Home About us Contact
|
Home About us Contact | ||
|
|
||
Extraction Yield (extraction + yield)
Selected AbstractsEXTRACTION YIELD OF SOLUBLE PROTEIN AND MICROSTRUCTURE OF SOYBEAN AFFECTED BY MICROWAVE HEATINGJOURNAL OF FOOD PROCESSING AND PRESERVATION, Issue 4 2006IL CHOI ABSTRACT A laboratory-scale microwave (MW)-assisted extraction system was constructed and compared with a conventional shaking water bath regarding the extraction of soluble proteins in soybeans. Dynamic reaction was monitored by response surface methodology in the MW-assisted extraction system. The yield of soluble protein increased until either temperature (T) or water/solid (W/S) ratio reached an optimum point (60.1C, 12.6 mL/g), and then decreased with further increase of T or W/S ratio. In addition, the yield of soluble protein increased with time within a range of 30 min, and no critical point was observed. The molecular mass of soluble protein was distributed from 19.3 to 81.3 kDa estimated by sodium dodecyl sulfate,polyacrylamide gel electrophoresis. Scanning electron microscopy showed the destruction of the microstructure of soybean cells, which increased the extraction of soluble soy protein. [source] Determination of vigabatrin in human plasma by means of CE with LIF detectionELECTROPHORESIS, Issue 19 2007Alessandro Musenga Abstract A method has been developed for the quantitation of the antiepileptic drug vigabatrin (VGB) in human plasma. It is based on CE with LIF detection. The effect of the pH of the buffer and of N -methylglucamine (GLC) as BGE constituent was investigated. The final BGE consisted of 50,mM borate buffer, pH,9.0, with 100,mM GLC and enabled separation within 12,min at 20,kV voltage. An SPE procedure was used for the pretreatment of biological samples, based on mixed-mode lipophilic-cation exchange cartridges, followed by a derivatization step with 6-carboxyfluorescein- N -succinimidyl ester (CFSE). Fluorescence was excited by an Ar-ion laser (,exc,=,488,nm). Linearity was observed in the 10,120,,g/mL plasma concentration range. Extraction yield was >96%, precision (expressed as RSD) <6.7% and accuracy (recovery) was between 97.0 and 101.6%. The method has been successfully applied to the analysis of VGB in plasma of epileptic patients undergoing therapy with the drug. [source] Determination of sertraline and N -desmethylsertraline in human plasma by CE with LIF detectionELECTROPHORESIS, Issue 11 2007Alessandro Musenga Abstract A method has been developed for the analysis of the antidepressant drug sertraline together with its main metabolite N -desmethylsertraline (DMS) in human plasma. It is based on CE with LIF detection (,,=,488,nm). A SPE procedure is employed for biological sample pretreatment, followed by a derivatization step with FITC; reboxetine was the internal standard. The effect of CD, acetone and N -methyl- D -glucamine (GLC) as constituents of the BGE for analyte separation was investigated. The final BGE consisted of 20,mM carbonate buffer, pH,9.0, with 2.5,mM heptakis(2,6-di- O -methyl)-,-CD, 50,mM GLC and 20% v/v acetone. With 30,kV applied voltage, the electrophoretic run is completed in 7.5,min. Linearity was observed in the plasma concentration range from 3.0 to 500,ng/mL for sertraline and 4.0 to 500,ng/mL for DMS. Extraction yield was >97.1%, precision , expressed as RSD% , was <3.7, accuracy (recovery) was >95.6%. Due to its sensitivity and selectivity, the method was suited for the analysis of plasma samples from patients undergoing therapy with sertraline. [source] Supercritical fluid extraction of walnut kernel oilEUROPEAN JOURNAL OF LIPID SCIENCE AND TECHNOLOGY, Issue 7 2006Sema Salg Abstract The objective of this study was to investigate the effects of the main process parameters on supercritical fluid extraction of walnut (Juglans regia,L.) kernel oil. The recovery of walnut kernel oil was performed in a green and high-tech separation process. CO2 and CO2 +,ethanol mixtures were used as the supercritical solvent. The extraction was carried out at operating pressures of 30, 40 and 50,MPa, operating temperatures of 313, 323 and 333,K, mean particle sizes of 1.78×10,4, 3.03×10,4, 4.78×10,4, 7.00×10,4 and 9.00×10,4,m, supercritical CO2 (SC CO2) flow rates of 1.67×10,8, 3.33×10,8, 6.67×10,8 and 13.33×10,8,m3/s and entrainer (ethanol) concentrations of 2, 4, 8 and 12,vol-%. Maximum extraction yield and oil solubility in SC CO2 obtained at 50,MPa, 333,K, 9.00×10,4,m, 3.33×10,4,m3/h were 0.65,kg oil/kg of dry sample and 37.16,g oil/kg CO2, respectively. The results obtained in this study showed that the crossover pressure effect of walnut kernel oil was at 30,MPa. At 30,MPa and 313,K, the obtained extraction yields above 4,vol-% ethanol reached the organic solvent extraction yield of 68.5,kg oil/kg dry sample. Extraction time was decreased significantly because of the higher solubility of walnut kernel oil in SC CO2 +,ethanol mixtures. [source] Optimisation study of gum extraction from Basil seeds (Ocimum basilicum L.)INTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 9 2009Seyed M. A. Razavi Summary Basil seed (Ocimum basilicum L.) is cultivated in large quantities in different regions of Iran. This seed has reasonable amounts of gum with good functional properties which is comparable with commercial food hydrocolloids. A central composite rotatable design was applied to evaluate the effects of temperature, pH and water/seed ratio on the yield, apparent viscosity and protein content of water-extracted Basil seed gum. All of the variables significantly (P < 0.05) affected the extraction yield, whereas the effect of water/seed ratio on apparent viscosity and the effects of pH and water/seed ratio on protein content were not significant (P > 0.05). Numerical optimisation determined the optimum extraction conditions based on the highest yield and viscosity and the lowest protein content as being temperature 68.71 °C, pH 8.09 and water/seed ratio 65.98:1. Power law model well described non-Newtonian pseudoplastic behaviour of BSG. Flow behaviour index (n) and consistency index (K) of 1% crude and pure BSG samples were 0.306, 0.283 and 17.46, 20.22 Pa sn, respectively. [source] The application of response surface methodology to the production of phenolic extracts of lemon grass, galangal, holy basil and rosemaryINTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 2 2006T. Juntachote Summary The effects of independent variables (ethanol:water ratio, temperature and time) on the extraction yield and antioxidant properties of phenolic extracts from lemon grass, galangal, holy basil and rosemary were studied. The extraction solvent ratio of ethanol to water was found to have a significant (P < 0.05) influence on extraction yield, reducing power and total phenolic content, but not on the antioxidant activity of all herb and spice samples, while extraction temperature had only minor effects. Extraction time had a significant (P < 0.05) effect only on the reducing power of holy basil extracts. The optimum extraction conditions, i.e. extraction solvent ratio of ethanol to water, extraction temperature and extraction time for maximum total phenolic content, were 3:1 at 25 °C for 30 min for lemon grass, 3:1 at 75 °C for 90 min for galangal and holy basil and 3:1 at 75 °C for 30 min for rosemary. [source] Supercritical CO2 extraction of accumulated capsidiol from biotic elicitor-activated Capsicum annuum L fruit tissuesJOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 2 2005ur Salg Abstract This work investigates the supercritical CO2 extraction of capsidiol from pepper fruit tissues activated with Alternaria alternate (Fr) Keissler suspension culture as a biotic elicitor. Capsidiol production in the fruit tissue was markedly increased by the treatment with a biotic elicitor and reached its maximum level after 4 days of elicitation. The effects of separation parameters such as temperature, pressure, supercritical solvent flow rate, particle diameter and also initial capsidiol concentration were investigated on solubility, initial extraction rate and extraction yield. The optimal extraction conditions were obtained at the temperature of 40 °C, the pressure of 400 bar, the supercritical CO2 flow rate of 2 cm3 min,1, and the average particle diameter of 116 µm. The results showed that the ratio of the supercritical CO2 extraction yield to the organic solvent extraction yield was changed from 84 to 97 wt-% depending on the initial capsidiol concentration. Copyright © 2004 Society of Chemical Industry [source] SUBCRITICAL WATER EXTRACTION OF CAFFEINE FROM BLACK TEA LEAF OF IRANJOURNAL OF FOOD PROCESS ENGINEERING, Issue 3 2008ANVAR SHALMASHI ABSTRACT This study examines subcritical water extraction (SCWE) of caffeine from black tea leaf. The effects of various operating conditions such as water temperature (100, 125, 150 and 175C), water flow rate (1, 2 and 4 g/min), mean particle size (0.5, 1 and 2 mm) on extraction yield and rate were determined. SCWE at 175C, water flow rate of 2 g/min and mean particle size of 0.5 mm were found to be able to recover 3.82% (w/w) of caffeine present in the black tea leaf within 3 h of extraction. In comparison to the SCWE, conventional hot water extraction showed 3.30% (w/w) extraction yield. It was found also that pressure had no effect on extraction yield and rate. PRACTICAL APPLICATIONS Recently, subcritical water has become of great interest as an alternative solvent for extraction of natural active compounds. Subcritical water, as a green solvent, can be used in many different fields of applications. In recent years, extraction of flavors, fragrances and antioxidant components from plant materials, and hydrolysis of carbohydrates, vegetable oils and fatty acids have been widely investigated by many researchers. Using subcritical water for analytical purposes, for soil remediation and applying it as a reaction media are some other interesting fields for practical applications. Subcritical water is an excellent solvent for caffeine as well as many other organic compounds but is safer than the organic solvents that are used for caffeine extraction. [source] SUPERCRITICAL 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] Extraction, Identification, and Quantification of Flavonoids and Phenolic Acids in Electron Beam-Irradiated Almond Skin PowderJOURNAL OF FOOD SCIENCE, Issue 3 2009A.S. Teets ABSTRACT:, The effect of electron beam irradiation doses from 0 to 30 kGy on extraction yield and phenolic compounds was evaluated in almond skin phenolic extracts (ASPE). Total soluble phenols and distribution of phenolic compounds from acidified methanol ASPE and 52% methanol ASPE were quantified using Folin,Ciocalteau method, liquid chromatography with diode array and fluorescence detection, and negative ion electrospray-mass spectrometry. Electron beam irradiation increased extraction yield by as much as 23%, with the greatest increase observed in the acidified methanol ASPE. Irradiated samples extracted with acidified methanol also exhibited an increase in extractable phenols (Folin,Ciocalteau) and total HPLC-resolved phenolics at all irradiation doses. Samples extracted with 52% methanol exhibited an increase at 10 and 20 kGy, but a 31% decrease at 30 kGy. An increase in aglycones respective to their glycosides was not observed with irradiation. Therefore, the increase in phenolics was attributed to release of phenolics from their cellular matrix. [source] Extraction Using Moderate Electric FieldsJOURNAL OF FOOD SCIENCE, Issue 1 2004I. SENSOY ABSTRACT: During moderate electric field (MEF) processing, a voltage applied across a food material may affect the permeability of cell membranes. It is known that high electric fields can cause either reversible or irreversible rupture of cell membranes. In this research, the effect of MEF processing on permeability was studied. Effects of frequency and electric field strength were investigated. Cellular structure was investigated by transmission electron microscopy (TEM). Fermented black tea leaves and fresh or dry mint leaves were placed in tea bags or cut in 1 cm2 squares, depending on the experiment, and immersed in an aqueous fluid medium. Control samples were heated on a hot plate. MEF treatments were conducted by applying a voltage across electrodes immersed in opposite sides of the beaker. Control and MEF-treated fresh mint leaf samples heated to 50°C were analyzed by TEM. MEF processing significantly increased the extraction yield for fresh mint leaves because of additional electric field effects during heating. Dried mint leaves and fermented black tea leaves were not affected by the treatment type. Low frequency resulted in higher extraction rates for fresh mint leaves. The electric field strength study showed that electrical breakdown is achieved even at low electric field strengths. MEF treatment shows potential to be used as an alternative to conventional heating for extraction from cellular materials. [source] Aqueous Extraction and Membrane Isolation of Protein from Defatted Gevuina avellanaJOURNAL OF FOOD SCIENCE, Issue 2 2002A. Moure ABSTRACT: Proteins from defatted Gevuina avellana seeds were extracted in aqueous media. Protein extraction was limited at liquid-to-solid ratios under 12 g/g, but was not significantly affected by temperatures in the 25 to 45 °C range. The maximum protein extractability occurred both at acidic and alkaline pH; the presence and concentration of NaCl affected it differently, depending on the extraction pH. Up to 3 extraction stages with whey recycle after ultrafiltration were performed, without affecting the protein extraction yield. The functional properties of the protein isolated with membranes were similar or better than those from isoelectric precipitation. [source] Fast CE analysis of adrenergic amines in different parts of Citrus aurantium fruit and dietary supplementsJOURNAL OF SEPARATION SCIENCE, JSS, Issue 16 2010Laura Mercolini Abstract A CE method has been developed for the simultaneous analysis of the adrenergic amines synephrine, octopamine and tyramine in Citrus aurantium (bitter orange) fruit extracts and in dietary supplements. The analytes were separated on a fused silica capillary (50,,m id, 40.0,cm effective length, 48.5,cm total length) using a BGE composed of phosphate buffer (pH 2.5, 50,mM) and applying a 30,kV potential. The samples were injected hydrodynamically at 50,mbar for 25,s. The use of photodiode array detection (,=195,nm) allowed the quantification of the analytes and the control of peak purity. The method has been fully validated, obtaining satisfactory values of precision and extraction yield. The analytes are extracted with water from the dried whole fruits or fruit parts (endocarp, mesocarp and exocarp) or from the commercial formulations and directly injected into the CE apparatus. The results obtained were satisfactory in terms of precision (RSD <,5.7%) and accuracy (recovery >,89%). Thus, the method has demonstrated to be suitable for the qualitative and quantitative determination of synephrine, octopamine and tyramine in C. aurantium extracts, for dietary supplement quality control and for food adulteration identification. [source] Supercritical fluid extraction of cynaropicrin and 20-hydroxyecdysone from Leuzea carthamoides DCJOURNAL OF SEPARATION SCIENCE, JSS, Issue 8 2008Helena Sovová Abstract Leuzea carthamoides is an adaptogenic plant containing biologically active compounds as ecdysteroids and guaianolide-type sesquiterpene lactones, conventionally extracted from the plant with ethanol. It may be a potential source of the mentioned natural compounds. Ethanol-modified near-critical CO2 was used as selective solvent with the aim to increase the level of 20-hydroxyecdysone in the extract from L. carthamoides roots and to remove selectively cynaropicrin, a sesquiterpene lactone of bitter taste, from the leaves. The extraction conditions were varied (pressure 20,28 MPa, temperature 40,60°C, ethanol concentration in the solvent 0,7.1%) and the extraction yield and extract composition were compared with the results of ethanolic extraction. The supercritical fluid extraction (SFE) from finely powdered plant was controlled by phase equilibrium. Cynaropicrin was quantitatively removed from the leaves where 89% of 20-hydroxyecdysone was retained. The extraction yield of 20-hydroxyecdysone from roots with ethanol-modified CO2 was lower by 30% than with ethanol but its concentration in the extract was higher by 67%. [source] Characterization via liquid chromatography coupled to diode array detector and tandem mass spectrometry of supercritical fluid antioxidant extracts of Spirulina platensis microalgaJOURNAL OF SEPARATION SCIENCE, JSS, Issue 9-10 2005Jose A. Mendiola Abstract Spirulina platensis microalga has been extracted on a pilot scale plant using supercritical fluid extraction (SFE) under various extraction conditions. The extraction yield and the antioxidant activity of the extracts were evaluated in order to select those extracts with both the highest antioxidant capacity and a good extraction yield. These extracts were characterized using LC coupled to diode array detection (DAD) and LC coupled to mass spectrometry (MS) with two different interfaces, atmospheric pressure chemical ionization (APCI) and electrospray (ESI) which allowed us to perform tandem MS by using an ion trap analyzer. The best extraction conditions were as follows: CO2 with 10% of modifier (ethanol) as extraction solvent, 55°C (extraction temperature) and 220 bar (extraction pressure). Fractionation was achieved by cascade depressurization providing two extracts with different activity and chemical composition. Several compounds have been identified in the extracts, corresponding to different carotenoids previously identified in Spirulina platensis microalga along with chlorophyll a and some degradation products. Also, the structure of some phenolic compounds could be tentatively identified. The antioxidant activity of the extracts could be attributed to some of the above mentioned compounds. [source] Optimization of enzymatic extraction of ferulic acid from wheat bran, using response surface methodology, and characterization of the resulting fractionsJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 10 2009Hélène Barberousse Abstract BACKGROUND: The agro-industries generate thousands of tons of by-products, such as bran or pulps, each year. They are, at best, used for cattle feeding. Through biocracking, this biomass may constitute a renewable source for various molecules of interest for the industry. For instance, ferulic acid, a compound showing antioxidant ability, is found in abundance in cereal bran. Its release depends mainly on the breaking of its ester linkage to other constitutive elements of the cell wall, such as arabinoxylans. Response surface methodology was used to evaluate the effects of ferulic acid esterase (FAE) and xylanase activities, as well as incubation time and temperature, on ferulic acid extraction yield from wheat bran. Under optimized conditions, the composition of the hydrolysate and of residual bran were compared to native bran. RESULTS: Experiments carried out under the predicted optimal conditions (FAE amount, 27 U g,1; xylanase amount, 304 U g,1; incubation time, 2 h; and temperature, 65 °C) led to an extraction yield of 52.8%, agreeing with the expected value (51.0%). The crude ferulic acid fraction was purified with Amberlite XAD16, leading to a final concentration of 125 µg mL,1 of ferulic acid in ethanol. The antioxidant capacity of this purified fraction was evaluated by the DPPH· scavenging method: it exhibited better efficiency (EC50 = 10.6 µmol L,1 in ferulic acid) than the ferulic acid standard (EC50 = 13.7 µmol L,1). CONCLUSION: These results confirm the potential of wheat bran valorization in the field of natural antioxidant extraction, possibly viable in an industrial scheme. Copyright © 2009 Society of Chemical Industry [source] Supercritical carbon dioxide extraction of sea buckthorn (Hippophae rhamnoides L.) pomaceJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 13 2007Dániel Cossuta Abstract BACKGROUND: The goal of this work was to utilize the sea buckthorn pomace, which is the by-product of a sea buckthorn juice process. Pilot plant supercritical fluid extraction (SFE) experiments were performed in a 5 × 10,3 m3 volume high-pressure vessel. The effects of pressure and temperature on extraction yield and recoveries of biologically active components were studied using a 32 full factorial design. The pressure and temperature were varied over the ranges of 30,46 MPa and 313,353 K, respectively. The extract samples were analysed by TLC-densitometry, UV/VIS spectrofotometry and HPLC methods. RESULTS: The obtained yields changed between 142,164 g kg,1, according to the solvent power of the supercritical fluid. The recoveries of the different minor components were (g minor components kg,1 dried raw material): 2.50,4.25 sitosterol, 0.20,1.60 ursolic acid, 0.04,0.18 carotenoid, 0.35,0.42 total tocopherol. CONCLUSION: By evaluation the designed experiments 46 MPa and 333 K were chosen as the optimum conditions. Copyright © 2007 Society of Chemical Industry [source] Production of luteolin extracts from Reseda luteola and assessment of their dyeing propertiesJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 10 2002Alfonso Cerrato Abstract In this work, several experiments were performed sequentially in 50,cm3 shaken tubes and a 1,dm3 stirred extractor, thus allowing methanol to be selected as the most appropriate leaching solvent for luteolin from leaves, stems and flowers of weld (Reseda luteola). The extraction capability of methanol at 25,°C was found to be about 7 times greater than that of boiling water at pH 10. A composite design experiment allowed the effects of particle size and liquid/solid ratio to be determined, thus resulting in an optimal luteolin extraction yield of 8.6,±,0.2,g,kg,1 dried weld material when leaching plant particles sieved through 0.5,mm openings with 40,dm3 methanol kg,1. Preliminary dyeing tests on pre-mordanted raw cotton and wool standard specimens gave rise to dyed specimens with the same greenish-yellow hue but greater or smaller values of lightness and chroma respectively. Despite all dyed specimens exhibiting a minimum resistance to a simulated acid perspiration solution, the resistance to fading of dyed wool specimens was generally greater than that of cotton ones. © 2002 Society of Chemical Industry [source] Safety and quality of plastic food contact materials.PACKAGING TECHNOLOGY AND SCIENCE, Issue 5 2003Optimization of extraction time, based on arithmetic rules derived from mathematical description of diffusion., extraction yield Abstract Migration of packaging constituents into food may raise concerns about food safety. This paper describes the conclusions of a EU research project (AIR 941025), aiming to facilitate the introduction of migration control into good manufacturing practice and into enforcement policies. The first part describes a re-evaluation of analytical approaches to extract and identify potential migrants released by plastic materials, viz. comparison of analytical methods, choice of extraction solvents and of fat simulants. Here we focus on the extraction time needed to achieve a given extraction yield. By correlating these parameters with simple and practical equations, it is possible to design alternative tests for control of compliance of packaging plastics. Using a reference experiment (where there is good agreement between experimental and calculated kinetic curves), it is possible to calculate the percentage of extraction which can be achieved in a given time, or the time necessary to reach a target extraction level for other polymer/solvent combinations. A global control scheme is proposed, which indicates whether and when calculation and testing should be applied. Guidelines are proposed, and can be adapted to both industrial control and to enforcement laboratories. Copyright © 2003 John Wiley & Sons, Ltd. [source] Effect of solvent concentration on the extraction kinetics and diffusivity of Cyclosporin A in the fungus Tolypocladium inflatumBIOTECHNOLOGY & BIOENGINEERING, Issue 1 2007May Ly Abstract The kinetics of solid-liquid extraction and extraction yields of the immunosuppressant drug Cyclosporin A (CyA) from the mycelia of Tolypocladium inflatum were examined in this study. A 2 L stirred, baffled vessel was used to extract CyA from wet mycelia mass. Three different organic solvents were used, namely, methanol, acetone, and isopropanol at different concentrations in aqueous mixtures at room temperature. It was found that the best solvent was acetone at 50% v/v concentration achieving 100% extraction of CyA from the mycelia of T. inflatum. Although acetone proved to be the better solvent for CyA extraction, further studies were performed using methanol. A linear relationship was found between extraction yield of CyA and methanol concentration with 100% CyA extraction at 90% v/v methanol. The partition coefficients of CyA between the solid mycelia phase and the aqueous solvent phase were found to decrease exponentially with increasing methanol concentration. A liquid extraction model was developed based on the diffusion equation to correlate the kinetic data of CyA extraction from the solid mycelia of T. inflatum. Non-linear regression analysis of experimental data was used with the diffusion equation in order to calculate the effective diffusivities of CyA in the mycelia of T. inflatum. For all three organic solvents used, the effective diffusivities of CyA were found to be between 4.41,×,10,15 and 6.18,×,10,14 m2/s. This is the first time CyA effective diffusivities in T. inflatum are reported in the literature. Biotechnol. Bioeng. 2007;96: 67,79. © 2006 Wiley Periodicals, Inc. [source] Optimization of Allium sativum Solvent Extraction for the Inhibition of in Vitro Growth of Helicobacter PyloriBIOTECHNOLOGY PROGRESS, Issue 6 2002Pablo Cañizares Helicobacter pylori (Hp) is the bacterium responsible for serious gastric diseases such as ulcers and cancer. The work described here involved the study of the inhibitory power of Allium sativum extracts against the in vitro growth of Hp(Hp ivg). We used purple garlic of the "Las Pedroñeras" variety for this study. The effects of two different extraction methods (Soxhlet, stirred tank extractor) and four solvents with different characteristics (water, acetone, ethanol, and hexane) were investigated in terms of the efficiency of the extraction process. Satisfactory results were obtained in most cases in the activity tests, indicating that different extracts gave rise to good inhibitory activity against Hp ivg. The extracts that showed the highest bacteriostatic activities were selected to evaluate the influence of the most important operation variables on the extraction yield: stirring speed, operation time, garlic conditioning, and garlic storage time. The best results were obtained using ethanol and acetone as solvents in a stirred tank. The inhibitory powers of these extracts were compared to those shown by some commercial antibiotics used in the medical treatment of Hp infections. The results of this study show that garlic extracts produce levels of inhibition similar to those of the commercial materials. These extracts were also tested against other common bacteria, and equally satisfactory results were obtained. The research described here represents an important starting point in the fight against and/or prevention of peptic ulcers, as well as other pathologies associated with Hp infections such us gastric cancer. The extracted material can be used by direct application and involves a simple and economical extraction procedure that avoids isolation or purification techniques. [source] Supercritical CO2 Extraction of Essential Oil from Algerian Rosemary (Rosmarinus officinalis,L.)CHEMICAL ENGINEERING & TECHNOLOGY (CET), Issue 3 2010A. Zermane Abstract The present study presents experimental results concerning the supercritical CO2 extraction of essential oil from Algerian rosemary leaves. The effects of key operating parameters such as pressure, temperature, particle size and CO2 mass flow rate on the extraction yield were investigated. The obtained yields were in the range of 0.95,3.52,g oil/g dry rosemary, and the best value was observed at a pressure of 22,MPa, a temperature of 40,°C, a flow rate of 7,g/min, and a particle size of 1,mm. The performance of the local rosemary used was assessed by comparison of the obtained yields with values reported in the literature for essential oils derived from different rosemary sources. The GC and the GC-MS analyses showed that the major compound detected in the essential oil was camphor, at 48.89,wt,%. [source] Effects of Operating Parameters on the Cinnamaldehyde Content of Extracted Essential Oil Using Various MethodsCHEMICAL ENGINEERING & TECHNOLOGY (CET), Issue 2 2010H. Baseri Abstract Supercritical fluid extraction (SFE) of essential oils from commercial cinnamon bark was compared with essential oils that were obtained by hydrodistillation. Effects of operating parameters (pressure, temperature and extraction time of SFE) on the extraction yield and the composition of the extracted volatile oil were studied. Moreover, in the hydrodistillation process, the effect of the pH of the solvent on the concentration of cinnamaldehyde in the extracted volatile oil was studied. The maximum yield of extract in the SFE process is about 7.8,% at 70,°C and 240,bar. The maximum concentration of cinnamaldehyde in the SFE process was obtained at 70,°C and 160,bar, and the maximum concentration of this component in hydrodistillation was achieved at pH,=,4.1. [source] Supercritical fluid extraction of walnut kernel oilEUROPEAN JOURNAL OF LIPID SCIENCE AND TECHNOLOGY, Issue 7 2006Sema Salg Abstract The objective of this study was to investigate the effects of the main process parameters on supercritical fluid extraction of walnut (Juglans regia,L.) kernel oil. The recovery of walnut kernel oil was performed in a green and high-tech separation process. CO2 and CO2 +,ethanol mixtures were used as the supercritical solvent. The extraction was carried out at operating pressures of 30, 40 and 50,MPa, operating temperatures of 313, 323 and 333,K, mean particle sizes of 1.78×10,4, 3.03×10,4, 4.78×10,4, 7.00×10,4 and 9.00×10,4,m, supercritical CO2 (SC CO2) flow rates of 1.67×10,8, 3.33×10,8, 6.67×10,8 and 13.33×10,8,m3/s and entrainer (ethanol) concentrations of 2, 4, 8 and 12,vol-%. Maximum extraction yield and oil solubility in SC CO2 obtained at 50,MPa, 333,K, 9.00×10,4,m, 3.33×10,4,m3/h were 0.65,kg oil/kg of dry sample and 37.16,g oil/kg CO2, respectively. The results obtained in this study showed that the crossover pressure effect of walnut kernel oil was at 30,MPa. At 30,MPa and 313,K, the obtained extraction yields above 4,vol-% ethanol reached the organic solvent extraction yield of 68.5,kg oil/kg dry sample. Extraction time was decreased significantly because of the higher solubility of walnut kernel oil in SC CO2 +,ethanol mixtures. [source] SUPERCRITICAL CARBON DIOXIDE SELECTIVITY TO FRACTIONATE PHENOLIC COMPOUNDS FROM THE DRY ETHANOLIC EXTRACT OF PROPOLISJOURNAL OF FOOD PROCESS ENGINEERING, Issue 1 2010LOSIANE C. PAVIANI ABSTRACT The global yield and composition of extracts obtained by supercritical carbon dioxide (SC-CO2) extraction from a dry ethanolic extract of propolis were measured in order to determine the possibility of using SC-CO2 to fractionate components of interest present in these extracts. The global yield extraction was measured, and also the concentrations of the following phenolic compounds in the resulting supercritical fluid extracts (SFEs): 3,5-diprenyl-4-hydroxycinnamic acid (known as artepillin C), 3-prenyl-4-hydroxycinnamic acid, 4-hydroxycinnamic acid (p- coumaric acid) and 4-methoxy-3,5,7-trihydroxyflavone (kaempferide), of which artepillin C was the target component of greatest interest. The results showed extraction yields between 3.82 (at 150 bar) and 13.07% (at 350 bar), which could be highly correlated with the density of the SC-CO2 at a constant temperature of 60C. The resulting concentrations in the SFE indicated that the selectivity of the carbon dioxide could be manipulated, and it was more selective at lower pressures, although with lower extraction yields. PRACTICAL APPLICATIONS Supercritical fluid extraction is an interesting process for the production of natural extracts because it is a clean process, and extractions using carbon dioxide (CO2) as the solvent have been gaining attention in recent years. This study presented important aspects with respect to the fractionation of a dry ethanolic extract of propolis using supercritical carbon dioxide, and it is important to explore the potential applications of propolis extracts and the biological properties of its fractions in the food, pharmaceutical and cosmetic industries, such as in dental hygiene products, wound healing creams and antibacterial soaps. [source] SUPERCRITICAL 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] FTIR-spectroscopic characterization of humic acids and humin fractions obtained by advanced NaOH, Na4P2O7, and Na2CO3 extraction proceduresJOURNAL OF PLANT NUTRITION AND SOIL SCIENCE, Issue 4 2007Michael Tatzber Abstract Aim of our study was the development of the methodological basis for the characterization of humic fractions of a long-term field experiment. Humic acids (HAs) were extracted from three layers of a nontilled soil using three different extractants (1 M NaOH, 0.1 M Na4P2O7, 1 M Na2CO3), and the humin fraction was enriched. NaOH as extractant for FTIR analysis of humic substances yields higher resolved IR spectra, especially in the important regions of stretching vibrations including aromatic and aliphatic groups and in the fingerprint area including amides, aliphats, and aromats than the other extractants. The NaOH extraction has lower extraction yields as compared to Na4P2O7 and Na2CO3 and represents a different part of the soil organic matter (SOM). This is reflected by lower C : N ratios and higher E4 : E6 and fulvic acid,to,humic acid ratios as compared to the other extractants. The FTIR band areas of HA fraction obtained by NaOH showed an increase of the aromatic and carbonyl groups and a decrease of amide groups with increasing soil depth. Aliphatic groups showed contradicting results: The bands of the stretching vibrations increased, and the band of the bending vibrations decreased. We assume that band interactions in the bending vibrations were responsible for that phenomenon under the assumption of an increase of aliphatic groups with increasing soil depth. The IR bands of the enriched humin fraction showed a decreasing trend in case of both aliphatic bands deriving from stretching vibrations and an increase of aromatic characteristics with depth. Our study led to the conclusion that HA fractions obtained by 1 M NaOH represent a small and dynamic fraction indicated by the measured yields in combination with values of Nt, C : N, E4 : E6 ratios, and ratios of fulvic acids (FA) to HA. The humin fraction has a high contribution to the total organic C and represents a more stabilized fraction of SOM which still shows changes in its aromatic and aliphatic characteristics with soil depth. [source] Selective ultrasound-assisted extractions of lipophilic constituents from Betula alleghaniensis and B. papyrifera wood at low temperaturesPHYTOCHEMICAL ANALYSIS, Issue 4 2007J.-M. Lavoie Abstract Betula alleghaniensis and B. papyrifera are widely distributed in the province of Québec (Canada) and, since these trees are valuable exports for the local lumber industry, large amounts of their residual ligneous biomass are available for further exploitation. Betula species are well known for their significant concentrations of triterpenes, some of which were recently discovered to present promising bioactivity. The secondary transformation of birch biomass could therefore become important for many industries, particularly the pharmaceutical industry. In the present study, extracts from birch sawdust were obtained using an optimised ultrasound-assisted extraction in which the careful choice of temperature permitted a selective extraction of the targeted triterpenes. Moreover, compared with the classical Soxhlet method, higher extraction yields were obtained in a shorter time. The lipophilic extracts obtained using dichloromethane as a solvent were analysed by GC-MS and the major compounds identified as lupane-type cyclic triterpenoids accompanied by the non-cyclic triterpene squalene. Numerous aliphatic long-chain fatty acids were also found in the extracts together with phytosterols. Betulonic acid and squalene, the major extract constituents for both B. alleghaniensis and B. papyrifera, are both bioactive molecules. Copyright © 2007 John Wiley & Sons, Ltd. [source] Enhanced solvent extraction of polar lipids associated with rubber particles from hevea brasiliensisPHYTOCHEMICAL ANALYSIS, Issue 2 2007Frederic Bonfils Abstract Biochemical studies of lipids bound to rubber particles have been complicated due to the solubility of polyisoprene chains in most extracting solvents and the rather delicate nature of polar lipids that are often denatured when traditional solvent extraction techniques are employed. In this paper, we describe a traditional technique and accompanying solvents that permit optimal extraction of rubber particle bound lipids. The technique, which is validated after characterizing the lipid extracts by elemental analysis, silica column adsorption and thin layer chromatography, appeared more suitable for extracting total lipids with optimal glycolipid and phospholipid contents. This technique is proposed as an alternative to traditional extraction methods used for solid natural rubber as it offers advantages with respect to ease of application, extract quality, extraction yields and reproducibility. Copyright © 2007 John Wiley & Sons, Ltd. [source] Comparison of three methods for the extraction of arsenic compounds from the NRCC standard reference material DORM-2 and the brown alga Hijiki fuziformeAPPLIED ORGANOMETALLIC CHEMISTRY, Issue 6 2001Doris Kuehnelt Abstract The NRCC standard reference material DORM-2 and the marine brown alga Hijiki fuziforme were extracted with water, methanol/water (9,+,1), and 1.5 M orthophosphoric acid. The extracts from DORM-2 were analyzed by HPLC,ICP-MS for arsenobetaine, arsenocholine, trimethylarsine oxide, and the tetramethylarsonium cation and the extracts from H. fuziforme for arsenous acid, arsenic acid, dimethylarsinic acid, methylarsonic acid, and four arsenoriboses. Almost no differences between the three extractants were observed when DORM-2 was investigated. Only arsenobetaine was slightly better extracted with 1.5 M orthophosphoric acid or methanol/water (9,+,1) than with water. The sum of all extractable compounds (arsenobetaine, the tetramethylarsonium cation, and a formerly unknown compound recently identified as the trimethyl(2-carboxyethyl)arsonium ion) accounted for 94% of the total arsenic when 1.5 M orthophosphoric acid was used, for 92% when methanol/water (9,+,1) was used, and for 87% when water was used. Significant differences in the extraction yields obtained for the alga were observed for arsenic acid and one of the arsenoriboses (,glycerol-ribose'). Orthophosphoric acid removed twice as much of this ribose from the algal material than water and three times more than methanol/water (9,+,1). Arsenic acid was 1.2 times better extracted with orthophosphoric acid than with water and ten times better than with methanol/water (9,+,1). Almost no differences in the extraction yields were found for dimethylarsinic acid and the other three riboses. Orthophosphoric acid extracted 76%, water 65%, and methanol/water 33% of the total arsenic from H. fuziforme. Copyright © 2001 John Wiley & Sons, Ltd. [source] | ||||||||||||||||