Microwave-assisted method for distillation and dual extraction in obtaining essential oil, proanthocyanidins and polysaccharides by one-pot process from Cinnamomi Cortex

Investigating the effects of thermal processing on bitter substances in atemoya (Annona cherimola × Annona squamosa) through sensory-guided separation

Atemoya (Annona cherimola × Annona squamosa) is a specialty crop in Taiwan. Thermal treatment induces bitterness, complicating seasonal production adjustments and surplus reduction. In this research, sensory-guided separation, metabolomics, and orthogonal partial least squares discrimination analysis (OPLS-DA) are used for identifying the bitterness in atemoya which originates from catechins, epicatechin trimers, and proanthocyanidins. Different thermal treatments (65 °C, 75 °C, and 85 °C) revealed that the glucose and fructose contents in atemoya significantly decreased, while total phenols, flavonoids, and tannins significantly increased. The concentration of 5-hydroxymethylfurfural (5-HMF) increased from 23.16 ng/g in untreated samples to 400.71 ng/g (AP-65), 1208.59 ng/g (AP-75), and 2838.51 ng/g (AP-85). However, these levels are below the 5-HMF bitterness threshold of 3780 ng/g. Combining mass spectrometry analysis with sensory evaluation, OPLS-DA revealed that atemoya treated at 65 °C, 75 °C, and 85 °C exhibited significant bitterness, with the main bitter components being proanthocyanidin dimers and trimers.

Phytochemistry, pharmacological effects and mechanism of action of volatile oil from Panax ginseng C.A.Mey: a review

Panax ginseng (P. ginseng), a traditional and highly valued botanical drug, has been used for thousands of years and is known around the world for its uses in food, medicine, and healthcare. The comprehensive study of P. ginseng is crucial for the quality assurance of medicinal materials and optimal resource utilization. Despite being present in trace amounts, P. ginseng volatile oil has a wide range of chemical metabolites with important medicinal potential. The volatile oil has shown promise in defending the cardiovascular system, as well as in terms of its ability of antibacterial, anti-aging, anti-platelet coagulation, anti-inflammatory, support the nervous system nutritionally, and shield it from harm. Due to its low composition and lack of thorough investigation, P. ginseng volatile oil's therapeutic applicability is still restricted although it exhibited many benefits. This review aims to provide insights into the chemical composition, extraction processes, pharmacological effects, and mechanisms of action of P. ginseng volatile oil, and to provide theoretical support and guidelines for future research and clinical application.

Comparison of quantity, quality and antibacterial activity of essential oil Mentha longifolia (L.) L. under different traditional and modern extraction methods

Extraction is the first and most important step in obtaining the effective ingredients of medicinal plants. Mentha longifolia (L.) L. is of considerable economic importance as a natural raw material for the food and pharmaceutical industries. Since the effect of different extraction methods (traditional and modern methods) on the quantity, quality and antimicrobial activity of the essential oil of this plant has not been done simultaneously; the present study was designed for the first time with the aim of identifying the best extraction method in terms of these features. For this purpose, extracting the essential oil of M. longifolia with the methods of hydrodistillation with Clevenger device (HDC), steam distillation with Kaiser device (SDK), simultaneous distillation with a solvent (SDE), hydrodistillation with microwave device (HDM), pretreatment of ultrasonic waves and Clevenger (U+HDC) and supercritical fluid (SF) were performed. Chemical compounds were identified by gas chromatography coupled with mass spectrometer (GC-MS). Antimicrobial activity of essential oils against various clinical microbial strains was evaluated by agar diffusion method and determination of the minimum inhibitory concentration and minimum bactericidal concentration (MIC and MBC). The results showed that the highest and lowest yields of M. longifolia leaf essential oil belonged to HDC (1.6083%) and HDM (0.3416%). The highest number of compounds belonged to SDK essential oil and was equal to 72 compounds (with a relative percentage of 87.13%) and the lowest number of compounds was related to the SF essential oil sample (7 compounds with a relative percentage of 100%). Piperitenone (25.2-41.38%), piperitenone oxide (22.02-0%), pulegone (10.81-0%) and 1,8-cineole (5-35.0%) are the dominant and main components of M. longifolia essential oil were subjected to different extraction methods. Antimicrobial activity results showed that the lowest MIC value belonged to essential oils extracted by HDM, SDK, SDE and U+HDC methods with a value of 1000 μg/mL was observed against Gram-negative bacteria Shigella dysenteriae, which was 5 times weaker than rifampin and 7 times weaker than gentamicin. Therefore, it can be concluded that in terms of efficiency of the HDC method, in terms of the percentage of compounds of the HDM method, and in terms of microbial activity, the SDK, HDM and U+HDC methods performed better.

Effect of microwave (MW)-subcritical extraction on oil recovery, oxidative stability, and lipid types from Katsuwonus pelamis livers

Katsuwonus pelamis is a tuna species mostly sold for canned fillets, its livers were lack of utilization. This study thus investigated an oil production method combining microwave (MW) pretreatment and subcritical dimethyl ether (SDME) in aim to reach improved efficiency and oil quality. The heating characteristics from different MW powers (400, 600, and 800 W) were evaluated, and SEM showed MW having hydrolysis effect on matrix lipoprotein, the fortified recovery rate was also found. Under the MW-SDME condition with 600 W power, 1:5 solid-to-liquid ratio, and 100 min, the recovery reached 93.21% in maximal (SDME ∼50%). To further improve quality, MW powers was noticed affecting lipid types, fatty acid composition, and oxidative stability of produced oils. 1286 lipid types (mostly glyceride and phospholipid-type) were identified, while higher MW lowered the emulsifying phospholipids prompting phase separation. Several oxidation indexes consistently increased with the rising MW power, GC-MS suggested 400 W for higher DHA.

Microwave Encounters Ionic Liquid: Synergistic Mechanism, Synthesis and Emerging Applications

Progress in microwave (MW) energy application technology has stimulated remarkable advances in manufacturing and high-quality applications of ionic liquids (ILs) that are generally used as novel media in chemical engineering. This Review focuses on an emerging technology via the combination of MW energy and the usage of ILs, termed microwave-assisted ionic liquid (MAIL) technology. In comparison to conventional routes that rely on heat transfer through media, the contactless and unique MW heating exploits the electromagnetic wave-ions interactions to deliver energy to IL molecules, accelerating the process of material synthesis, catalytic reactions, and so on. In addition to the inherent advantages of ILs, including outstanding solubility, and well-tuned thermophysical properties, MAIL technology has exhibited great potential in process intensification to meet the requirement of efficient, economic chemical production. Here we start with an introduction to principles of MW heating, highlighting fundamental mechanisms of MW induced process intensification based on ILs. Next, the synergies of MW energy and ILs employed in materials synthesis, as well as their merits, are documented. The emerging applications of MAIL technologies are summarized in the next sections, involving tumor therapy, organic catalysis, separations, and bioconversions. Finally, the current challenges and future opportunities of this emerging technology are discussed.

Differentiating True and False Cinnamon: Exploring Multiple Approaches for Discrimination

This study presents a comprehensive literature review that investigates the distinctions between true and false cinnamon. Given the intricate compositions of essential oils (EOs), various discrimination approaches were explored to ensure quality, safety, and authenticity, thereby establishing consumer confidence. Through the utilization of physical-chemical and instrumental analyses, the purity of EOs was evaluated via qualitative and quantitative assessments, enabling the identification of constituents or compounds within the oils. Consequently, a diverse array of techniques has been documented, encompassing organoleptic, physical, chemical, and instrumental methodologies, such as spectroscopic and chromatographic methods. Electronic noses (e-noses) exhibit significant potential for identifying cinnamon adulteration, presenting a rapid, non-destructive, and cost-effective approach. Leveraging their capability to detect and analyze volatile organic compound (VOC) profiles, e-noses can contribute to ensuring authenticity and quality in the food and fragrance industries. Continued research and development efforts in this domain will assuredly augment the capacities of this promising avenue, which is the utilization of Artificial Intelligence (AI) and Machine Learning (ML) algorithms in conjunction with spectroscopic data to combat cinnamon adulteration.

Phenolic Fraction from Peanut (Arachis hypogaea L.) By-product: Innovative Extraction Techniques and New Encapsulation Trends for Its Valorization

Peanut skin is a by-product rich in bioactive compounds with high nutritional and pharmaceutical values. The phenolic fraction, rich in proanthocyanidins/procyanidins, is a relevant class of bioactive compounds, which has been increasingly applied as functional ingredients for food and pharmaceutical applications and is mostly recovered from peanut skins through low-pressure extraction methods. Therefore, the use of green high-pressure extractions is an interesting alternative to value this peanut by-product. This review addresses the benefits of the phenolic fraction recovered from peanut skin, with a focus on proanthocyanin/procyanidin compounds, and discusses the improvement of their activity, bioavailability, and protection, by methods such as encapsulation. Different applications for the proanthocyanidins, in the food and pharmaceutical industries, are also explored. Additionally, high-pressure green extraction methods, combined with micro/nanoencapsulation, using wall material derived from peanut industrial processing, may represent a promising biorefinery strategy to improve the bioavailability of proanthocyanidins recovered from underutilized peanut skins.

Facile acid fermentation extraction of silkworm pupae oil and evaluation of its physical and chemical properties for utilization as edible oil

Considering the increasing demand for edible oil in recent times, their price in the world market is becoming skyrocketing. In this research, we produced cost-effective edible oil from desilked silkworm pupae (Bombyx mori) applying a facile acid fermentation process, for the first time. The extraction was performed using two different types of organic acids, 3% of each acetic and citric acid. The yield of the extracted oil was 3.52 ± 0.23% from fresh silkworm pupae. The produced oil was then characterized physically and chemically to know its suitability to be used as edible oil. The oil was found with a low peroxide and acid value of 4.82 meq/kg and 1.35 mg KOH/g oil, respectively, and comprised of different fatty acids, in which palmitic acid (32.04%) and oleic acid (34.62%) were in large portions among the total fatty acids. Additionally, the extracted oil included linoleic, α-linolenic, and dihomo-gamma-linolenic acid which have health benefits. The oil was rich with minerals such as Iron, Sodium, Potassium, Calcium, Magnesium, Zinc, and Phosphorus with a negligible concentration of toxic elements such as Manganese, Cobalt, Nickel, Copper, Lead, Cadmium, Chromium, Arsenic, and Silver, indicating a good nutritive value of the extracted oil. Overall, the outcomes of all the characterizations showed that the extracted oil could be used as good edible oil and the corresponding acid fermentation extraction process has the potential to be used as an effective oil extraction method for silkworm pupae.

New insights into non-extractable phenolic compounds analysis

Most of the studies regarding phenolic compounds (PC) have been focused only on one fraction of PC, named extractable phenolic compounds (EPC). As the name suggests, EPC can be directly extracted from the food matrix by using an appropriate solvent. Otherwise, non-extractable phenolic compounds (NEPC) remain in the food matrix after the conventional extraction, and their analysis depends on a hydrolysis process. NEPC is a relevant fraction of PC that acts in the colon, where they are extensively fermented by the action of the microbiota. To understand the health effects associated with the NEPC intake, it is necessary to know which types of compounds are present and their content in foods. In this review, 182 studies published in the last five years about NEPC in foods were evaluated, focusing on critical points of the NEPC analysis. First, EPC exhaustive extraction should be performed before the hydrolysis processes to avoid overestimation of the NEPC fraction. NEPC hydrolysis by aggressive methods modifies their original structure and makes their complete elucidation difficult. These methods must be optimized considering the research objective, as different conditions may result in different amounts and profiles of compounds. Concerning quantification, the widely used spectrophotometric Folin-Ciocalteu method should be avoided as it leads to overestimation. Liquid chromatography coupled to a diode array detector is the most appropriate technique for this purpose. Although pure standard compounds are unavailable in most cases, standards representative of a PC family can be used, and results can be expressed as equivalent. The best approach for NEPC identification is liquid chromatography coupled to a diode array detector and tandem high-resolution mass spectrometry, which generates information regarding chromatographic behavior, UV-vis absorption, accuracy mass and fragmentation pattern. The identification process should associate manual data handling with the bioinformatics-assisted approach.

Optimization of the Extraction of Proanthocyanidins from Grape Seeds Using Ultrasonication-Assisted Aqueous Ethanol and Evaluation of Anti-Steatosis Activity In Vitro

Conventional extraction methods of proanthocyanidins (PAC) are based on toxic organic solvents, which can raise concerns about the use of extracts in supplemented food and nutraceuticals. Thus, a PAC extraction method was developed for grape seeds (GS) and grape seed powder using food-grade ethanol by optimizing the extraction conditions to generate the maximum yield of PAC. Extraction parameters, % ethanol, solvent: solid (s:s) ratio, sonication time, and temperature were optimized by the central composite design of the response surface method. The yields of PAC under different extraction conditions were quantified by the methylcellulose precipitable tannin assay. The final optimum conditions were 47% ethanol, 10:1 s:s ratio (v:w), 53 min sonication time, and 60 °C extraction temperature. High-performance liquid chromatography analysis revealed the presence of catechin, procyanidin B2, oligomeric and polymeric PAC in the grape seed-proanthocyanidin extracts (GS-PAC). GS-PAC significantly reduced reactive oxygen species and lipid accumulation in the palmitic-acid-induced mouse hepatocytes (AML12) model of steatosis. About 50% of the PAC of the GS was found to be retained in the by-product of wine fermentation. Therefore, the developed ethanol-based extraction method is suitable to produce PAC-rich functional ingredients from grape by-products to be used in supplemented food and nutraceuticals.

Effects of ultrasound and microwave pretreatments on hydrodistillation extraction of essential oils from Kumquat peel

Main objectives of this work were to investigate the influences of ultrasound pretreatment (UP) and microwave pretreatment (MP) on extraction kinetics, chemical composition, and antioxidant activity of Kumquat peel essential oil (EO) obtained by hydrodistillation extraction (HDE). The effects of ultrasound power and processing time, and microwave power and processing time were evaluated. As compared with HDE individually, UP and MP decreased the extraction time, increased the yield and DPPH radical-scavenging activity but did not noticeably affect chemical composition of the EO. For UP and MP, the highest EO yield was obtained when the ultrasonic power and processing time, and microwave power and processing time were 210 W and 30 min, 300 W and 6 min, respectively. In comparison with MP, UP gave a higher yield and DPPH radical-scavenging activity of the EO. Overall, UP and MP are promising techniques for HDE of EO from kumquat peel.

In-situ reactive heat breaking cell wall by SO3 hydration: innovative cell-wall breaking technique to enhance extraction of cinnamaldehyde from cinnamon

Cinnamaldehyde (CA) is one of the major active pharmaceutical ingredient of cinnamon bark. Hydrodistillation (HD) is usually used in CA extraction, however, the extraction yield is lower. The cell wall is a key factor limiting the extraction of essential oils. In-situ reactive heat breaking cell wall (RHB) could destroy the cell wall, which was conducive to the diffusion of CA. The aim of this work was to examine the effect of RHB pretreatment to HD extraction. Response surface methodology (RSM) was used to optimize RHB pretreatment parameters, and Box-Behnken Design (BBD) method was performed to evaluate the effects of different operating parameters. The maximum yield was increased to 3.31 ± 0.11% (w/w) from 2.08 ± 0.042% (w/w) after RSM optimization. Scanning electron microscopic (SEM) analysis showed that RHB destroyed and disrupted the cell wall of cinnamon bark. The GC analysis demonstrated that the purity of cinnamaldehyde was improved and no new components were presented in the extraction product from the cinnamon via RHB pretreatment. In conclusion, RHB is an effective pretreatment method for the CA extraction, and also may be used in the other herbal medicine extraction.

Assessment of bioavailability and mobility of major and trace elements in agricultural soils collected in Port St Johns, Eastern Cape, South Africa using single extraction procedures and pseudo-total digestion

PURPOSE

The aim of this study was to evaluate the applicability of ultrasound assisted single extraction and pseudo-total digestion procedures to investigate the bioavailability and mobility of major and trace elements collected from agricultural soil collected in Mzimvubu farmstead area located in Port St Johns, Eastern Cape Province (South Africa).

MATERIALS AND METHODS

The potential metal availability was assessed using complexing agent (ethylenediaminetetraacetic acid (EDTA)), mild (cacium chloride (CaCl2) and ammonium nitrate (NH4NO3)), deionized water and acidic (CH3COOH) extractants with the assistance of ultrasound to evaluate mobility and bioavailability of metals. The ultrasound radiation was used to assist the single extraction of major and trace metals from agricultural soils as well shortening the extraction time. The pseudo-total metal content in agricultural soils was obtained using pseudo-total digestion employing aqua-regia.

RESULTS AND DISCUSSION

The results obtained using different solvents for single extraction procedures, revealed that higher extraction of Al (256-681 mg kg-1), Fe (172-430 mg kg-1) and Mn (35-136 mg kg-1), was observed compared to other metals. Among the investigated solvents, deionized water, acetic acid and EDTA proved to be the most aggressive extractants. The geo-accumulation index (2-6) and contamination factor (3-6) demonstrated that Fe, Cr, Mn, Co, Cu, Ni, and Zn could pose significant environmental contamination risk.

CONCLUSIONS

Based on the results obtained, it can be concluded that the high levels of some studied metals was due to anthropogenic activities.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s40201-020-00581-x.

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.

Microwave-Assisted Improved Extraction and Purification of Anticancer Nimbolide from Azadirachta indica (Neem) Leaves

Nimbolide, a limonoid present in leaves of the neem tree (Azadirachta indica), is an anticancer compound against a panel of human cancer cell lines. The rapid process of extraction and purification of the nimbolide from the leaves of neem tree through microwave-assisted extraction (MAE) coupled with a chromatographic technique was accomplished. The crude with a maximum content of nimbolide could be recovered from neem leaves through MAE. By using three-factors, three-level Box–Behnken design of response surface methodology (RSM), the optimal conditions for nimbolide extraction (R² = 0.9019) were solid/liquid ratio 1:16 g/mL, microwave power 280 W, and extraction time 22 min. The enriched extract was further purified by a preparative thin-layer chromatography (PTLC), where nimbolide was obtained as 0.0336 g (0.67% yield, purity over 98%) with ethyl acetate/hexane = 4:6 in 3.0 h. Structural elucidation was performed through spectroscopic techniques, including FT-IR, ¹H, and ¹³C-NMR. This method was simple and had a good potential for the purification of bioactive compounds from a natural product.

Microwave-assisted extraction of hempseed oil: studying and comparing of fatty acid composition, antioxidant activity, physiochemical and thermal properties with Soxhlet extraction

This work aimed to investigate the effects of the microwave-assisted extraction (MAE) on the hempseed (Cannabis sativa L.) oil yield, oxidation stability, and antioxidant activity. Power (300, 450, and 600 W) and time (5, 10, and 15 min) were independent variables while oil extraction yield, peroxide value (PV), p-anisidine value (AV), TOTOX value (TV), and DPPH scavenging activity were considered as dependent ones. Optimization was conducted by response surface methodology where the optimum point was 450 W and 7.19 min. In this point, the extraction yield obtained 33.91% w/w and the oil showed acceptable oxidation quality (PV of 2.5 meq/kg, AV of 0.67, and TV of 5.67) and antioxidant activity with the IC₅₀ value of 30.82 mg/mL. The Soxhlet extraction (SE) method was carried out to be compared with MAE. It showed relatively higher oil extraction yield (37.93% w/w) but lower oil oxidation stability with PV of 6.4 meq/kg, AV of 3.69, TV of 16.49, and higher amount of IC₅₀ 32.47 mg/mL which showed lower antioxidant activity. Any significant difference between fatty acid compositions was not observed with the dominant amounts of linoleic acid and α-linolenic acid. Also, the tocopherol contents and thermal properties were studied by HPLC and DSC, respectively. MAE showed higher total tocopherol content (929.67 mg/kg) than SE (832.61 mg/kg) and γ-tocopherol was dominant. Moreover, DSC analysis showed that both profiles (crystallization and melting transitions) are likely influenced mostly by the triglyceride compositions and crystals structure.

Optimization of Microwave-Assisted Extraction Saponins from Sapindus mukorossi Pericarps and an Evaluation of Their Inhibitory Activity on Xanthine Oxidase

A microwave-assisted extraction (MAE) method was applied to separate saponins from Sapindus mukorossi pericarps. The most important factors of the six extraction parameters were selected using Plackett–Burman designs; therefore, the further extraction procedure was optimized using the Box–Behnken designs; meanwhile, the optimum processing parameters and well-pleasing saponins extraction rate were inferred. The final operation conditions were the ethanol concentration of 40%, soaking time of 3 h, particle size of 80–100 meshes, extraction time of 13 min, solvent-solid ratio of 19 mL/g, and microwave power of 425 W. Based on the optimal extraction parameters, the extraction rate of the saponins by means of MAE technique reached 280.55 ± 6.81 mg/g, which exceeds yields acquired using conventional manners. Saponins from S. mukorossi have obvious xanthine oxidase inhibitory properties in vitro compared with allopurinol. The saponins displayed a type of competitive inhibition of xanthine oxidase. In conclusion, a MAE technique in association with a response surface design provides an efficient extraction tactics, which could sufficiently isolate saponins from S. mukorossi pericarps; further, this technique could be applied to the dissociation of other bioactive substances from plant sources. In addition, the saponins may be a promising alternative to conventional medicine to treat gout and other inflammation-associated disorders to mitigate the side effects of traditional drugs.

Sono hydrodistillation for isolation of citronella oil: A symbiotic effect of sonication and hydrodistillation towards energy efficiency and environment friendliness

Environmental benign approach for extraction of essential oil was made. An essential oil rich in citronellol, linalool and citronellal was extracted from the leaves of Cymbopogon winterianus using a clean hybrid extraction technique, sono hydrodistillation. Sono hydrodistillation combines ultrasonic waves along with conventional hydrodistillation process to have symbiotic outcomes in terms of process improvement. Significant process parameters such as size of the plant material, extraction time, power, ultrasound amplitude, pulse interval and solid loading were investigated independently to study the effect on yield of oil and composition of oil. The water residue remained after extraction of volatile oil was analyzed using Folin-Ciocalteu method to determine the total phenolic content (TPC) which would help in assessing the residue as a useful by-product. Substantial reduction in time was observed with the inclusion of ultrasound compared to conventional hydrodistillation. Further, to optimize the extraction conditions, observe interactive effects of various parameters and develop mathematical model, response surface methodology was employed. The maximum yield of oil was found to be 4.118% (w/w) at 21 min extraction time, 5 g solid loading, 250 mL water volume, 500 W heating mantle power, 70% ultrasonic amplitude and 10:50 pulse interval. Total phenolic content was 13.84 mg GAE/g DM. The citronella oil was found to be composed of 27.47% of linalool, 11.52% of citronellal, 34.25% citronellol and 11.15% of elemol. Extraction time, solid loading and pulse interval had the significant influence on the yield of oil and total phenolic contents. Microscopic analysis has assisted in envisaging the probable mechanism indicating the role of sonication for rapid extraction. This novel technique was compared with the conventional hydrodistillation to ascertain the impact towards process intensification. Sono hydrodistillation was found to be a greener and cleaner process as energy consumption has been reduced by 40% while carbon footprint has shrunken by 47%.

Optimization of Vacuum Microwave-Mediated Extraction of Syringoside and Oleuropein from Twigs of Syringa oblata

A vacuum microwave-mediated method was used to extract syringoside and oleuropein from Syringa oblata twigs. The optimal extraction conditions were an ethanol volume fraction of 40%, a liquid-solid ratio of 17 mL/g, 1 h of soaking time, -0.08 MPa of vacuum, a microwave irradiation power of 524 W, and a microwave irradiation time of 8 min. Under optimal parameters, the maximum yields of syringoside (5.92 ± 0.24 mg/g) and oleuropein (4.02 ± 0.18 mg/g) were obtained. The proposed method is more efficient than conventional methods for extracting syringoside and oleuropein from Syringa oblata. Moreover, less energy and time were required. The results implied that vacuum microwave-mediated extraction is a suitable method for the extraction of thermosensitive glycosides such as syringoside and oleuropein.

Fast microwave-assisted sorption of heavy metals on the surface of nanosilica-functionalized-glycine and reduced glutathione

Two eco-friendly nanosorbents have been designed and synthesized via surface crosslinking of nanosilica (N-Si) with glycine (Gly) and reduced glutathione (GSH) to produce (N-Si-Gly) and (N-Si-Glu) using crosslinking reagent and sonochemical reactions, respectively. An investigation was performed to search selectivity of nanosorbents via microwave-assisted removal of Ni(II)/Cu(II)/Cd(II)/Pb(II) to affirm green and fast technique. The microwave-assisted removal values of Ni(II), Cu(II), Cd(II) and Pb(II) were observed at 850, 2100, 3500 and 2150 μmol g^-1, respectively utilizing 10 mg of (N-Si-Glu) and 25.0 s heating, while those corresponded to 750, 1800, 2500 and 1850 μmol g^-1, respectively by using (N-Si-Gly). The microwave-assisted removal processes were more fitted to Freundlich compared to Langmuir isotherm except in case of Pb(II). The high percent removal of Cd(II) and Pb(II) ions exceed 95% from the second run in real wastewater samples indicating the efficiency of N-Si-Glu in the uptake of these metals utilizing microwave-assisted sorption technique.

Optimization of microwave assisted extraction of essential oils from Iranian Rosmarinus officinalis L. using RSM

In this study, the efficiencies of conventional hydro-distillation and novel microwave hydro-distillation methods in extraction of essential oil from Rosemary officinalis leaves have been compared. In order to attain the best yield and also highest quality of the essential oil in the microwave assisted method, the optimal values of operating parameters such as extraction time, microwave irradiation power and water volume to plant mass ratio were investigated using central composite design under response surface methodology. Optimal conditions for obtaining the maximum extraction yield in the microwave assisted method were predicted as follows: extraction time of 85 min, microwave power of 888 W, and water volume to plant mass ratio of 0.5 ml/g. The extraction yield at these predicted conditions was computed as 0.7756%. The qualities of the obtained essential oils under designed experiments were optimized based on total contents of four major compounds (α-pinene, 1,8-cineole, camphor and verbenone) which determined by gas chromatography equipped with mass spectroscopy (GC-MS). The highest essential oil quality (55.87%) was obtained at extraction time of 68 min; microwave irradiation power of 700 W; and water volume to plant mass ratio of zero.

Antioxidant Activities of Extracts from Sarcocarp of Cotoneaster multiflorus

The ethanol-water (7 : 3, v/v) extract of Cotoneaster multiflorus sarcocarp was sequentially fractionated by liquid-liquid partition using n-hexane, diethyl ether, methylene dichloride, and ethyl acetate. The contents of total polyphenols, total flavones, and oligomeric proanthocyanidins in the five parts (including the ethanol-water extract) were determined. In addition, 2,2-diphenyl-1-picrylhydrazyl free radical-scavenging, 2,2-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt radical cation decolorization, reducing power, ferric reducing antioxidant power, and lipid peroxidation inhibition assays were conducted to test the antioxidant activities of Sample 1 (the ethanol-water fraction) and Sample 2 (the ethyl acetate fraction) in vitro. In the above five assays, Sample 2 showed greater antioxidant capacities than Sample 1. Furthermore, Sample 2 was better able to protect low-density lipoproteins from oxidation in a dose-dependent manner. The test results show that C. multiflorus sarcocarp, especially the ethyl acetate-soluble fraction, may be a potential source of natural antioxidants.

A modified approach for isolation of essential oil from fruit of Amorpha fruticosa Linn using microwave-assisted hydrodistillation concatenated liquid-liquid extraction

In this work, a modified technique was developed to separate essential oil from the fruit of Amorpha fruticosa using microwave-assisted hydrodistillation concatenated liquid-liquid extraction (MHD-LLE). The new apparatus consists of two series-wound separation columns for separating essential oil, one is the conventional oil-water separation column, and the other is the extraction column of components from hydrosol using an organic solvent. Therefore, the apparatus can simultaneously collect the essential oil separated on the top of hydrosol and the components extracted from hydrosol using an organic solvent. Based on the yield of essential oil in the first and second separation columns, the effects of parameters were investigated by single factor experiments and Box-Behnken design. Under the optimum conditions (2mL ethyl ether as the extraction solvent in the second separation column, 12mL/g liquid-solid ratio, 4.0min homogenate time, 35min microwave irradiation time and 540W microwave irradiation power), satisfactory yields for the essential oil in the first separation column (10.31±0.33g/kg) and second separation column (0.82±0.03g/kg) were obtained. Compared with traditional methods, the developed method gave a higher yield of essential oil in a shorter time. In addition, GC-MS analysis of the essential oil indicated significant differences of the relative contents of individual volatile components in the essential oils obtained in the two separation columns. Therefore, the MHD-LLE technique developed here is a good alternative for the isolation of essential oil from A. fruticosa fruit as well as other herbs.

Strategies for the extraction and analysis of non-extractable polyphenols from plants

The majority of studies based on phenolic compounds from plants are focused on the extractable fraction derived from an aqueous or aqueous-organic extraction. However, an important fraction of polyphenols is ignored due to the fact that they remain retained in the residue of extraction. They are the so-called non-extractable polyphenols (NEPs) which are high molecular weight polymeric polyphenols or individual low molecular weight phenolics associated to macromolecules. The scarce information available about NEPs shows that these compounds possess interesting biological activities. That is why the interest about the study of these compounds has been increasing in the last years. Furthermore, the extraction and characterization of NEPs are considered a challenge because the developed analytical methodologies present some limitations. Thus, the present literature review summarizes current knowledge of NEPs and the different methodologies for the extraction of these compounds, with a particular focus on hydrolysis treatments. Besides, this review provides information on the most recent developments in the purification, separation, identification and quantification of NEPs from plants.

An efficient approach for the extraction of orientin and vitexin from Trollius chinensis flowers using ultrasonic circulating technique

Ultrasonic circulating extraction (UCE) approach was developed for effective extraction of orientin and vitexin from the flowers of Trollius chinensis successfully. In this study, some parameters potentially influencing the yields of orientin and vitexin were systematically investigated and optimized by Plackett-Burman and Box-Behnken design, and the optimum operational conditions obtained were 60% ethanol volume fraction, 1000r/min stirring speed, 30°C temperature, 28min ultrasonic irradiation time, 10mL/g liquid-solid ratio and 738W ultrasonic irradiation power. Satisfactory yields of orientin (6.05±0.19mg/g) and vitexin (0.96±0.03mg/g) were obtained in a relatively shorter extraction time under the derived optimum conditions, compared to other ultrasonic extraction methods and heat extraction methods. The mechanism of UCE procedure was discussed in detail, to illustrate the advantage of UCE in the extraction process. In addition, no degradation of orientin and vitexin and high reproducibility of the developed UCE method were observed under the optimum conditions. The proposed UCE technique with high-capacity and circulation function is a rapid and efficient sample extraction technique, and performs promising in large-scale sample preparation.

Polysaccharides from Traditional Chinese Medicines: Extraction, Purification, Modification, and Biological Activity

Traditional Chinese Medicine (TCM) has been used to treat diseases in China for thousands of years. TCM compositions are complex, using as their various sources plants, animals, fungi, and minerals. Polysaccharides are one of the active and important ingredients of TCMs. Polysaccharides from TCMs exhibit a wide range of biological activities in terms of immunity- modifying, antiviral, anti-inflammatory, anti-oxidative, and anti-tumor properties. With their widespread biological activities, polysaccharides consistently attract scientist's interests, and the studies often concentrate on the extraction, purification, and biological activity of TCM polysaccharides. Currently, numerous studies have shown that the modification of polysaccharides can heighten or change the biological activities, which is a new angle of polysaccharide research. This review highlights the current knowledge of TCM polysaccharides, including their extraction, purification, modification, and biological activity, which will hopefully provide profound insights facilitating further research and development.