bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of methyl tert‐butyl ether in standard tests for mutagenicity and environmental toxicity
Authors: Vosahlikova Miluse , Cajthaml Tomas , Demnerova Katerina , Pazlarova Jarmila 
Published: November 2006

AbstractMethyl tert‐butyl ether (MTBE) is a synthetic compound that is used as a technological solution to problems created by air pollution from vehicle emissions. An important source of MTBE in the environment is leakage from underground storage tanks at gasoline stations or accidents during gasoline transport. The aim of this study was to evaluate the risk of MTBE leakage for the environment using the Microtox® (Vibrio fischeri) toxicity test, Lactuca sativa seed germination test, and Ames bacterial mutagenicity test with Salmonella typhimurium his− strains TA98, TA100, YG1041, and YG1042, using both standard plate and preincubation protocols. The result of Microtox® expressed as EC50 was 33 mg (MTBE)/L. The effect of all tested MTBE concentration (0.05, 0.50, and 1.00% v/v) on Lactuca sativa roots elongation was negative and proved its toxicity. The highest tested concentration of MTBE that could be tested in Ames test was 3 mg (MTBE)/plate, because of cytotoxicity. No mutagenic response was observed at this or lower concentrations in any of the four strains used. © 2006 Wiley Periodicals, Inc. Environ Toxicol 21: 599–605, 2006.
Kinetics of acyl migration in monoglycerides and dependence on acyl chainlength
Authors: Boswinkel G. , Derksen J. T. P. , van't Riet K. , Cuperus F. P. 
Published: November 2006

AbstractThe chemical rearrangement reaction of β‐ into α‐monoglycerides is described. Four monoglycerides with different fatty acid chainlength have been investigated, and the equilibrium constant and the reaction velocity constants characterizing the reaction of the chemical rearrangement were estimated with a mathematical model. A 1∶6.5 mixture of α/β‐monoglycerides appeared to rearrage to a mixture of 1∶1 α/β‐monoglycerides within 24 h. Furthermore, the reaction velocity of the rearrangement reaction of β‐ to α‐monoglycerides depended on the fatty acyl chainlength in the monoglyceride.
Supercritical fluid extraction of meat lipids: An alternative approach to the identification of irradiated meats
Authors: Hampson James W. , Jones Kerby C. , Foglia Thomas A. , Kohout Karen M. 
Published: November 2006

AbstractIonizing radiation is currently under study as an alternative method for extending the shelf life of meats and meat products. Accordingly, methods are needed to determine if a meat or meat product has been exposed to ionizing radiation. In this study, a method is described for the isolation and analysis of volatile hydrocarbons formed in meat lipids after exposure to ionizing radiation. The method is based on supercritical fluid extraction of the hydrocarbons from meat lipids and subsequent identification and quantitation of individual hydrocarbons by gas chromatography (GC) with a mass selection detector (MSD). Supercritical carbon dioxide at 175 bar and 40°C extracted the hydrocarbon fraction from total meat lipids within 20 min. The presence of radiolytic hydrocarbons, as determined by GC/MSD, was then correlated to the degree of irradiation of the meat from 0 to 10 kGy. Besides being faster, this method has the advantage of reduced solvent consumption when compared to current methods for determining if a meat or meat product has been irradiated.
Purification and characterization of a lipase fromNeurospora sp. TT‐241
Authors: Lin Shuen‐fuh , Lee Jane‐Chyi , Chiou Chien‐Ming 
Published: November 2006

AbstractAn extracellular lipase, which is produced by theNeurospora sp. TT‐241 strain, grown on wheat bran at 30°C for 4 d, was purified 370‐fold with an overall yield of 16%. The molecular weight was determined to be 55 kDa by sodium dodecyl sulfate‐polyacrylamide gel electrophoresis. The optimal pH at 30°C and optimal temperature at pH 6.5 were 7 and 45°C, respectively. The lipase was stable in the pH range of 5 to 8, and it was temperature‐sensitive. It was active on a wide range of natural substrates of either vegetable or animal origins and towardp‐nitrophenyl esters, greatly favoring those containing C4 acyl groups. It cleaved all of the ester bonds of triolein; however, the 1‐ or 3‐ester bond was the preferred target. A complete inhibition by diisopropyl fluorophosphate suggested the presence of a serine residue at the active site. Partial inhibition was shown by either Hg2+ or chloramine T. Enzyme activity persisted in nonionic surfactants, a water‐miscible solvent (dimethylsulfoxide), and a water‐immiscible solvent (hexane).
Droplet composition affects the rate of oxidation of emulsified ethyl linoleate
Authors: Coupland J. N. , Zhu Z. , Wan H. , McClements D. J. , Nawar W. W. , Chinachoti P. 
Published: November 2006

AbstractOur objective was to study the influence of droplet composition on the rate of lipid oxidation in emulsions. A series of oil‐in‐water emulsions stabilized by a nonionic surfactant (Tween 20) was studied. These emulsions had the same total oil concentration (5 wt%) and initial droplet diameter (0.3 μm), but contained droplets with different ratios of ethyl linoleate (substrate) andn‐tetradecane (inert diluent). Lipid oxidation was measured as a function of time by three different methods: gas‐chromatographic determination of residual substrate; ultraviolet‐visible spectrophotometric determination of conjugated dienes; and measurement of aqueous thiobarbituric acid‐reactive substances. All three methods showed similar trends for emulsions of similar composition. The progress of lipid oxidation in the emulsions was dependent on the concentration of ethyl linoleate in the emulsion droplets. At low concentrations (1% oil as substrate), oxidation proceeded at a relatively slow and constant rate. At intermediate concentrations (20%), the oxidation rate was rapid initially and then slowed down with time. At high concentrations (100%), the oxidation rate was slow at first, and then increased with time. An explanation of our results is proposed in terms of the distribution of substrate molecules between the droplet interior and interface, and the ingress of aqueous radicals into the emulsion droplets.
Characteristic properties of cutting fluid additives derived from half esters of dimer acids
Authors: Watanabe S. , Nakagawa H. , Ohmori Y. , Fujita T. , Sakamoto M. , Haga T. 
Published: November 2006

AbstractA number of half esters were prepared from the reaction of alcohols with dimer acids and screened for anti‐rust properties and antimicrobial activity in spent coolants of water‐based cutting fluids. Aqueous solutions of triethanolamine salts with lower‐alcohol half esters of dimer acid showed good anti‐rust properties for water‐based cutting fluids.
Syntheses of long‐chain quaternary ammonium salts from fatty alcohols by microwave irradiation
Authors: Jiang Yu‐Lin , Hu Yu‐Qiao , Pang Jun , Yuan Yun‐Cheng 
Published: November 2006

AbstractThe phase‐transfer catalysts, long‐chain quaternary ammonium salts, were rapidly synthesized from fatty alcohols by the reactions with hydrogen halides in the presence of trialkyl amines under microwave irradiation. The catalysts could be widely applied in a variety of quick and new organic reactions, whether by conventional heating or under microwave irradiation. The reaction efficiencies under microwave irradiation were higher than those obtained with conventional heating.
Surface‐tension properties of some polydispersed alkyl‐substituted polyoxyethylated phenylsulfonamides
Authors: Hampson J. W. , Cornell D. G. 
Published: November 2006

AbstractTwenty‐nine laboratory‐prepared polydisperse nonionic surfactants, derived from polyoxyethylatedN‐alkylphenylsulfonamides [RϕSO2 N(R′) (EO)nH], have been characterized. EO is ethyoxylation;R is hydrogen,n‐butyl ort‐butyl;R′ is hexyl, octyl, or decyl; and (EO)n is varied from (EO)4 to (EO)20. Surface tension in aqueous solution was studied. The critical micelle concentration, surface excess, minimum area per molecule, effectiveness of surface‐tension reduction, and free energy of micelle formation were calculated from the surface‐tension measurements. The critical micelle concentrations for the derivatives in whichR′‐hexyl were considerably higher than the corresponding derivatives whereR′ is octyl or decyl. The greatest surface‐tension reduction was found in theR′=n‐octyl derivatives whereR ist‐butyl with (EO)9 orn‐butyl with (EO)11.
Pushing the frontiers of multicultural training in community psychology
Authors: Weinstein Rhona S. 
Published: November 2006

AbstractSuarez‐Balcazar, Durlak, and Smith (1994) have provided the field with important baseline information regarding multicultural training practices in community psychology. This report can serve as a catalyst in our quest to place an understanding of human diversity, in particular, ethnic‐cultural diversity, at the heart of community psychology. To do so, we need to move beyond the teaching of culturally sensitive research and practice to a reconceptualization of the knowledge base and methods of community psychology, to an examination of the conflicts engendered by the inclusion of multiple voices, and to the implementation of institutional arrangements that can support such a challenging task in constructive ways.
Purification and characterization of deep sea sharkCentrophorus squamosus liver oil 1‐O‐aklylglycerol ether lipids
Authors: Bordier Catherine G. , Sellier Nicole , Foucault Alain P. , Le Goffic François 
Published: November 2006

AbstractThe 1‐O‐alkylglycerol composition of the liver oil of the deep sea sharkCentrophorus squamosus, a species which provides edible flesh, has been determined. After various fractionations of the oil, the unsaponifiable fraction was characterized by means of gas chromatography/mass spectrometry, electron impact, and positive‐ion chemical ionization. The oil is composed of 60% unsaponifiable matter, containing 45% squalene, 4.5% cholesterol, and 10% of linear saturated and monounsaturated glycerol ethers with 14–18 carbon atoms. After a first separtion by chromatography on silicic acid, monounsaturated glycerol ethers have been separated from the saturated homologues, in particular from 1‐O‐octadecylglycerol (batyl alcohol) and 1‐O‐hexadecylglycerol (chimyl alcohol)via urea complexation. This newer application of the urea method, already used in the past to extract saturated from polyunsaturated fatty acids, allowed the purification of the main components of the complex unsaturated glycerol ether fraction, namely, 1‐O‐octadecen‐9′ylglycerol (selachyl alcohol) and 1‐O‐hexadecen‐9′ylglycerol.
Microscale preparation of natural and labeled oxysterols
Authors: Krut Louis H. , Schonfeld Gustav , Ostlund Richard E. 
Published: November 2006

AbstractThe preparation of cholesterol and radiocholesterol oxidation products on a microscale is difficult. Cholesterol generally resists oxidation unless it is well dispersed under controlled conditions. A method was developed to reliably produce 7α‐ and 7β‐hydroxycholesterol and 7‐ketocholesterol. Small changes in pH, metal ions present, or in the colloidal dispersion, resulted in production of completely different oxysterols. Attempts to oxidize aged radiocholesterol were not successful even after purification by several thin‐layer chromatographic steps, and this appeared to be due to a time‐related change in the radioactive material. Fresh radiocholesterol oxidized readily.
Synthesis of 1,2‐diacyl‐sn‐glycerophosphadidylserine from egg phosphatidylcholine by phosphoramidite Methodology
Authors: Morillo Margarita , Sagristá M. Luisa , Africa de Madariaga M. , Eritja Ramón 
Published: November 2006

AbstractA simple chemical method for the synthesis of 1,2‐diacyl‐sn‐glycerophosphatidylserine (PS), with the same fatty acid composition in thesn‐1 andsn‐2 glycerol positions as egg phosphatidylcholine (PC), is described. PS synthesis was carried out by a phosphite‐triester approach, using 2‐cyanoethyl‐N,N,N′,N′‐tetraisopropylphosphorodiamidite (phosphoramiditate) as the phosphorylating agent, for the formation of phosphate linkage between serine and diacylglycerol. 1,2‐Diacylglycerol, obtained from PC hydrolysis by phospholipase C, was coupled withN‐t‐BOC‐l‐serinebenzhydryl ester phosphoramidite with tetrazole as catalyst. Phosphite‐triester was oxidized to the corresponding phosphate‐triester with 30% H2O2 in CH2Cl2. The cyanoethyl group was removed by addition of an Et3N/CH3CN/pyridine mixture, and trifluoroacetic acid was used to eliminate the protecting groups ofO‐(1,2‐diacylglycero‐3‐phospho)‐N‐t‐BOC‐serinebenzhydril ester. Purified PS was identified by thin‐layer chromatography, infrared, and1H nuclear magnetic resonance.
Ethanol extraction of polyphenols in an immersion extractor. Effect of pulsing flow
Authors: Sineiro J. , Domínguez H. , Núñez M. J. , Lema J. M. 
Published: November 2006

AbstractA comparative study on polyphenol extraction from sunflower press cake in a semicontinuous pulsed‐flow immersion extractor and in a conventional laboratory immersion extractor was developed. The solvent was 96% (vol/vol) ethanol. No difference in the residual polyphenol content in the cake was observed at short times, but after 10 h, the pulsed extractor showed a higher polyphenol concentration in the outlet miscella. In addition, the effective diffusivity of polyphenols in sunflower press cake was estimated.
Supercritical carbon dioxide extraction of fatty and waxy material from rice bran
Authors: García A. , de Lucas A. , Rincón J. , Alvarez A. , Gracia I. , García M. A. 
Published: November 2006

AbstractWaxy and fatty materials were removed from rice bran by supercritical carbon dioxide at pressures up to 28 MPa and temperatures between 40 and 70°C. The yields of the supercritical extraction were only 16–60% of those obtained by Soxhlet extraction with hexane. The highest yield was reached at the highest pressure and temperature used (28 MPa and 70°C), indicating that supercritical extraction of this lipid‐bearing material could probably be improved at more severe extraction conditions. The supercritical extract obtained at operational conditions giving high yield was chromatographically characterized. Compared to the hexane extract, the supercritical extract was lighter in color and richer in wax content and long‐chain fatty acids C20−C34. Triacontanol was the most abundant alcohol in both extracts. Tocopherol contents were similar.
Methyl esters from a partially hydrogenated vegetable oil is a better infrared external standard than methyl elaidate for the measurement of totaltrans content
Authors: Ratnayake W. M. N. , Pelletier G. 
Published: November 2006

AbstractAn infrared spectrophotometric procedure, based on the fatty acid methyl ester mixture derived from a partially hydrogenated vegetable oil as the calibration standard, has been developed for accurate analysis of the totaltrans content of hydrogenated fats. This procedure produces more accurate results than the current official methods of Association of Official Analytical Chemists and American Oil Chemists’ Society, both of which use methyl elaidate as the external standard. The results obtained with this procedure were in close agreement to those determined by the combined procedure of silver‐nitrate thin‐layer chromatography and capillary gas‐liquid chromatography. The improved results, obtained with the partially hydrogenated vegetable oil methyl esters as the calibration standard, may be attributable to its assortment oftrans isomers, which may have different absorptivities relative to methyl elaidate.
Contribution of triglycerides from cocoa butter to the physical properties of milkfat fractions
Authors: Simoneau Catherine , German J. Bruce 
Published: November 2006

AbstractMilkfat was separated into major chainlength fractions by solid‐phase extraction. The effect on thermal behavior and texture of replacing both saturated and monounsaturated long‐chain triglycerides from milkfat by long‐chain monounsaturated triglycerides with an unsaturated fatty acid in thesn‐2 position is reported. Increasing proportions of cocoa butter were added to fractions of short‐to medium‐chain triglycerides (C22−C44) and medium‐ to long‐chain triglycerides (C36−C48) isolated from milkfat. Thermal behavior and texture of the mixtures were measured. Results indicated that long‐chain monounsaturated triglycerides from cocoa butter enhanced co‐crystallization and co‐operative melting and did not induce polymorphic transitions upon crystallization and melting of the fractions. At 4°C, they acted as texture builder if present in proportions of more than 30%, whereas below this level, they acted as texture softeners. The effect of the long‐chain monounsaturated triglycerides on the texture of fractions that melt at low temperature could not be predicted from the proportion of solid fat at that temperature.
Rapid determination of the totaltrans content of neat hydrogenated oils by attenuated total reflection spectroscopy
Authors: Mossoba Magdi M. , Yurawecz Martin P. , McDonald Richard E. 
Published: November 2006

AbstractA Fourier transform infrared spectroscopy procedure is described for quantitating the levels of totalrans triglycerides or their fatty acid methyl ester derivatives in neat fats and oils. It requires either warming or no preparation of the laboratory sample, and about 5 min for spectroscopic measurement, band area integration, and calculation of thetrans content from a linear regression equation. To eliminate the strongly sloping background of the 966‐cm−1trans band, the single‐beam spectrum of thetrans‐containing fat is “ratioed” against that of an unhydrogenated oil or a reference material that contains onlycis double bonds. Thus, a symmetric absorption band on a horizontal background is obtained. The area under thetrans band can then be accurately integrated between the same limits, 990 and 945 cm−1, for alltrans levels investigated. To speed up the analysis, an attenuated total reflection liquid cell was used, into which oils, melted fats or their methyl esters were poured without weighing or quantitative dilution with the toxic and volatile carbon disulfide solvent. Thetrans levels determined by attenuated total reflection were closer to those found by capillary gas chromatography when the hydrogenated fat was measured against the corresponding unhydrogenated oil than when it was measured against acis reference material. Small differences were found betweentrans levels in hydrogenated fat test samples and the corresponding methyl ester derivatives (9.3 and 2.2% at about 2 and 41%trans, respectively). The lower limits of identification and quantitation were 0.2 and 1%, respectively.
13C nuclear magnetic resonance spectroscopic analysis of the triacylglycerol composition of some margarines
Authors: Lie Ken Jie Marcel S. F. , Lam C. C. , Pasha Mohammed Khysar , Stefenov Kamen L. , Marekov I. 
Published: November 2006

AbstractThe triacylglycerol fraction of three samples of margarine, namely “Flora” (Holland), “Kaliakra” (Bulgaria), and “Corona” (Holland), were studied by13C nuclear magnetic resonance spectroscopy. By examining the various carbon chemical shifts of the saturated and unsaturated carbon nuclei, “Flora” margarine was shown to contain a mixture of hydrogenated and unhydrogenated vegetable oils. This technique allowed all major acyl groups (saturated, oleate, linoleate, and linolenate) and minor acyl components [different positional isomers of long‐chain (E)‐ and (Z)‐monoenoic moieties, arising as by‐products during catalytic hydrogenation] to be identified. The amount of each fatty acid present in the margarine was also estimated from the relative intensities of the corresponding signals. “Kaliakra” margarine consisted of a blend of unhydrogenated natural fats and oils that contained saturated fatty acids, oleate, and linoleate. There were no signs in the spectrum of “Kaliakra” of any (E)‐isomers, nor signals associated with positional unsaturated acyl groups (other than oleate and linoleate). The sample of “Corona” margarine consisted of a mixture of hydrogenated and unhydrogenated vegetable oils and butter (1.3%). The presence of butter in this sample was identified by the characteristic carbon shifts of the C‐1 to C‐4 carbon atoms of butyrate. The distribution of the fatty acids on the glycerol “backbone” also was estimated by this technique.
Interference of polar lipids with the alkalimetric determination of free fatty acid in fish lipids
Authors: Zhou Shengying , Ackman Robert G. 
Published: November 2006

AbstractAn examination of the suitability of an alkalimetric method for the determination of free fatty acid (FFA) contents in fats, oils, and lipid extracts was conducted by comparing AOCS method Ca 5a‐40 with a method based on a Chromarod‐latroscan thin‐layer chromatography‐flame‐ionization detector (TLC‐FID) system. The FFA contents determined by the alkalimetric method were consistently higher than the genuine FFA contents obtained by the latroscan TLC‐FID method. Phospholipids were found to be the major components that contributed to the alkali‐titratable, nongenuine FFA in the total FFA determined alkalimetrically. Contributions from other polar lipid components were smaller, but they dominated as the proportion of phospholipids fell. The other alkali‐titratable polar components may include oxidized lipids and their by‐products bound to protein fragments. The accurate determination of FFA contents by alkalimetric methods may only be applicable to those commercially refined fats and oils that contain negligible amounts of phospholipids. Corrections for the alkalimetrically determined FFA contents should be made for those fats and oils with relatively high phospholipid contents by correlating the nongenuine FFA contents and the phospholipid contents.
Alkali‐modified soy proteins: Effect of salts and disulfide bond cleavage on adhesion and viscosity
Authors: Kalapathy U. , Hettiarachchy N. S. , Myers D. , Rhee K. C. 
Published: November 2006

AbstractSoy protein isolates were treated with NaCl, Na2SO4, or Na2SO3 (disulfide bond‐cleaving agent) at a pH of 10.0 and 50°C, and the effects of these salts on viscosity, adhesive strength on woods, and water resistance of the treated isolates were investigated. Viscosity and adhesive strength decreased with increasing concentrations of these salts. At a concentration of 0.1 M, these three salts reduced the viscosity of soy proteins with no significant adverse effects on adhesive strength and water resistance. Addition of 0.1 M NaCl, Na2SO4, or Na2SO3 reduced adhesive strength insignificantly from 1230 N to 1120, 1060, or 1013 N, respectively. The viscosity of protein isolate modified at pH 10.0 and 50°C in the absence of salts was >30,000 cP. Treatment with NaCl or Na2SO4 resulted in viscosity reductions to 6000 or 1050 cP, respectively. The Na2SO3 treatment yielded an isolate with the lowest viscosity of 110 cP and which retained adhesive and water‐resistive properties. The water resistance of modified soy proteins with and without 0.1 M Na2SO3 treatment was not significantly different with 3.3 and 6.6% cumulative delaminations occurring after four water soaking cycles. Treatment with 0.1 M Na2SO3 resulted in an isolate with a 28% decrease in disulfide linkages.