Conventional Heat Reflux Extraction Research Articles

Microwave-assisted extraction of pectin from jackfruit rags: Optimization, physicochemical properties and antibacterial activities.

While fruit biowastes pose an environmental hazard, they can be utilized as a source of beneficial biopolymers such as pectin. However, conventional extraction techniques require long processing time with low, impure yields, and microwave assisted extraction (MAE) can suffer from these drawbacks. Here, MAE was applied to extract pectin from jackfruit rags and compared with conventional heating reflux extraction (HRE). Response surface methodology was adopted to optimize pectin yield, based on pH (1.0-2.0), solid-liquid ratio (1:20-1:30), time (5-90min), and temperature (60-95°C). Pectin extraction by MAE required lower temperatures (65.99°C) and shorter reaction times (10.56min). Pectin HRE resulted in a product with amorphous structures and rough surfaces, while pectin-MAE was high crystalline with smooth surfaces. Although both pectin samples showed shear-thinning behavior, pectin-MAE exhibited higher antioxidant and antibacterial activities. Therefore, microwave assisted extraction was an efficient method to extract pectin from jackfruit rags.

Ultrasound-assisted extraction (UAE) of antioxidant phenolics from Corchorusolitorius leaves: a response surface optimization

BackgroundBesides fibre production, Corchorusolitorius is considered a nutritional and medicinal plant in traditional medicine. Its leaves possess different antioxidant compounds and display various biological properties. This study optimized the ultrasound-assisted extraction (UAE) parameters like temperature, time, solvent concentration, and liquid–solid ratio for total flavonoids (TFC) and total polyphenols content (TPC) from leaves employing response surface methodology (RSM).ResultsFindings demonstrated that under the optimized conditions, the highest extraction yield of total flavonoids (7.17 mg QE/g DW) and total polyphenol content (13.92 mg GAE/g DW) were recorded with the ethanol concentration 70.92%, temperature 68.06 °C, liquid–solid ratio 48.80 mL/mg, and ultrasound irradiation time 37.20 min. The optimum value of TFC (6.96 mg QE/g DW) and TPC (13.38 mg GAE/g DW) from the experiment of verification of optimized conditions was close to the predicted value and significantly superior to the conventional heat reflux extraction (HRE). LC–MS and HPLC analysis of the optimized extract from UAE demonstrated the existence of six major phenolic compounds, including chlorogenic acid, isoquercetin, hyperoside, adhyperforin, 1,3-di-O-caffeoylquinic acid, and 3,4-di-O-caffeoylquinic acid. Furthermore, the antioxidant test of the UAE leaves extract revealed an excellent 2,2-diphenyl-1-picrylhydrazyl (DPPH•), 2,2-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS+•) and hydroxyl radical scavenging with IC50 values of 226.29, 199.53 and 402.02 µg/mL, respectively, compared to HRE with 336.31 µg/mL, 253.86 µg/mL, 520.08 µg/mL.ConclusionsThe developed optimization method could contribute to the good recovery of natural antioxidants from C. olitorius in the pharmaceuticals and food industries.Graphical

Phenolic Characterization and Bioactivity of Fennel Seed (Foeniculum vulgare Mill.) Extracts Isolated by Microwave-Assisted and Conventional Extraction

The aim of this study was to evaluate the effectiveness of microwave-assisted extraction (MAE) as an environmentally friendly approach compared to conventional heat-reflux extraction (CE) for the isolation of fennel (Foeniculum vulgare Mill.) seed polyphenols and to assess the bioactivity of the obtained extracts. Water, ethanol (30%, v/v) and acetone (30%, v/v) were used as extraction solvents, and the extraction was carried out varying the temperature (40, 60 and 80 °C), irradiation time (5 and 10 min) and microwave power (300 and 600 W). According to the total phenolic content (TPC), 30% acetone at 80 °C after 5 min of irradiation at 300 W proved to be the optimal MAE conditions for obtaining the highest yield of polyphenols. The phenolic profile of both extracts comprised 21 compounds, with cinnamic acids and flavonols being the most abundant. When compared to CE, the MAE extract showed a lower amount of TPC as well as the sum of all identified individual phenols, although both extracts showed similar antioxidant capacity. The antimicrobial activity of the extract with the highest phenolic content was weak, showing inhibitory activity only against Pseudomonas fragi, Shewanella putrefaciens and Campylobacter jejuni strains, while Gram-positive bacteria and yeasts were not sensitive to the extract.

Microwave-Assisted Extraction of Anticancer Flavonoid, 2',4'-Dihydroxy-6'-methoxy-3',5'-dimethyl Chalcone (DMC), Rich Extract from Syzygium nervosum Fruits.

2′,4′-Dihydroxy-6′-methoxy-3′,5′-dimethyl chalcone (DMC) is a biological flavonoid that is present in the fruits of Syzygium nervosum (Ma-Kiang in Thai). Microwave-assisted extraction (MAE), which utilizes microwave radiation to heat the extraction solvent quickly and effectively, was used to recover DMC-rich extract from Syzygium nervosum fruit. To determine the DMC content, a highly accurate and precise HPLC technique was developed. The influences of MAE conditions, including the solid–liquid ratio, microwave power, and microwave duration on the content of DMC, were sequentially employed by a single factor investigation and response surface methodology (RSM) exploratory design. The predicted quadratic models were fitted due to their highly significant (p < 0.0001) and excellent determination coefficient (R2 = 0.9944). The optimal conditions for producing DMC-rich extract were a ratio of sample to solvent of 1:35 g/mL, a microwave power of 350 W, and a microwave time of 38 min. Under the optimal MAE setting, the DMC content reached 1409 ± 24 µg/g dry sample, which was greater than that of the conventional heat reflux extraction (HRE) (1337 ± 37 µg/g dry sample) and maceration (1225 ± 81 µg/g dry sample). The DMC-rich extract obtained from MAE showed stronger anticancer activities against A549 (human lung cancer cells) and HepG2 (human liver cancer cells) than the individual DMC substance, which makes MAE an effective method for extracting essential phytochemicals from plants in the nature.

Polyphenolic Characterization and Antioxidant Capacity of Laurus nobilis L. Leaf Extracts Obtained by Green and Conventional Extraction Techniques

Laurus nobilis L. is an evergreen Mediterranean shrub whose leaves have been known for various health-promoting effects mainly attributed to polyphenols. Microwave- (MAE) and ultrasound-assisted extraction (UAE) are green extraction techniques that enable effective isolation of polyphenols from plant material. Therefore, the aim of this research was to optimize the extraction conditions of MAE (ethanol percentage, temperature, extraction time, microwave power) and UAE (ethanol percentage, extraction time, amplitude) of polyphenols from Laurus nobilis L. leaves and to assess their polyphenolic profile by ultra performance liquid chromatography- tandem mass spectrometry (UPLC-MS/MS) and antioxidant capacity by oxygen radical absorbance capacity (ORAC) assay. Optimal MAE conditions were 50% ethanol, 80 °C, 10 min and 400 W. Optimal UAE conditions were 70% ethanol, 10 min and 50% amplitude. Spectrophotometric analysis showed the highest total phenolic content in the extracts was obtained by MAE, compared to conventional heat-reflux extraction (CRE) and UAE. The polyphenolic profile of all obtained extracts included 29 compounds, with kaempferol and quercetin glycosides being the most abundant. UPLC-MS/MS showed the highest total phenolic content in the extracts obtained by CRE. ORAC assay showed the highest antioxidant capacity in extracts obtained by CRE, which is in agreement with the polyphenolic profile determined by UPLC-MS/MS.

Phenolic Profile, Antioxidant Capacity and Antimicrobial Activity of Nettle Leaves Extracts Obtained by Advanced Extraction Techniques.

Nettle is a widely known plant whose high biological activity and beneficial medicinal effects are attributed to various bioactive compounds, among which polyphenols play an important role. In order to isolate polyphenols and preserve their properties, advanced extraction techniques have been applied to overcome the drawbacks of conventional ones. Therefore, microwave-assisted extraction (MAE) has been optimized for the isolation of nettle leaves polyphenols and it was compared to pressurized liquid extraction (PLE) and conventional heat-reflux extraction (CE). The obtained extracts were analyzed for their individual phenolic profile by UPLC MS2 and for their antioxidant capacity by ORAC assay. MAE proved to be the more specific technique for the isolation of individual phenolic compounds, while PLE produced extracts with higher amount of total phenols and higher antioxidant capacity. Both techniques were more effective compared to CE. PLE nettle extract showed antimicrobial activity against bacteria, especially against Gram-negative Pseudomonas fragi ATCC 4973 and Campylobacter jejuni NCTC 11168 strains. This suggests that PLE is suitable for obtaining a nettle extract with antioxidant and antimicrobial potential, which as such has great potential for use as a value-added ingredient in the food and pharmaceutical industry.

Comparison of Different Extraction Methods for the Recovery of Olive Leaves Polyphenols

In the present study, advanced extraction techniques, microwave (MAE), ultrasound (UAE), and high pressure (HPAE)-assisted extraction, were applied to improve extraction efficiency of olive (Olea europaea L.) leaves polyphenols. The effect of sample mass (1.5 and 3 g), MAE—time (2, 8.5, and 15 min) and temperature (45 and 80 °C), UAE—time (7, 14, and 21 min) and amplitude (50 and 100%) and HPAE—time (1, 5.5, and 10 min) and pressure (300 and 500 MPa) on the concentration of each analyzed polyphenol compound was examined. Identified polyphenols were oleuropein, hydroxytyrosol, chlorogenic acid, caffeic acid, verbascoside, and rutin. All three advanced extraction techniques yielded higher content of total polyphenols when compared to the conventional heat-reflux extraction (CE) along with a significant reduction of extraction time from 60 (CE) to 2, 21, and 5.5 min in MAE, UAE, and HPAE, respectively. The most intensive values of tested parameters in each technique were the ones that promoted cell wall disruption, e.g., temperature of 80 °C in MAE, 100% amplitude in UAE and 500 MPa in HPAE. MAE and UAE were more efficient in total polyphenols’ recovery than HPAE.

Kinetic Study on Solid-Liquid Extraction of Condensed Tannins from Rosa Canina Branches and Stems

The goal of this study was to point out the effect of parameters (solvent, solid to solvent ratio and extraction time) on the extraction of condensed tannins from Rosa canina feedstock, using conventional methods such as room temperature extraction (RTE) and heat reflux extraction (HRE). Moreover, the extraction kinetics behaviour for HRE has been extensively studied in order to foreshadow a scale up process. The second order rate model was applied to estimate the extraction kinetics of a conventional heat reflux extraction (HRE) at different solid to liquid ratios, concentrations of solvent extraction times. Results showed that the second order rate model was the rate-governing step of the extraction process, and the predicted and experimental data fits very well.

Enrichment in Antioxidant Flavonoids of Stamen Extracts from Nymphaea lotus L. Using Ultrasonic-Assisted Extraction and Macroporous Resin Adsorption.

Nymphaea lotus L. is the medicinal plant that has long been used for food, cosmetics and traditional medicines in Africa and Asia since ancient times. Its flavonoids and other interesting phytochemical compounds from rhizome, leaf and the whole flowers have been reported in the previous published research. However, stamens, which are essential for reproductive functions, may also represent new alternative sources of potential antioxidant flavonoids, as investigated in this study. The innovative green chemistry methods, i.e., ultrasound-assisted extraction (UAE) as well as a macroporous resin (MPR) purification procedure, were employed in this current research. Using a full factorial design coupled to three-dimensional (3D) surface plot methodology, the influence of three variables, namely aqEtOH concentration (ranging from 50 to 100% (v/v), US frequency (ranging from 0 (no US applied) to 45 kHz), and the extraction duration (ranging from 20 to 60 min), were evaluated. Five MPRs with different surface areas, average pore diameters, matrix types and polarities were also investigated for the purification of total flavonoids. The optimal UAE condition is 90% (v/v) aqEtOH with 34.65 khz ultrasonic frequency and 46 min of extraction duration. Compared with the conventional heat reflux extraction (HRE) method, a significant 1.35-fold increase in total flavonoids content was obtained using optimized UAE conditions (169.64 for HRE vs. 235.45 mg/g dry weight for UAE), causing a 2.80-fold increase when this UAE associated with MPR purification (475.42 mg/g dry weight). In vitro cell free antioxidant activity of N. lotus stamen extracts and in cellulo antioxidant investigation using yeast model showed the same trend, indicating that the best antioxidant flavonoid can be found in UAE coupled with MPR purification. Moreover, in the yeast model, the expression of key antioxidant genes such as SIR2 and SOD2 were expressed at the highest level in yeast cells treated with the extract from UAE together with MPR purification. Consequently, it can be seen that the UAE combined with MPR purification can help enhance the flavonoid antioxidant potential of the stamens extract from this medicinal species.

A Quick, Green and Simple Ultrasound-Assisted Extraction for the Valorization of Antioxidant Phenolic Acids from Moroccan Almond Cold-Pressed Oil Residues

Almond (Prunus dulcis (Mill.) D.A. Webb) is one of the most important nut crops both in terms of area and production. Over the last few decades, an important part of the beneficial actions for health associated with their consumption was attributed to the phenolic compounds, mainly accumulated in almond skin. Interestingly, after cold-pressed oil extraction, most of these antioxidant phenolic compounds are retained in a skin-enriched by-product, a so-called almond cold-pressed oil residue. In Morocco, the fifth highest ranking producer in the world, this production generates an important part of this valuable byproduct. In the present study, using a multivariate Box–Behnken design, an ultrasound-assisted extraction method of phenolic compounds from Moroccan almond cold-pressed oil residue was developed and validated. Response surface methodology resulted in the optimal extraction conditions: the use of aqueous ethanol 53.0% (v/v) as a green solvent, applying an ultrasound frequency of 27.0 kHz for an extraction duration of 29.4 min. The present ultrasound-assisted extraction allowed substantial gains in terms of extraction efficiency compared to conventional heat reflux extraction. Applied to three different local Beldi genotypes growing at three different experimental sites, the optimal conditions for ultrasound-assisted extraction led to a total phenolic content of 13.86 mg/g dry weight. HPLC analysis revealed that the main phenolic compounds from this valuable byproduct were: chlorogenic acid followed by protocatechuic acid, p-hydroxybenzoic acid, and p-coumaric acid. The accumulation of these phenolic compounds appeared to be more dependent on the genetic background than on the environmental impact here represented by the three experimental culture sites. Both in vitro cell free and cellular antioxidant assays were performed, and revealed the great potential of these extracts. In particular, correlation analysis provided evidence of the prominent roles of chlorogenic acid, protocatechuic acid, and p-hydroxybenzoic acid. To summarize, the validated ultrasound-assisted extraction method presented here is a quick, green, simple and efficient for the possible valorization of antioxidant phenolic compounds from Moroccan almond cold-pressed oil residues, making it possible to generate extracts with attractive antioxidant activities for future nutraceutical and/or cosmetic applications.

Optimization of Ultrasonic-Assisted Extraction of Total Phenolics from Citrus aurantium L. Blossoms and Evaluation of Free Radical Scavenging, Anti-HMG-CoA Reductase Activities.

The objective of this study was to develop an ultrasonic-assisted procedure for the extraction of total phenolics from Citrus aurantium L. blossoms (CAB) and evaluate the free radical scavenging activity and anti-HMG-CoA reductase activity of the total phenolics. In this work, a Box– Behnken design based on single-factor experiments was used to explore the optimum extraction process. Under the optimum conditions (extraction solvent 70.31% ethanol, extraction temperature 61.94 °C, extraction time 51.73 min, and liquid-to-solid ratio 35.63 mL/g), the extraction yield of total phenolics was 95.84 mg gallic acid equivalents (GAE)/g dry matter (DM), which was highly consistent with the theoretical value (96.12 mg GAE/g DM). The higher contents of total phenolics and five main phenolic compounds obtained from the optimized ultrasonic-assisted extraction (UAE) proved its efficiency when compared with conventional heat reflux extraction (HRE). The total phenolic extract showed excellent free radical scavenging properties against 1,1-diphenyl-2-picrylhydrazyl radical (DPPH·), 2,2′-azino-bis-(3-ethylbenzthiazoline-6-sulphonic acid) radical (ABTS+·), hydroxyl radical (·OH) and superoxide anion radical (·O2−), with IC50 values of 197.007, 83.878, 218.643, and 158.885 μg/mL, respectively; the extracts also showed good inhibition of β-hydroxy-β-methylglutaryl-CoA reductase (HMG-CoA reductase) activity, with an IC50 value of 117.165 μg/mL. Total phenolics from CAB could be a potential source of natural free radical scavenger and HMG-CoA reductase inhibitor.

Intensification of phenolic extraction from yellow European plums by use of conventional, microwave-, and ultrasound-assisted extraction

ABSTRACTIn this study, microwave and ultrasound extraction were selected as process intensification tools to intensify the conventional heat reflux extraction process. Process efficiency was evaluated based on total phenolic content (ascorbic acid, neochlorogenic acid, and chlorogenic acid), scavenging ability of 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric (Fe3+) free radicals, and process intensification principles and domains. Highest phenolic content and antioxidant activity were achieved using microwave extraction followed by heat reflux and ultrasound extraction. Microwave extraction was selected via decision matrix as a suitable process intensification approach based on results and its ability to satisfy process intensification principles.

Ultrasonic-assisted extraction of squalene and vitamin E based oil from Zizyphi Spinosae Semen and evaluation of its antioxidant activity

Zizyphi Spinosae Semen (ZSS) is an herbal medicine with a variety of biological activities. In this study, the oil fraction of ZSS was extracted using an ultrasonic assisted extraction (UAE) method and the value of this underutilized byproduct was explored. The effects of operational parameters of the UAE process (extraction temperature, extraction time, liquid-to-solid ration, and ultrasonic power) on the extraction efficiency were evaluated based on the yield of vitamin E and the squalene, two important compounds in ZSS oil with antioxidant bioactivities. A central composite design was used to optimize these operational parameters. The optimized UAE process resulted in a vitamin E yield of 29.58 ± 0.19 mg/100 g ZSS and a squalene yield of 820.49 ± 3.66 µg/100 g ZSS, which were much higher than those obtained through the conventional heating reflux extraction (HRE) (i.e., vitamin E yield of 18.67 mg/100 g ZSS, and squalene yield of 627.25 µg/100 g ZSS). The ZSS oil contained oleic acid and linoleic acid as the main fatty acid. In addition, the UAE-derived ZSS oil exhibited stronger activities of scavenging ABTs, superoxide anions and hydroxyl radicals, compared to the ZSS oil extracted from HRE. Collectively, this work demonstrated that UAE was an effective method to extract ZSS oil with high yield. The ZSS oil can be used as a potential an antioxidant agent in food and pharmaceutical industries.

Ionic liquid-based microwave-assisted extraction of verbascoside from Rehmannia root

Rehmannia root is widely used as drug and functional food in East Asia and verbascoside content is the main quality control index of Rehmannia root because of its pharmacological activities; thus a fast, and environmentally-benign extraction method of verbascoside from Rehmannia root is a much-needed project. In this work, an ionic liquid (IL)-based microwave-assisted method for the extraction of verbascoside from Rehmannia root was proposed and the driving forces underlying the extraction processes were also explored. Several ILs with different cations and anions and the parameters of microwave-assisted extraction (MAE), including extraction time, the IL concentration, liquid-solid ratio, and microwave irradiation power, were investigated. Experimental results indicated that hydrogen bonding and hydrophobicity of ILs, π–π stacking between ILs and verbascoside, and steric hindrance effect were the fundamental parameters affecting the extraction efficiency. The IL, 1-benzyl-3-methylimidazolium chloride ([Bemim]Cl) showed the highest extraction ability, thus it was selected as the optimal solvent. Meanwhile the optimized extraction conditions were 30 g g–1 of liquid-solid ratio, 0.3 mol L–1 of [Bemim]Cl, 210 W of microwave irradiation power, and 10 s of extraction time. Under the optimal extraction conditions, the extraction yields of verbascoside from fresh, dried, and processed Rehmannia roots were 0.92, 0.34, and 0.22 mg g–1, respectively. Compared with conventional heating reflux extraction and Soxhlet extraction, the IL-based MAE was an efficient and rapid method (extraction time was only 10 s) with simple sample preparation.

Difference research of pectins extracted from tobacco waste by heat reflux extraction and microwave-assisted extraction

Abstract Pectin was extracted from tobacco waste using two different extraction methods of conventional heat reflux extraction (HRE) and microwave-assisted extraction (MAE) respectively. The yield of pectin extracted by the two methods were studied rightfully. Then, the differences in the physicochemical properties of the pectins obtained by the two methods mentioned above were investigated. The results showed that, the two methods may result in different pectin structures, and which will further affect the properties of the pectin. Among them, the influence of microwave frequency on the structure and properties of pectin was particularly significant, excessive frequency always leads to a decrease in pectin properties.

Optimized microwave extraction, characterization and antioxidant capacity of biological polysaccharides from Eucommia ulmoides Oliver leaf

Microwave-induced technique was combined with response surface methodology for optimizing the isolation of polysaccharides from Eucommia ulmoides Oliver leaf. The maximum polysaccharides yield of 12.31% was achieved by microwave extraction at 74 °C for 15 min with a solid to liquid ratio of 1:29 g/mL, which agreed with the predicted value and was 2.9-fold higher than that of the conventional heat-reflux extraction method. The dominant bioactive constituent in extracts was chlorogenic acid (1.3–1.9%), followed by geniposidic acid (1.0–1.7%). The polysaccharides from the optimized extraction had a high molecular weight and polydispersity (Mw 38,830 g/mol, Mw/Mn 2.19), as compared to the fraction prepared in the absence of microwave (Mw 12,055 g/mol, Mw/Mn 1.26). Glucose was the dominant sugar component (38.2–39.1%) of heterogeneous polysaccharides which belonged to a structure of β-type acidic heteropolysaccharides with a glucan group and highly branched degree. The polysaccharides showed a higher DPPH radical scavenging index (0.87–1.22) than BHT (0.41) but lower than BHA (3.56), which can act as a favorable antioxidant in functional food.

Ionic-Liquid-Based Infrared-Assisted Extraction (IL-IRAE) Coupled with HPLC–MS: a Green and Convenient Tool for Determination of TCMs

Infrared radiation, one form of electromagnetic wave, has potential value due to its heating effect, but has become a matter of grave concern in recent years. We describe herein ionic-liquid-based infrared-assisted extraction (IL-IRAE) coupled with high-performance liquid chromatography (HPLC)–mass spectrometry (MS) as a green and convenient method for simultaneous determination of three alkaloids in Lycoris radiata, a traditional Chinese medicine (TCM). Extraction parameters including the type and concentration of IL, extraction solvent, liquid/solid ratio, extraction time, and irradiation power were optimized via orthogonal design and analysis of variance (ANOVA). Chromatography–mass spectrometry was performed in positive ion mode on a TSK gel C18 column (150 mm × 4.6 mm id, 5-µm particle size) with less than 5-min separation. Evaluation of the method showed good results with analytical recovery ranging from 100.66 to 103.90 %. The extraction efficiency of IL-IRAE was proved to be increased by 25 % compared with conventional heat reflux extraction (HRE), ultrasound-assisted extraction (UAE), and microwave-assisted extraction (MAE) methods under the operational parameters investigated in the study, indicating that the developed IL-IRAE method is environmentally friendly, simple, low cost, and efficient, offering great promise for quick determination of active compounds in TCMs and natural plants.

Rapid Analysis of Alpinetin and Cardamonin in Alpinia katsumadai Hayata Using Short-End Injection Microemulsion Electrokinetic Capillary Chromatography Combined with Microwave-Assisted Extraction

A rapid and simple short-end injection microemulsion electrokinetic chromatography (MEEKC) method was developed for the routine analysis of alpinetin and cardamonin in Alpinia katsumadai Hayata in combination with microwave-assisted extraction (MAE). The key parameters affecting separation and extraction were investigated and optimized. The optimal MAE was performed at 800 W for 12 min with 100% ethanol as the extraction solvent, which gave a better extraction efficiency and required a significantly shorter time than conventional heat reflux extraction (HRE) and ultrasonic extraction (USE). When this detection system based on ethyl acetate oil-based MEEKC and short-end injection was applied, the analysis was completed in less than 1.5 min. In the method validation, the relative standard deviations of the migration times and peak areas of the two constituents were 0.74, 1.86% for alpinetin and 0.63, 2.05% for cardamonin, respectively. The recoveries ranged from 94.6 to 105.8%. Compared with previously reported methods, the present method offers a dramatic decrease in overall analysis time, and has the further advantages of easy operation and low running costs.

A Microwave-Assisted Simultaneous Distillation and Extraction Method for the Separation of Polysaccharides and Essential Oil from the Leaves of Taxus chinensis Var. mairei

An efficient microwave-assisted simultaneous distillation and extraction (MA-SDE) method has been developed for the separation of polysaccharides and essential oil from Taxus chinensis var. mairei. The key operating parameters for MA-SDE were optimized by single factor and central composite design experiments, and the optimal conditions were found to include a particle size of 60–80 mesh, liquid/solid ratio of 22.5 mL/g, extraction time of 17.5 min, microwave power of 547 W, and dichloromethane was used as the extraction solvent of the essential oil. The yields obtained for polysaccharides and essential oil under the optimized conditions were 6.39% ± 0.12% and 0.27% ± 0.03%, respectively. The MA-SDE method was also compared with conventional heat reflux extraction (HRE) and hydrodistillation extraction (HDE). The MA-SDE method not only allowed for the simultaneous extraction of polysaccharides and essential oil, but also completed the task with a much shorter extraction time of 17.5 min (HRE and HDE required 3 and 6 h, respectively). Furthermore, the MA-SDE method gave increased extraction yields for polysaccharides (1.14-fold higher than HRE) and essential oil (1.23-fold higher than HDE). Based on these results, this MA-SDE method represents a rapid and efficient technique for the simultaneous extraction of polysaccharides and essential oil.

Green extraction of five target phenolic acids from Lonicerae japonicae Flos with deep eutectic solvent

Abstract In this study, a deep eutectic solvent based microwave assisted extraction (DES-MAE) method was developed. This method was used for the extraction of five target phenolic acids, namely chlorogenic acid, caffeic acid, 3,5-dicaffeoylquinic acid, 3,4-dicaffeoylquinic acid, and 4,5-dicaffeoylquinic acid from Lonicerae japonicae Flos. Twelve kinds of aqueous deep eutectic solvents were investigated. The results indicated that deep eutectic solvents (DESs) showed remarkable effects on the extraction efficiency of phenolic acids. In addition, the parameters of DES-MAE, including concentration of water in DES, liquid/solid ratio, extraction temperature, and extraction time were optimized. The proposed approach was evaluated by comparison with the conventional heat-reflux extraction (HRE) and ultrasound assisted extraction (UAE). Finally, the recovery of active compounds from DES was also investigated. Recovery rates of chlorogenic acid, caffeic acid, 3,4-dicaffeoylquinic acid, 3,5-dicaffeoylquinic acid, and 4,5-dicaffeoylquinic acid reached 79.25%, 80.03%, 85.96%, 86.01% and 85.52%, respectively.