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Ethanol Extraction (ethanol + extraction)
Selected AbstractsSUPERCRITICAL CO2/ETHANOL EXTRACTION OF ASTAXANTHIN FROM BLUE CRAB (CALLINECTES SAPIDUS) SHELL WASTEJOURNAL OF FOOD PROCESS ENGINEERING, Issue 2 2001LETICIA FÉLIX-VALENZUELA ABSTRACT Astaxanthin (AX) is the major naturally occurring carotenoid pigment in marine crustaceans and the flesh of salmonids. These organisms are unable to synthesize AX de novo and when farmed commercially, require it in their feed. The high cost of synthetic AX has promoted research into new natural sources of ihe pigment, such as crustacean wastes. In this work, AX from demineralized crab (Callinectes sapidusj shell waste was extracted with a mixture of supercritical C2 and ethanol as a cosolvent. The effect of total solids load, pressure and temperature was assessed by response surface methodology (RSM). Extracted AX was determined by HPLC. The experimental data were fined to a second order model whereby the conditions for maximum extraction yield were defined (, 34 MPa, 45C and solids load of 25 g). Pressure and solids load were the most important factors affecting AX extraction yields. [source] Application of supercritical fluid extraction to regenerate spent Pd-active carbon catalystENVIRONMENTAL PROGRESS & SUSTAINABLE ENERGY, Issue 4 2007Lidia D Abstract Pd-active carbon-type catalysts are used in a wide variety of processes, typical examples of which are liquid-phase hydrogenation reactions. In the case of these catalysts, a loss of their catalytic activity is observed. The aim of the present work was to assess the possibility of regenerating spent Pd/AC catalysts using supercritical fluid extraction. The following Pd/AC catalyst samples were investigated and compared: a commercial 10 wt % Pd catalyst (Aldrich) (denoted by CC), a spent catalyst (SC), SC subjected to supercritical fluid,CO2 extraction (SC/SFE/C), SC subjected to supercritical fluid,CO2,ethanol extraction (SC/SFE/C-Et), and SC subjected to supercritical fluid,ethane,propane extraction (SC/SFE/E-P). The last three catalysts were additionally subjected to heating in a hydrogen atmosphere at 410 K for 3 h. These were denoted by SC/SFE/C/H, SC/SFE/C-Et/H, and SC/SFE/E-P/H, respectively. The spent Pd/AC catalyst (SC) consists of mixed CC samples used in the reduction with hydrogen of various organic compounds. The catalysts CC, SC/SFE/C, SC/SFE/C/H, SC/SFE/C-Et/H, and SC/SFE/E-P/H were tested in the reduction of octanoylbenzene with hydrogen. The activity of the catalysts was estimated by measuring the reaction time and also the amount of hydrogen used in relation to the theoretical quantity required for the reaction. XPS and XRD methods were used to evaluate the changes occurring in the form of the palladium present on the Pd/AC catalyst surface during the regeneration processes. It was found that supercritical fluid-CO2 extraction followed by heating in a hydrogen atmosphere is the most effective method for regenerating that catalyst. The results of our investigations indicate that regeneration of a spent Pd/AC catalyst, irrespective of the reaction in which it has been used, should be based on the complete removal of byproducts, the purification of the catalyst surface, and the restoration of the original form of the palladium. The procedure proposed in this paper, i.e. SFE (CO2) and heating in H2, fulfils both the conditions mentioned above. © 2007 American Institute of Chemical Engineers Environ Prog, 2007 [source] Beyond six scents: defining a seventh Thymus vulgaris chemotype new to southern France by ethanol extractionFLAVOUR AND FRAGRANCE JOURNAL, Issue 3 2009Ken Keefover-Ring Abstract The concept of plant chemotype has long been useful to describe secondary chemical phenotypes; however, the idea has practical limitations, especially when applied to ecological questions. This work reports the discovery of a new 1,8-cineole chemotype of Thymus vulgaris from a well-studied area in southern France. Multivariate statistical analysis of ethanol-extracted plant terpenes was used to describe this new chemotype and three others found at the site, and the results are used to discuss the chemotype concept. While the total amount of essential oils among these chemotypes showed no difference, the concentration of the main terpene differed significantly, with the 1,8-cineole and cis -sabinene hydrate chemotypes having the lowest amounts of their respective main components, and the linalool chemotype having the highest. The , -terpinyl acetate chemotype had intermediate levels of its main terpene. A factor analysis revealed four factors which explained almost 89% of the total variation in plant essential oils. Each factor represented a separate chemotype, including a cis -sabinene hydrate, linalool, ,- terpinyl acetate and the new 1,8-cineole chemotype. Although the concept of plant chemotype is still valid, better definitions are important when evaluating the influences of a plant's secondary chemistry on other community members. Copyright © 2009 John Wiley & Sons, Ltd. [source] Supercritical carbon dioxide extraction of 2-acetyl-1-pyrroline and volatile components from pandan leavesFLAVOUR AND FRAGRANCE JOURNAL, Issue 3 2004Natta Laohakunjit Abstract The ,avour of pandan (Pandanus amaryllifolius Roxb.) leaves was extracted by supercritical ,uid with CO2 (SC-CO2) under different conditions of pressure, temperature and contact time to determine the yield of 2-acetyl-1-pyrroline (ACPY) and various other components; 14 volatile compounds on the gas chromatogram were identi,ed, and the predominant constituents were ACPY and 3-methyl-2(5H)-furanone. The interaction of different conditions signi,cantly in,uenced the yield of ACPY and various volatile compounds. There is a potential for high yield of ACPY by SC-CO2 at 200 bar, 500 °C and 20 min. The SDE,ether extract was found to have a very small amount of ACPY and an undesirable odour, as compared to the dark green ethanol extract, which contains a relatively larger quantity of ACPY and even more 3-methyl-2(5H)-furanone. Although at least 34 new components were uncovered from SC-CO2, SDE, and ethanol extraction, both ACPY and 3-methyl-2(5H)-furanone were the components tentatively obtained by all three methods. Copyright © 2004 John Wiley & Sons, Ltd. [source] Tyrosinase inhibitors isolated from the roots of Paeonia suffruticosaINTERNATIONAL JOURNAL OF COSMETIC SCIENCE, Issue 2 2010H. -Y. J. Cosmet. Sci., 60, 347,352 (May/June 2009) Accepted for publication November 6, 2008. Synopsis The inhibition of mushroom tyrosinase by Paeonia suffruticosa root-derived materials was evaluated. Six tyrosinase inhibitors were isolated by ethanol extraction, n -hexane, ethyl acetate, n -BuOH, and water partition, silica gel column chromatography, Sephadex LH-20, Lobar PR-8, and high-performance liquid chromatography methods, and they were identified as kaempferol (I), quercetin (II), mudanpioside B (III), benzoyloxypaeoniflorin (IV), mudanpioside H (V), and pentagalloyl-,-D-glucose (VI) on the basis of spectroscopic evidence. The inhibitory activities of compounds I to VI against mushroom tyrosinase were determined with IC50 values of 0.120, 0.108, 0.368, 0.453, 0.324, and 0.063 mM, respectively. The kinetic study indicated that all purified inhibitors acted competitively for the L-dopa binding site of the enzyme, with an exception of compound VI, which acted non-competitively. [source] | ||||||||||