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Microwave-assisted Extraction (microwave-assisted + extraction)
Selected AbstractsMICROWAVE-ASSISTED EXTRACTION OF CAPSAICINOIDS FROM CAPSICUM FRUITJOURNAL OF FOOD BIOCHEMISTRY, Issue 2 2004OPAL J. WILLIAMS The applicability of microwave irradiation to assist the extraction of capsaicinoids from capsicum fruit was investigated. The procedure involved irradiation of 2 g samples in a closed-vessel followed by gas chromatography of capsaicinoid derivatives. The optimum conditions for extraction were determined to be acetone at 30% power for 7 min irrespective of ground or whole tissue. The yield of the compounds extracted was significantly greater (P < 0.05) using microwave-assisted extraction (MAE) compared to traditional reflux and shaken flask methods. A single extraction step was efficient in recovering approximately 95% of the total capsaicinoid fraction in 15 min compared with 2 h for the reflux and 24 h for the shaken flask methods. Due to the considerable savings in time and energy as well as reliability, this technique is suitable for fast extraction of capsaicinoids from large samples. [source] Microwave-assisted extraction and fingerprint studies of Schisandra chinensis (Turcz.) by high performance liquid chromatography and gas chromatographyJOURNAL OF SEPARATION SCIENCE, JSS, Issue 1 2007Min Zhu Abstract In order to choose an appropriate extraction method, samples of Schisandra chinensis (Turcz.) Baill were extracted by different methods and it was found that microwave-assisted extraction gave the best results. The contents of schisandrin, schisantherin, deoxyschizandrin, and r-schizandrin of 10 samples collected from different regions in China were determined by HPLC. The chromatograms of ten samples were used to establish the fingerprints of Schisandra chinensis (Turcz.) Baill and two methods based on HPLC and GC were applied to them simultaneously. The fingerprints consisted of 18 common peaks obtained by HPLC and 17 common peaks obtained by GC, which showed good stability and repeatability with RSD less than 3% for retention time. The fingerprints are suitable for identifying and differentiating samples by geographical origin and can be used for quality control. [source] Microwave-assisted extraction of total bioactive saponin fraction from Gymnema sylvestre with reference to gymnemagenin: a potential biomarkerPHYTOCHEMICAL ANALYSIS, Issue 6 2009Vivekananda Mandal Abstract Objective , To develop a fast and ecofriendly microwave assisted extraction (MAE) technique for the effective and exhaustive extraction of gymnemagenin as an indicative biomarker for the quality control of Gymnema sylvestre. Methodology , Several extraction parameters such as microwave power, extraction time, solvent composition, pre-leaching time, loading ratio and extraction cycle were studied for the determination of the optimum extraction condition. Scanning electron micrographs were obtained to elucidate the mechanism of extraction Results , The final optimum extraction conditions as obtained from the study were: 40% microwave power, 6,min irradiation time, 85% v/v methanol as the extraction solvent, 15,min pre-leaching time and 25,:,1 (mL/g) as the solvent-to-material loading ratio. The proposed extraction technique produced a maximum yield of 4.3% w/w gymnemagenin in 6,min which was 1.3, 2.5 and 1.95 times more efficient than 6,h of heat reflux, 24,h of maceration and stirring extraction, respectively. A synergistic heat and mass transfer theory was also proposed to support the extraction mechanism Conclusion , Comparison with conventional extraction methods revealed that MAE could save considerable amounts of time and energy, whilst the reduction of volume of organic solvent consumed provides an ecofriendly feature. Copyright © 2009 John Wiley & Sons, Ltd. [source] Microwave-assisted extraction of the main phenolic compounds in flaxseedPHYTOCHEMICAL ANALYSIS, Issue 4 2007Vickram Beejmohun Abstract A microwave-assisted extraction (MAE) method has been applied for the first time to the extraction of the main lignan, secoisolariciresinol diglucoside (SDG), and the two most concentrated hydroxycinnamic acid glucosides in flaxseed. The effects of microwave power, extraction time and alkaline treatment were investigated. It was shown that a 3 min MAE resulted in an SDG content of 16.1 ± 0.4 mg/g, a p -coumaric acid glucoside content of 3.7 ± 0.2 mg/g and a ferulic acid glucoside content of 4.1 ± 0.2 mg/g. These values were compared with those obtained using conventional extraction methods and the results demonstrated that MAE was more effective in terms of both yield and time consumption. Copyright © 2007 John Wiley & Sons, Ltd. [source] Study of the mechanism of microwave-assisted extraction of Mahonia bealei (Fort.) leaves and Chrysanthemum morifolium (Ramat.) petalsFLAVOUR AND FRAGRANCE JOURNAL, Issue 3 2004Shan Gao Abstract A study of microwave-assisted extraction (MAE) for berberine in Mahonia bealei (Fort.) was carried out with batch equipment, in order to investigate the mechanism of the extraction related to structural changes in the glands. The extracts were analysed by ultraviolet-visible spectrophotometry at 347 nm. The parameters investigated were solvent types, the intensity of microwave energy and the process ratio (g/ml) of materials to solvent volume. The microwave-assisted extraction of different moisture content of materials was developed and optimized by means of three-factor and three-level orthogonal designs. Electron and optical micrographs of M. bealei (Fort.) leaves and Chrysanthemum morifolium (Ramat.) petals showed that the mechanism of the extractions was related to structural changes in the plant cells. Copyright © 2004 John Wiley & Sons, Ltd. [source] The optimization of microwave-assisted extraction of decursin from Angelica gigas Nakai rootINTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 7 2006Gee-Dong Lee Summary Response surface methodology was used to display the characteristics of microwave-assisted extraction (MAE) of soluble solids and decursin from Angelica gigas Nakai root, thereby allowing MAE conditions to be optimized. These included ethanol concentration, microwave power and extraction time. The maximal solid yield was predicted to be 44.2% under conditions of 44.9% ethanol concentration, 115.6 W microwave power and 5.8 min extraction time. Decursin content of the extract was estimated to be maximal at 2.52% using 97.7% ethanol, 90.2 W microwave power, and 6.1 min extraction time. The estimated optimal MAE conditions (67% ethanol, 100 W and 6 min) to maximize both components were verified by comparing estimated values with experimental values (42.2% soluble solids, 2.2% decursin), which were higher than those (35.8% solids, 2.0% decursin) obtained by conventional reflux extraction (60% ethanol, 95 °C and 6 h). [source] Determination of main taxoids in Taxus species by microwave-assisted extraction combined with LC-MS/MS analysisJOURNAL OF SEPARATION SCIENCE, JSS, Issue 2 2009Hao Luo Abstract A method based on microwave-assisted extraction (MAE) has been developed for the determination of paclitaxel and five related taxoids, namely 10-deacetylbaccatin III (10-DAB III), cephalomannine, 10-deacetylpaclitaxel (10-DAT), 7-xyl-10- deacetylpaclitaxel (7-xyl-10-DAT), and 7-epi-10-deacetylpaclitaxel (7-epi-10-DAT) in Taxus species in this study. The influential parameters of the MAE procedure were optimized, and the optimal conditions were as follows: extraction solvent 80% ethanol solution, solid/liquid ratio 1:10 (g/mL), temperature 50°C, and three extraction cycles, each cycle 10 min. The method validation for LC-MS/MS analysis was performed. The LOD and LOQ were 3.16,9.20 and 12.20,30.45 ng/mL, respectively. Repeatability and reproducibility for the six taxiods with RSD ranged from 2.78 to 3.85% and from 5.26 to 6.60%. The recoveries of the method for the six taxoids were 92.6,105.6%. The developed MAE-LC-MS/MS method was also successfully applied to determine the contents of six taxoids in different Taxus species. [source] Application of water as a solvent in microwave-assisted extraction for analysis of PCBs and CBzs in fly ashJOURNAL OF SEPARATION SCIENCE, JSS, Issue 6 2005Yifei Sun Abstract Polychlorinated biphenyls (PCBs) and chlorobenzenes (CBzs) are two classes of dioxin precursors formed in municipal solid waste incinerators (MSWIs); they produce negative health effects similar to those of dioxins. Reducing the analytical time required for determining the concentrations of these compounds in MSWIs is important for quickly evaluating their importance and assessing associated health risks. In the present study, water is used as a safe and environmentally friendly solvent in microwave-assisted extraction (MAE) for PCB and CBz analyses. MAE is compared with traditional Soxhlet extraction (SE) to determine the extraction efficiencies. The evaluation of extraction efficiencies shows that MAE has a high extraction efficiency compared with that of SE when water content is lower than 60%. Furthermore, the extraction time and organic solvent consumption are reduced with MAE compared with SE. [source] Microwave-assisted extraction of the main phenolic compounds in flaxseedPHYTOCHEMICAL ANALYSIS, Issue 4 2007Vickram Beejmohun Abstract A microwave-assisted extraction (MAE) method has been applied for the first time to the extraction of the main lignan, secoisolariciresinol diglucoside (SDG), and the two most concentrated hydroxycinnamic acid glucosides in flaxseed. The effects of microwave power, extraction time and alkaline treatment were investigated. It was shown that a 3 min MAE resulted in an SDG content of 16.1 ± 0.4 mg/g, a p -coumaric acid glucoside content of 3.7 ± 0.2 mg/g and a ferulic acid glucoside content of 4.1 ± 0.2 mg/g. These values were compared with those obtained using conventional extraction methods and the results demonstrated that MAE was more effective in terms of both yield and time consumption. Copyright © 2007 John Wiley & Sons, Ltd. [source] Application of an efficient strategy based on MAE, HPLC-DAD-MS/MS and HSCCC for the rapid extraction, identification, separation and purification of flavonoids from Fructus Aurantii ImmaturusBIOMEDICAL CHROMATOGRAPHY, Issue 3 2010Chen Wang Abstract This study presents an efficient strategy based on microwave-assisted extraction (MAE), HPLC-DAD-MS/MS and high-speed counter-current chromatography (HSCCC) for the rapid extraction, identification, separation and purification of active components from the traditional Chinese medicine Fructus Aurantii Immaturus. An LC-DAD-MS/MS method was applied for the screening and structural identification of main components in crude extract, and five components were preliminarily identified as neoeriocitrin, narirutin, naringin, hesperidin and neohesperidin according to their UV and mass spectra. An efficient MAE method for the extraction of the three most abundant components (narirutin, naringin and neohesperidin) was optimized by the combination of univariate and multivariate approaches. The crude extract was then separated and purified by HSCCC and a total of 61.6 mg of narirutin, 207.3 mg of naringin and 159.5 mg of neohesperidin at high purities of 98.1, 97.2 and 99.5%, respectively, were obtained from 1.42 g of crude extract. The recoveries of these compounds were 86, 93 and 89%, respectively. Copyright © 2009 John Wiley & Sons, Ltd. [source] | ||||||||||