health. The MAHD method is employed with a sample mass to distilled water solvent ratio of 1:1. The resulting essential oil undergoes analysis using the GC-MS method. According to the GC-MS test results, the compound with the highest percentage area is limonene at 98%. This is followed by trans-caryophyllene at 99% with a retention time of 12.422, and beta-selinene at 99% with a retention time of 13.191.

Extraction of Basil Leaves Essential Oil using Microwave Assisted Hydrodistillation Method: Physical Characterization and Antibacterial Activity

<p>Basil oil can be obtained from basil leaves by non-extraction methods, namely Microwave Assisted Hydrodistillation (MAHD). Therefore, this research aims to determine the yield percentage, essential oil composition by GC-MS, physical characteristics, and antibacterial activity of basil essential oil. The highest yield of 0.3076% was obtained at the optimum condition, which included a microwave power of 300 W, a mass-to-volume solvent ratio (F/S) of 0.75 g/mL, a raw material size of ± 1.75 cm, and an extraction time of 90 min. The results of the analysis of variance showed that all process parameters used had a significant effect on the yield obtained. Basil oil exhibited a larger inhibition zone against <em>Escherichia coli</em> bacteria (16.38 mm) which tended to be stronger than <em>Staphylococcus aureus</em> (5.95 mm) and was classified as moderate. The main components contained in the basil oil were E-Citral (46.79%) and Z-Citral (38.17%). The physical characteristic test showed that the basil oil was soluble in 96% ethanol after a ratio of 1:9, with 1 ml of basil oil compared to 9 ml of ethanol. The density of basil oil at 0.961 g/mL also complied with the standard value according to the Essential Oil Association (EOA) of <em>Ocimum basilicum</em> Essential Oil. These results showed revealed that the parameter analyzed using oil yields at operating conditions produced the most optimum yield value.</p>

Extraction of citronella oil from lemongrass (Cymbopogon winterianus) by sequential ultrasonic and microwave-assisted hydro-distillation

The Ultrasonic and Microwave-Assisted Hydro-Distillation (US-MAHD) method is a process combination of ultrasonic-assisted extraction (UAE) and microwave-assisted hydro-distillation (MAHD) carried out sequentially. This method aims to improve the UAE and MAHD methods in extracting citronella oil. This study evaluates the performance of US-MAHD in the extraction of citronella oil from the citronella plant. Extraction is conducted for 90 min at various solvent-plant ratios (v/m) (10:1, 12:1, 14:1), ultrasonic bath temperature (30 °C, 40 °C, 50 °C), and power of microwave oven (150 W, 300 W, 450 W). US-MAHD yields a maximum yield of citronella oil of 1.82 mg/g when extracting lemongrass plant with a combination of ultrasonic bath temperature of 30 °C, a solvent-plant ratio of 10:1, microwave power of 300 W, and time of 90 min. All quality parameters of the oil produced have met ISO 3848:1976 standard. Extraction of citronella oil using the US-MAHD method produces higher yields than the UAE and MAHD methods under the same operating conditions. The yields of citronella oil from the US-MAHD, UAE, and MAHD methods are 1.82, 0.92, and 1.48 mg/g, respectively. SEM analysis of residual lemongrass plant shows more cell wall damage which indicates more oil release from the plant matrix.

Evaluation of Chemical Composition of Vaccaria oxyodontha Boiss Plant Essential Oils and Antioxidant and Antibacterial Effects on Gram-Negative and Gram-Positive Bacteria

Background & Aims: Caryophyllaceae is a large family of about 2200 herbaceous or subshrub species. Vaccaria oxyodontha Boiss is of the family Caryophyllaceae. This plant grows as a weed in agricultural land of sugarcane, wheat, barley, forage, and summer crops such as sugar beet, potato, cotton, and onion. All parts of the V. oxyodontha Boiss plant, especially its root, contain a type of saponin, which shows its medicinal value. According to traditional Iranian medicine, this plant is a blood purifier and has anti-infective, utilized for cough, anti-rheumatism, and anti-inflammatory properties. This study first aimed to investigate the chemical composition of V. oxyodontha Boiss essential oil (EO) and the antioxidant and antibacterial properties of the hydroalcoholic extract of this plant on gram-positive and gram-negative bacteria. Materials and Methods: In this study, EOs were extracted from the aerial parts of V. oxyodontha Boiss using the combination of hydrodistillation and microwave-assisted hydrodistillation methods. Then, the antioxidant properties and antibacterial activity of the extract were evaluated, and the chemical compositions of the EOs of V. oxyodontha Boiss were determined using gas chromatography-mass spectroscopy (GC-MS). The extract’s antioxidant activity was studied by the 2,2-diphenyl-1- picrylhydrazyl-hydrate (DPPH) method. In addition, the plant antimicrobial effects were investigated by the agar disk diffusion method, and minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined as well. Finally, the antibacterial activity of the mentioned plant was compared with the antibiotic discs of gentamicin (10 mg) and vancomycin (30 mg). Results: The major compounds in the EOs were 2-Pentadecanone,6,10,14-trimethyl (10.52%) and 1,2-Benzenedicarboxylic acid (19.27%). Half maximal inhibitory concentration (IC50) of V. oxyodontha Boiss was 0.49 µg/mL, which was higher than that of vitamin C (IC50 value of 0.56 µg/mL). Further, MIC and MBC for the V. oxyodontha Boiss extract against Staphylococcus aureus and Escherichia coli were 62.5 and 125 mg/mL, as well as 31.25 and 62.5 mg/mL, respectively. Conclusion: The results of GC-MS demonstrated that the EO of the V. oxyodontha Boiss plant contains antioxidant and antibacterial compounds. Its antioxidant properties are higher than vitamin C. The highest diameter of the inhibition zone caused by the methanol extract of the V. oxyodontha Boiss plant was against S. aureus and E. coli (23.7±0.29 mm and 15.65±0.33 mm, respectively). Compared with the antibiotics vancomycin, the Vaccaria oxyodontha Boiss represented a stronger inhibitory effect in the inhibition of S. aureus (P<0.05).

Essential Oil from Hibiscus Flowers through Advanced Microwave-Assisted Hydrodistillation and Conventional Hydrodistillation

Due to the increased demand and importance of essential oils in medicinal applications, advanced essential oil extraction techniques have been employed. Both conventional hydrodistillation (HD) and microwave-assisted hydrodistillation (MAHD) were employed to extract the essential oils from the hibiscus flower. Extraction time and solvent polarity were the most critical factors. Scanning electron microscopy (SEM) was used to investigate the surface morphologies of raw powdered hibiscus flowers (not exposed to any pretreatment) and pretreated powdered hibiscus flowers (exposed to methanol absorption for 60 minutes prior to extraction). Extractive chemistry analysis utilizing Fourier transform infrared (FTIR) spectroscopy was performed on the volatile oil obtained by MAHD. Different peaks in the gas chromatography/mass spectrometry (GC/MS) analysis indicated the presence of thirty-seven different compositions. MAHD was more energy efficient, had higher yield production, and was environmentally friendly, reducing HD’s overall carbon footprint by 40%. Oxygenated monoterpene, sesquiterpene, and sesquiterpene hydrocarbons were found in the hibiscus flower’s crude extract. Moreover, the methanolic extract of Hibiscus rosa-sinensis has potent antioxidant properties. A hibiscus flower extract had scavenging activities of 51.2% at 0.2 mg/mL, 0.3% at 0.6 mg/mL, 0.8% at 1.0 mg/mL, and 68.5% at 1.2 mg/mL against DPPH free radicals. Therefore, the MAHD method is well-suited to extracting essential oils from hibiscus flowers, and the resulting oil has the potential to provide significant therapeutic advantages.

Characterization of Essential Oil and Wastewater from Thymus nummularius M. Bieb. and Micromorphological Examination of Glandular Trichomes

This study aimed to determine the volatile profile by GC-MS and antimicrobial activity of the essential oil isolated from Thymus nummularius using the microwave-assisted hydrodistillation method and morphologically characterize the glandular trichomes in leaf samples. Obtained essential oil, as well as wastewater obtained during essential oil isolation, were chemically (polyphenolic compounds, organic acids, total phenolic content, total flavonoid content and antioxidant activity) characterized. As a result of GC-MS analysis of the essential oil, different ratios of essential oil components were identified, predominantly thymol (38.91%), linalool (13.12%) and geraniol (6.51%). The antimicrobial activity results showed that T. nummularius essential oil has a broad-spectrum inhibitory effect against all target microorganisms (bacteria and yeast-like fungi). Screening of 32 polyphenolic compounds and 52 organic acids in the wastewater was performed by LC-MS/MS and the major polyphenolic compound and organic acid were determined as caffeic acid (97316.85 µg/kg) and malic acid (6898.88 mg/kg), respectively. While the total phenolic and flavonoid content of the wastewater were 35.91 mg GA/g and 34.91 mg QE/g, respectively, the antioxidant activity results were obtained using the CUPRAC, CERAC and ABTS tests were 86.28 mg TE/g, 72.85 mg TE/g and 47.88 mg TE/g. These results support that the T. nummularius, an important production area in Turkey, can be used in different industrial areas due to its rich bioactive content. In addition, it can be said that wastewater is also considered a valuable source of bioactive substances.

Fungicidal properties of ginger (Zingiber officinale) essential oils against Phytophthora colocasiae

Recently, plant essential oils (EOs) have attracted special attention in plant disease control and food preservation. Since ancient times, essential oils extracted from plants have exhibited many biological characteristics, especially antimicrobial properties. Recent studies have described the potentials of EOs and derivatives to inhibit the growth and reproduction of microorganisms, mainly in response of overwhelming concerns of consumers about food safety. In the context of returning to nature, with the advancement of science and technology and improved living standards, people have begun to seek solutions for food hygiene without chemical additives. Therefore, biological pesticides and plant-oriented chemicals have received special attention from scientists because they are environmentally friendly and nonhazardous, sustainable, and effective alternatives against many noxious phytopathogens. Present study is intended to appraise the fungicidal properties of ginger EOs to combat leaf blight disease of taro, which threatens global taro production. Farmers often hinge on extremely toxic synthetic fungicides to manage diseases, but the residual effects and resistance of chemicals are unavoidable. The microwave-assisted hydrodistillation method was used for ginger EOs extraction and an FTIR (ATR) spectrometer was used to evaluate their chemical composition and citral was identified as most abundant compound (89.05%) in oil. The pathogen isolated from lesions of diseased taro plants was identified as Phytophthora colocasiae and used as test fungus in the present study. Ginger EO was evaluated in-vitro for antifungal properties against mycelium growth, sporangium production, zoospore germination, leaf, and corm necrosis inhibition. Repeated experiments have shown that the concentration of ginger essential oil (1250 ppm) proved to be the lowest dose to obtain 100% inhibition of fungal growth and spore germination, sporangia formation and leaf necrosis assessment. These results are derived from this fungal species and a hypothesis that involves further research on other plant pathogens to demonstrate the overall potency of essential oils. This study references the easy, economic, and environmental management and control of plant diseases using essential oils and byproducts.

Comparative study of chemical composition, antibacterial and antioxidant activity of essential oils isolated from the seeds of Amomum subulatum by using microwave extraction and hydro-distillation methods

Microwave assisted hydro-distillation (MAHD) and conventional hydro-distillation (HD) techniques were compared in the extraction of essential oils from Amomum subulatum seeds. The time required for MAHD method (70 ​min) is lesser than that for HD method (4 ​h). There is a slight increase in the yield of extracted oil in MAHD method (3.35%) compared to HD (3%). Gas chromatography–mass spectrometry GC-MS results show that MAHD extracted essential oil was wealthier in oxygenated compounds. 1, 8-Cineole was found to be a major compound in case of both the essential oil, followed by α-pinene. In MAHD the percentage of the major oxygenated monoterpene (1, 8- cineol) slightly increases from 88% to 89% as compared to hydrodistillation. Contrarily to this, the percentage of monoterpene hydrocarbon was decreased in MAHD than HD extracted oil. MAHD and HD extracted oils show good antibacterial activities against gram-negative and gram-positive bacteria. MAHD extracted oil shows better antibacterial activity than HD extracted against both gram positive and gram-negative bacteria. 2, 2-diphenyl-1-picrylhydrazyl (DPPH•) radical scavenging antioxidant activities show that MAHD extract has better inhibition percentage than HD extract, and the half-maximal inhibitory concentration IC50 value of MAHD was less than HD extracted oil.

EKSTRAKSI SENYAWA ANTOSIANIN DARI KULIT BUAH NAGA MERAH (Hylocereus polyrhizus) MENGGUNAKAN METODE MICROWAVE ASSISTED HYDRODISTILLATION (MAHD)

One of the problems in Indonesia is the use of synthetic dyes in textiles and food. Synthetic dyes themselves can be replaced by natural dyes that are safer for health. Natural dyes can be produced from the pericarp of red pitaya (Hylocereus polyrhizus). The pericarp of the red pitaya has an anthocyanin content of 186.90 mg/100gram. The taking of anthocyanin compounds is usually done using several types of extraction methods. This study used Microwave-Assisted Hydrodistillation (MAHD) method. This method can utilize microwaves to extract natural material compounds. Extraction is performed using ethanol-water solvent (4:1 ratio), material size of ≤0.25 mm with variations in extract time of 2, 4, and 6 minutes. This research discovered that the optimum conditions were at 4 minutes in the MAHD method with an anthocyanin concentration of 52,184 (mg / 100g).

Microwave-assisted hydrodistillation of essential oil from fennel seeds: Optimization using Plackett–Burman design and response surface methodology

The study aims to optimize the microwave-assisted hydrodistillation (MAHD) of Foeniculum vulgare seed essential oil (FSEO), for the purposes of maximizing efficiency and reducing costs in terms of time and energy. Plackett–Burman design (PBD) was investigated to screen the six different variables affecting FSEO extraction and select the most significant ones. Response Surface Methodology (RSM) was used to evaluate the interactions of the significant parameters and to determine optimal conditions. MAHD and the traditional hydrodistillation (HD) techniques were compared in terms of extraction efficiency, economic and environmental impacts, and chemical composition of the FSEO. The optimum conditions of the studied responses were particle size less than 333.4673 μm, at the irradiation time of 20 min and a microwave power of 305.9282 W with a solid-liquid ratio of 0.1477 g/mL. Gas Chromatography (GC) analysis showed that the FSEO composition in MAHD and HD is similar with slight differences. Therefore, the results show that the microwave-assisted hydrodistillation method is an innovative, economical and environmentally friendly approach to efficiently and safely extract essential oil an economic and green innovative approach to extract efficiently and safely the essential oil (EO).

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

A screw extrusion treatment method successfully applies to the extraction of essential oils from Pinus pumila barks under microwave-assisted hydrodistillation conditions, which effectively promotes the increase of the yield of essential oils. Moreover, some potential factors affecting the yield of essential oils have been systematically analyzed and optimized through single factor screening method and Box-Behnken design, and the optimum operating conditions were liquid-solid ratio 5.82 mL/g, microwave irradiation power 585 W, and microwave irradiation time 30 min. Meanwhile, the satisfactory yield of essential oils was 16.51 ± 0.83 mL/kg in the derived optimum conditions, which was highly consistent with the predicted result (17.14 mL/kg) by the Box-Behnken design model. By comparing the kinetic curves of the separation of essential oils by different methods, the bark after the screw extrusion process can obtain higher yield and separation efficiency of essential oils through the microwave-assisted hydrodistillation method. The antioxidant properties and the yield of the essential oils separated by different methods were compared, and the antioxidant capacity and the yield of the essential oils obtained from the barks that were processed by screw extrusion treatment were significantly better than other treatment methods. By comparing the raw materials obtained by different treatment methods and their residues after essential oil separation, it was confirmed that the screw extrusion treatment method greatly increases the yield of the essential oils. The results show that the introduction of screw extrusion treatment and microwave-assisted hydrodistillation in the separation of essential oil has produced significant changes, which may become a new type of essential oil separation technology and be applied to the market.

The effect of microwave power and feed to solvent ratio on antioxidant activity and volatile compounds profile of crystal seedless guava leaves essential oils extracted using microwave-assisted hydrodistillation

This work utilized by-product of crystal seedless guava leaves due to its cultivation for commercial fruit production persuaded to prune guava trees branches. Essential oil (EO) extracted from plant biomass is a source of natural antioxidants due to the presence of essential components. This study was outlined to explore the potential of antioxidants and identify the chemical composition of EO extracted from crystal seedless guava using Microwave-assisted hydrodistillation (MAHD). The essential oils (EOs) were extracted using various microwave powers and feed to solvent (F/S) ratios. The two independent variables showed significantly affect on IC50 value of EOs, thereby there were several various IC50 values in DPPH free radical scavenging assay from EOs depends on their extraction condition. The best condition resulting in IC50 of EO was as low as 36.23 ± 2.07 µg/mL with a microwave power of 600 W and F/S ratio of 1:7 (w/v). The five major constituents of EO from the best extraction condition were caryophyllene (44.98%), caryophyllene oxide (14.96%), trans-nerolidol (9.16%), humulene (5.10%), and aromandendrene (5.10%). The study concluded that MAHD method possessed significant change in antioxidant activity and volatile compounds of EO extracted from crystal guava leaves.

Common Kilka oil and its primary and secondary oxidative dynamics stabilized by different variants of clove essential oil

The objective of this study was to investigate the properties of clove essential oil extracted by different microwave-assisted methods and to evaluate its effects on the stability of common Kilka oil. Each of these methods was hypothesized to yield a clove essential oil that would have a distinguishable composition and effect when added to common Kilka oil by maintaining its oxidative stability. The oxidation of common Kilka oil was examined by accelerated oxidation using the active oxygen method and Rancimat test. The clove essential oil extracted by microwave-assisted hydrodistillation showed the highest induction period according to the active oxygen method (16.56 h) and the Rancimat induction period (3.64 h) in common Kilka oil and its antioxidant activity was comparable to that of BHT (16.59 h and 4.34 h, respectively) and tocopheryl acetate (16.30 h and 4.02 h, respectively). Furthermore, the microwaveassisted hydrodistillation method resulted in the amount of eugenol that exhibited the highest antioxidant capacity for preserving PUFA in common Kilka oil. Ultimately, clove essential oil can become an efficient natural antioxidant for the oxidative stability of common Kilka oil.

The extraction of rosemary essential oil by microwave-assisted hydrodistillation method

Rosemary (Rosmarinus officinalis L.) has been a significant herb and was used as an antiseptic, astringent, antifungal, antibacterial, antioxidant, etc. This study determined the effect of material-water ratio, material size, distillation time, and power of microwave on the obtained yield of rosemary essential oil extracted by microwave-assisted hydrodistillation method. The results show the optimum extraction condition at 1:1 of feed-water ratio, 380W of distillation power, 25 minutes distillation, and 0.3cm of material size with the optimal extracted yield of 2.7%. The major components are α-pinene (22.277%), verbenole (16.488%), 1,8-cineole (16.256%) and geraniol (5.705%), which would be a potential material for cosmetic and pharmaceutical products caused their activities such as antioxidant, antibacterial, antiseptic, reduce anxiety.

Microwave-assisted hydrodistillation and determines volatile components of essential oils from Calamondin (Citrus microcarpa) shells

Since the industrial economic development, natural compounds have received much attention and study in recent years. Essential oils (EOs) that contain many volatile constituents and aromatic compounds have been around for a long time but are still considered today due to their natural characteristics and unique application. In this study, the leaves of Calamondin (Citrus microcarpa) shells were used to investigate the yield of essential oil extracted by the Microwave-assisted hydrodistillation (MAHD). Calamondin essential oil is determined by the microwave assisted hydrodistillation method and analyzed by GC-MS. Extraction essential oil Calamondin with MAHD in optimal conditions for 45 min, 300W capacity and 1:3 shells/water ratio. The main components of volatile compounds in Calamondin essential oils include limonene (96.039%), β-myrcene (0.953%), 1R-α-pinene (0.266%), sabinene (0.55%), 1,6-cyclodecadiene (1.611%), ϒ-eudesmol (0.207%), β-eudesmol (0.232%), α-eudesmol (0.185%). The oil produced by microwaves assisted hydrodistillation (MAHD) method was found to have higher levels of compounds and significant economic values.

Determination of Volatile Components Extracted via Hydro and Microwave-Assisted Distillation of Thamnobryum alopecurum (Hedw.) Gangulee Grown in Turkey and Comparison of Their Antimicrobial Activities

The present study aimed to evaluate the chemical analysis and antimicrobial effects of the Thamnobryum alopecurum (Hedw.) Gangulee essential oils were obtained by different distillation methods (Clevenger apparatus hydrodistillation (HD) and microwave-assisted hydrodistillation (MD)). In this study obtained volatile oils were analyzed by gas chromatography-mass spectrometry which revealed the presence of forty-five compounds present in the essential oil obtained by HD method representing 99.48 % of the total identified compounds and thirty-four compounds were identified in the essential oil extracted by MD method representing 95.39 % of the total identified compounds. 3-octanone was the major constituent of the essential oils extracted by both HD (14.28 %) and MD (20.07 %). Terpenes were the major constituents in the essential oil extra-cted by both methods (54.41 % in HD and 52.21 % in MD) followed by oxygenated terpenoids (17.16 % in HD and 14.94 % in MD). The other major compounds of the essential oil in HD was limonene (9.65 %) followed by β-pinene (9.13 %), cuparene (6.04 %), gymnomitrone (5.72 %) and 4-epi-abietal (5.59 %). While in MD essential oil the other major compounds were β-pinene (12.20 %) followed by limonene (8.56 %), α-pinene (9.01 %), cupa-rene (6.44 %), abietadiene (5.97 %). The antimicrobial effects of the essential oils were determined tested quantitatively in respective broth media by using double microdilution and the minimal inhibition concentration (MIC) values (μg/mL). The isolated essential oils of T. alopecurum showed effective antimicrobial activities against Escherichia coli, Yersinia pseudotuberculosis, Staphylococcus aureus, Enterococcus faecalis, Bacillus cereus, Mycobacterium smegmatis and Candida albicans. However, no activity was not observed against Pseudomonas aeruginosa. The hydrodistillation method was found to be more effective than the microwave method in iden-tifying the chemical composition of the structure of T. alopecurum essential oil. While for antimicrobial study MD method was found to be more effective in terms of antimicrobial effect. The T. alopecurum thus is a potential source of an antimicrobial agent with a wide range of chemical compounds that could be responsible for their activity.

Microwave-assisted hydrodistillation extraction of essential oil from coriander seeds and evaluation of their composition, antioxidant and antimicrobial activity

Coriander seeds essential oil is used in food preparation, perfume, cosmetics and pharmaceuticals. In this study, extraction of essential oil from coriander seeds was done by hydrodistillation (HD) and microwave assisted hydrodistillation (MAHD) methods. Chemical composition, total phenol contents, antimicrobial and antioxidant properties of essential oils were measured and the results were compared between HD and MAHD methods. Scanning electron microscopy (SEM) results showed that the essential oils had inhibitory effect on the bacterial membrane and cell wall. Results showed that total phenol contents and antioxidant activity increased under heat and microwave conditions. Coriander seeds essential oil had a very strong effect on Candida albicans. Gram-positive bacteria were more sensitive to the essential oil of coriander seeds than Gram-negative bacteria. The essential oil extracted by MAHD showed better antimicrobial activity, higher phenols yield and antioxidant activity. According to the results of GC-MS, linalool was the most common constituent of both essential oils.

Essential oils from sugarcane molasses: Chemical composition, optimization of microwave-assisted hydrodistillation by response surface methodology and evaluation of its antioxidant and antibacterial activities

Essential oils have attracted growing attention in the medicine field due to the significant bioactivities. The purpose of present study was devoted to optimizing the microwave-assisted hydrodistillation (MAHD) of sugarcane molasses essential oils (SMEO), compared with chemical components and extraction efficiency of SMEO using MAHD and hydrodistillation (HD) methods, and evaluating antioxidant and antibacterial activities of SMEO extracted by MAHD and HD methods. In this study, microwave-assisted hydrodistillation (MAHD) was first developed to extract SMEO, and MAHD was optimized through single-factor test and response surface methodology (RSM). The optimal processing conditions of SMEO were 60 min of extraction time, 500 W of power, and 1.95 mL/mL of ratio of liquid to solid, and the yield of SMEO was 0.0788 ± 0.002 % (v/v). Compared with yield of SMEO, The MAHD method was more efficient than hydrodistillation (HD) method. Moreover, chemical compositions of SMEO using MAHD and HD methods were identified and compared by gas chromatography-mass spectrometry (GC–MS). Principal chemical components were found in SMEO using MAHD and HD methods, but it was in different content. The antioxidant activity of SMEO was determined by 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assays, and SMEO using MAHD method showed a better antioxidant activity than SMEO using HD method. The antibacterial activity of SMEO were evaluated by determining the diameters of inhibition, the minimum inhibitory concentration (MIC), and the minimum bactericidal concentration (MBC), and the result exhibited that the antibacterial activity of SMEO using MAHD method was higher than SMEO using HD method. The results of scanning electron microscopy (SEM) exhibited that the SMEO using MAHD method changed microstructure of Escherichia coli and Sthaphylococcus aureus. Therefore, the MAHD technology significantly improved the yield of SMEO, and the biological activity results showed a promising alternative and provided a foundation for application of SMEO obtained by MAHD method in food, pharmaceutical, and sanitizers industries.

Optimization and Characterization of Microwave-Assisted Hydro-Distillation Extraction of Essential Oils from Cinnamomum camphora Leaf and Recovery of Polyphenols from Extract Fluid.

In this study, the efficiency of microwave-assisted hydro-distillation (MAHD) to extract essential oil from Cinnamomum camphora leaf, and the recovery of polyphenols from extract fluid were investigated. The effects of microwave power, liquid-to-material ratio, and extraction time on the extraction efficiency were studied by a single factor test as well as the response surface methodology (RSM) based on the central composite design method. The optimal extraction conditions were a microwave power of 786.27 W, liquid-to-material ratio of 7.47:1 mL/g, and extraction time of 35.57 min. The yield of essential oil was 3.26 ± 0.05% (w/w), and the recovery of polyphenols was 4.97 ± 0.02 mg gallic acid equivalent/g dry weight under the optimal conditions. Furthermore, the comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry (GC×GC-TOFMS) was used to characterize the essential oils of fresh and fallen leaves, and 159 individual compounds were tentatively identified, accounting for more than 89.68 and 87.88% of the total contents, respectively. The main ingredients include sabinene, l-β-pinene, β-myrcene, α-terpineol, 3-heptanone, and β-thujene, as well as δ-terpineol and 3-heptanone, which were first identified in C. camphora essential oil. In conclusion, the MAHD method could extract essential oil from C. camphora with high efficiency, and the polyphenols could be obtained from the extract fluid at the same time, improving the utilization of C. camphora leaf.