bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ethenolysis of esters of vegetable oils: Effect of B2O3 addition to Re2O7/SiO2.Al2O3‐SnBu4 and CH3ReO3/SiO2.Al2O3 metathesis catalysts
Authors: Mandelli Dalmo , Jannini Marcelo J. D. M. , Buffon Regina , Schuchardt Ulf 
Published: November 2006

AbstractImpregnation of SiO2.Al2O3 (24.3% Al2O3 with 6% B2O3 increases the activity of supported Re2O7 in the ethenolysis of methyl oleate, but reduces the activity of CH3ReO3 on the same support. Re2O7/SiO2.Al2O3/B2O3‐SnBu4 is shown to be an effective catalyst for the ethenolysis of methyl linoleate and of the methyl esters of olive oil, and can be recycled after calcination at least five times without loss of activity.
Comparison of the structural and functional effects of monomeric and dimeric human apolipoprotein A‐II in high density lipoprotein particles
Authors: Lund‐Katz Sissel , Murley Yvette M. , Yon Errol , Gillotte Kristin L. , Davidson W. Sean 
Published: November 2006

AbstractHigh density lipoprotein (HDL) is throught to play a significant role in the process of reverse cholesterol transport. It has become clear that the apolipoprotein (apo) composition of HDL is important in determining the metabolic fate of this particle. The major proteins of human HDL are apoAI and APOAII; the latter protein is a disulfide‐linked dimer in humans and higher primates but monomeric in the other species. The consequences of the apo Cys6‐Cys6 disulfide bridge in apoAII for human HDL structure and function are not known. To address this issue, the influence of the Cys6‐Cys6 disulfide bridge on the interaction of human apoAII with palmitoyl‐oleoyl phosphatidylcholine has been studied. The size and valence of a series of homogeneous discoidal complexes containing either monomeric (reduced and carboxymethylated) or dimeric apoAII have been determined, and their ability to remove cholesterol from rat Fu5AH hepatoma cells grown in culture has been compared. The apoAII dimer and monomer form discoidal complexes of similar size, with twice as many of the latter molecule required per disc. Removal of the disulfide bond influences the stability of the helical segments around the edge of the disc as seen by a decrease in α‐helix content of the monomeric protein. The discoidal particles containing the monomeric form of apoAII are somewhat more effective than particles containing either dimeric apoAII or apoAI in removing cellular cholesterol. Overall, reduction of the disulfide bridge of apoAII probably does not have a major effect in the determination of HDL particle sizein vivo. It follows that the evolution of the Cys6‐Cys6 disulfide bond in higher primates probably has not had a major effect on the function of the apoAII molecule.
Kinetics of formation of fluorescent products from hexanal andl‐lysine in a two‐phase system
Authors: Stapelfeldt Henrik , Skibsted Leif H. 
Published: November 2006

AbstractKinetics of formation of fluorescent condensation products from hexanal andl‐lysine (or itsN‐acetylated forms) including mass‐transfer has been studied in a two‐phase system consisting of lysine (or lysine derivative) in a aqueous phosphate buffer and a 1‐octanol solution of hexanal as model for formation of fluorophores between protein and carbonyl compounds in peroxidizing biological systems. The initial rate of formation of fluorescent products in the aqueous phase was found to be proportional to the concentration of hexanal and lysine and to increase in both phases with increasing pH in the aqueous phase, in contrast to a higher‐order dependence on hexanal in the octanol phase. At pH=6.8, the temperature dependence of the appearance of fluorescent products corresponds to apparent energies of activation of 63 kJ·mol−1 and 87 kj·mol−1 in the aqueous phase and the octanol phase, respectively. Fluorescent condensation products appeared faster in the octanol phase. However, by a kinetic analysis, the fluorescent products were shown to be formed in the aqueous phase, corresponding to the lower energy of activation and to the simple second‐order kinetics, and subsequently distributed between the aqueous phase and the octanol phase.l‐Lysine reacted faster thanNα‐acetyl‐l‐lysine which reacted faster thanNε‐acetyl‐l‐lysine. Using fluorescence quantum yields, determined to be 1.4·10−2 in octanol and 8·10−3 in water at pH 6.8, an apparent partition coefficient of 17 (octanol/water) was determined for the condensation product ofl‐lysine. The steady‐state fluorescence in the octanol phase was attributed to two components with fluorescence life‐time at 25°C of 0.7±0.05 ns and 5.1±0.2 ns, assigned to hexanal and the condensation product, respectively. The emission spectra, were resolved in the two components using phase‐sensitive detection, and the condensation product had emission maximum at 405 nm.
Hydrolysis of used frying palm olein and sunflower oil catalyzed by porcine pancreatic lipase
Authors: Arroyo R. , Sánchez‐Muniz F. J. , Cuesta C. , Burguillo F. J. , Sánchez‐Montero J. M. 
Published: November 2006

AbstractThe enzymatic hydrolysis of frying used vegetable oils with different degrees of alteration were measured using porcine pancreatic lipase (acylglycerol acylhydrolase EC 3.1.1.3). Successive frying of potatoes significantly increased the level of total polar lipid content in the palm olein from 9.3±0.1 mg/100 mg oil to 26.4±0.3 mg/100 mg oil after 90 fryings, and from 4.0±0.1 mg/100 mg oil to 27.7±0.3 mg/100 mg oil in sunflower oil after 60 fryings. Triacylglycerol polymers, triacylglycerol dimers, and oxidized triacylglycerols also increased 37‐, 7.9‐, and 7.5‐times in palm olein, respectively, and 56‐, 22‐, and 4.7‐times in sunflower oil, respectively. However, diacylglycerols and free fatty acid levels related to hydrolytic alteration did not increase with the number of fryings in both oils. The substrate concentration in the reactor was determined by calculating the molecular weight of each oil showing a different degree of alteration. We compared the methodology used by us and that used by other authors. The results show that the methods are reproducible and that the values obtained are in concordance with theoretical values. The kinetic parameters apparent Michaelis‐Menten constant (KMapp) and apparent maximum velocity of hydrolysis (Vmaxapp) were different in unused palm olein (5.1±0.7 and 166±7.6, respectively) than in sunflower oil (2.2±0.3 and 62±2.2, respectively). However, changes inKMapp andVmaxapp were not related to the degree of alteration of the oils.
Chronic free fatty acid infusion in rats results in insulin resistance but no alteration in insulin‐responsive glucose transporter levels in skeletal muscle
Authors: Magnan C. , Gilbert M. , Kahn B. B. 
Published: November 2006

AbstractTo investigate the mechanism by which free fatty acids (FFA) affect glucose uptake, we studied the effect of chronic elevation (24 h) of plasma FFA in rats on whole body glucose disposal and glucose utilization index (GUI) in the basal state and under a euglycemic hyperinsulinemic clamp in relation to the amount of insulin‐responsive glucose transporter (IRGT, i.e., GLUTU), protein in different muscles (oxidative and glycolytic) and adipose tissue. Infusion of Intralipid in the basal state led to a∼40% increase in whole body glucose uptake and a∼250% increase in GUI in adipose tissue as compared to control rats. There was no change in the amount of IRGT protein in any of the muscle types whereas in fat depots it was either unchanged or decreased. Under moderate or supraphysiological hyperinsulinemia, increment of whole body glucose disposal was significantly lower in Intralipid perfused rats when compared to controls (∼110 μU/mL: 0.7±0.1 vs. 1.3±0.1 mg/min,P<0.02; ∼1000 μU/mL: 3.0±0.2 vs. 3.9±0.4 mg/min,P<0.02). Under moderate hyperinsulinemia stimulation, GUI was significantly reduced in different muscles and adipose tissue as compared to controls. We conclude that peripheral insulin resistance which occurs after elevation of plasma FFA levels does not seem to be explained by changes in the amount of IRGT protein in either oxidative or glycolytic skeletal muscle. Thus fatty acid infusion appears to be associated with a defect in IRGT translocation to the plasma membrane, fusion with the membrane, or intrinsic activity.
Highly hydrogenated dietary soybean oil modifies the responses to polychlorinated biphenyls in rats
Authors: Kamei Masaharu , Ohgaki Sumiko , Kanbe Tamotsu , Shimizu Mitsuru , Morita Shigeru , Niiya Isao , Matsui‐Yuasa Isao , Otani Shuzo 
Published: November 2006

AbstractThe effects of dietary highly hydrogenated soybean oil (HSO) upon the changes caused by dietary polychlorinated biphenyls (PCBs) were examined in rats. Six groups of rats were fed the following diets for 30 d: a 20% soybean oil‐containing diet (control diet), a diet in which a half of soybean oil was substituted with HSO (HSO‐A diet), a diet in which cellulose powder was replaced with HSO (HSO‐B diet) and these diets supplemented with 100 ppm PCBs (control+PCBs, HSO‐A+PCBs and HSO‐B+PCBs diets). Hepatic concentration of PCBs and relative liver weight were markedly decreased in rats fed with the HSO‐A+PCBs diet compared with those fed with the other diets containing PCBs. Liver lipids and liver cholesterol were considerably decreased with a reciprocal increase in fecal sterol excretion by rats fed the HSO‐A+PCBs and the HSO‐B+PCBs diets compared with those fed with the control+PCBs diet. The fatty acid composition in hepatic phospholipids showed an independent increase of the saturated fatty acid content induced by dietary HSO and PCBs. Dietary PCBs also caused decreases in the amounts of monounsaturated and n‐3 polyunsaturated fatty acids. These results suggest that dietary HSO prevents accumulation of PCBs in the liver and promotes the excretion of lipids stimulated by PCBs, accompanied by a change in fatty acid metabolism.
Modification of membrane fatty acid composition, eicosanoid production, and phospholipase a activity in Atlantic Salmon (Salmo salar) gill and kidney by dietary lipid
Authors: Bell J. Gordon , Farndale Bruce M. , Dick James R. , Sargent John R. 
Published: November 2006

AbstractAtlantic salmon post‐smolts were fed diets containing either fish oils (Fosol, FO and Marinol, MO) rich in long‐chain n‐3 polyunsaturated fatty acids (PUFA), or plant oils rich in 18:2n‐6 (sunflower oil, SO) or 18:3n‐3 (linseed oil, LO) for 12 wk. The major PUFA in individual phospholipids from gill and kidney were related to the dietary lipid intake. Levels of n‐6 PUFA were highest while levels of n‐3 PUFA were lowest in fish fed SO. Fish fed LO generally had lower levels of 20:4n‐6 compared to the other treatments while fish fed SO generally had the highest levels of 20:4n‐6. In all phospholipid classes except phosphatidylinositol (PI) 20:5n‐3 was greatest in fish fed MO followed by FO, LO, and SO. In PI, 20:5n‐3 was also highest in fish fed MO but those fed LO contained more 20:5n‐3 than those fed FO. This resulted in the ratio of the eicosanoid precursors, 20:4n‐6/20:5n‐3, being significantly greater in fish fed SO, for all phospholipid classes, compared to fish fed the other three dietary oils. The activity of gill phospholipase A was greatest in fish fed FO and was lowest in fish fed SO. The concentration of PGF3α was significantly increased in gill homogenates from fish fed MO compared to the other three treatments while PGF2α was significantly increased in fish fed SO compared to those fed LO. The concentration of PGE3 was significantly reduced in kidney homogenates from fish fed SO compared to the other three treatments while PGE2 was significantly increased in fish fed SO compared to those fed either FO or LO.
Effect of sample storage on quantitation of lipoprotein (a) by an enzyme‐linked immunosorbent assay
Authors: Evans Rhobert W. , Sankey Steadman S. , Hauth Beth A. , Sutton‐Tyrrell Kim , Kambon M. Ilyas , Kuller Lewis H. 
Published: November 2006

AbstractThis study evaluated the effect of storage on the quantitation of lipoprotein (Lp)(a) in 25 serum samples. Aliquots of serum were stored for up to three years at either −20°C or−70°C and Lp(a) subsequently analyzed using an enzyme‐linked immunosorbent assay kit. Concentrations of Lp(a) declined during storage, and the temperatures employed elicited significantly different (P<0.05) values within 12 mon which further diverged during three years of storage. Compared to baseline values, significant decreases (P<0.05) in Lp(a) levels were evident after six months of storage at−20°C with apparent losses (geometric mean) reaching 36.9% (95% confidence interval: 30.9%, 42.9%) after three years. Similarly, significantly lower (P<0.05) Lp(a) values were recorded after six months of storage at−70°C and at three years the decrease (geometric mean) was 19.1% (95% confidence interval: 14.3%, 24.0%). The losses, after three years, in terms of the arithmetic mean were 53.5 and 26.2% at−20 and−70°C, respectively. Phenotype analysis suggested that large isoforms are more susceptible to degradation than smaller moieties. This may be related to the observation that apparent losses are reduced in samples containing over 8 mg/dL Lp(a). Nevertheless, Lp(a) levels in stored samples retained a strong correlation with the baseline values. These results must be considered specific for the storage conditions and analytical procedures employed.
The sterols ofCucurbita moschata (“calabacita”) seed oil
Authors: Rodriguez Juan B. , Cros Eduardo G. , Bertoni Maria H. , Cattaneo Pedro 
Published: November 2006

AbstractFrom the sterol fraction of seed oil from commercialCucurbita moschata Dutch (“calabacita”) Δ5 and Δ7 sterols having saturated and unsaturated side chain were isolated by chromatographic procedures and characterized by spectroscopic (1H and13C‐nuclear magnetic resonance, mass spectrometry) methods. The main components were identified as 24S‐ethyl 5α‐cholesta‐7,22E‐dien‐3β‐ol (α‐spinasterol); 24S‐ethyl 5α‐cholesta‐7,22E, 25‐trien‐3β‐ol (25‐dehydrochondrillasterol); 24S‐ethyl 5α‐cholesta‐7, 25‐dien‐3β‐ol; 24R‐ethylcholesta‐7‐en‐3β‐ol (Δ7‐stigmastenol) and 24‐ethyl‐cholesta‐7, 24(28)‐dien‐3β‐ol (Δ7,24(28)‐stigmastadienol).Lipids 31, 1205–1208 (1996).
Real‐time X‐ray powder diffraction investigations on cocoa butter. II. The relationship between melting behavior and composition of β‐cocoa butter
Authors: van Malssen Kees , Peschar René , Schenk Henk 
Published: November 2006

AbstractThe melting behavior of twelve different cocoa butter samples, in the β‐phase, has been investigated with real‐time X‐ray powder diffraction. The melting trajectory of each sample is characterized by three temperature values: a starting point, a point of maximum melting, and a point of complete melting. These points are determined by an analysis of the subsequent X‐ray diffraction patterns. A least‐squares analysis has been developed which allows the observed melting points to be related to the composition of the cocoa butter. This analysis shows that the melting behavior of cocoa butter can be described as a function of certain binary combinations of its major components.
Real‐time X‐ray powder diffraction investigations on cocoa butter. III. Direct β‐crystallization of cocoa butter: Occurrence of a memory effect
Authors: van Malssen Kees , Peschar René , Brito Claudia , Schenk Henk 
Published: November 2006

AbstractDirect β‐crystallization of different samples of cocoa butter has been investigated. The influence of the thermal history of cocoa butter on its phase behavior is defined as a memory effect. The chemical composition of cocoa butter has been related to the occurrence of the short‐term β‐memory effectvia statistical analysis of the results. We explain how this effect can be attributed mainly to stearic acid and its related triacylglycerols. The total phase behavior of cocoa butter is discussed on the basis of the results obtained from the series of three papers of which this is the last.
Deacidification of black cumin seed oil by selective supercritical carbon dioxide extraction
Authors: Türkay Selma , Burford Mark D. , Kemal Sangün M. , Ekinci Ekrem , Bartle Keith D. , Clifford Anthony A. 
Published: November 2006

AbstractThe deacidification of high‐acidity oils from Black cumin seeds (Nigella sativa) was investigated with supercritical carbon dioxide at two temperatures (40 and 60°C), pressures (15 and 20 MPa) and polarities (pure CO2 and CO2/10% MeOH). For pure CO2 at a relatively low pressure (15 MPa) and relatively high temperature (60°C), the deacidification of a highacidity (37.7 wt% free fatty acid) oil to a low‐acidity (7.8 wt% free fatty acid) oil was achieved. The free fatty acids were quantitatively (90 wt%) extracted from the oil and left the majority (77 wt%) of the valuable neutral oils in the seed to be recovered at a later stage by using a higher extraction pressure. By reducing the extraction temperature to 40°C, increasing the extraction pressure to 20 MPa, or increasing the polarity of the supercritical fluid via the addition of a methanol modifier, the selectivity of the extraction was significantly reduced; the amount of neutral oil that co‐extracted with the free fatty acids was increased from 23 to 94 wt%.
Isolation of tocopherol and sterol concentrate from sunflower oil deodorizer distillate
Authors: Ghosh S. , Bhattacharyya D. K. 
Published: November 2006

AbstractThe isolation of tocopherols and sterols together as a concentrate from sunflower oil deodorizer distillate was investigated. The sunflower oil deodorizer distillate was composed of 24.9% unsaponifiable matter with 4.8% tocopherols and 9.7% sterols, 28.8% free fatty acid (FFA) and 46.3% neutral glycerides. The isolation technology included process steps such as biohydrolysis, bioesterification and fractional distillation. The neutral glycerides of the deodorizer distillates were hydrolyzed byCandida cylindracea lipase. The total fatty acids (initial FFA plus FFA from neutral glycerides) were converted into butyl esters withMucor miehei lipase. The esterified product was then fractionally distilled in a Claisen‐vigreux flask. The first fraction, which was collected at 180–230°C at 1.00 mm of Hg for 45 min, contained mainly butyl esters, hydrocarbons, oxidized products and some amount of free fatty acids. The fraction collected at 230–260°C at 1.00 mm Hg for 15 min was rich in tocopherols (about 30%) and sterols (about 36%). The overall recovery of tocopherols and sterols after hydrolysis, esterification and distillation were around 70% and 42%, respectively, of the original content in sunflower oil deodorizer distillate.
Low‐molecular weight organic compositions of acid waters from vegetable oil soapstocks
Authors: Johansen Steven L. , Sivasothy Arunthathi , Dowd Michael K. , Reilly Peter J. , Hammond Earl G. 
Published: November 2006

AbstractAlkaline extracts (soapstocks) from canola, corn, cottonseed, peanut, soybean, and sunflower oil refining were acidified, and identities and concentrations of the low‐molecular weight organic components of the resulting acid waters were determined by gas chromatography, followed by mass spectroscopy, and by high‐performance liquid chromatography. The main components of each acid water sample, in order of decreasing concentration and after omitting the fermentation product lactic acid, were phosphoric acid, α‐glycerophosphate, and glycerol from canola;myo‐inositol, phosphoric acid, α‐glycerophosphate andmyo‐inositol‐1‐phosphate from corn; glycerol, α‐glycerophosphate,myo‐inositol‐1‐phosphate, and β‐glycerophosphate from cottonseed; phosphoric acid, glycerol, andmyo‐inositol from peanut; α‐glycerophospho‐1‐myo‐inositol,myo‐inositol‐1‐phosphate, α‐glycerophosphate, and glycerol from soybean; and α‐glycerophosphate, glycerol,myo‐inositol‐1‐phosphate, and β‐glycerophosphate from sunflower.
Determination of the identity of by‐products in the industrial production of saturated fatty acids
Authors: Skovly Joakim , Lundanes Elsa , Greibrokk Tyge 
Published: November 2006

AbstractA technical product of saturated fatty acids has been analyzed to determine the structure of by‐products found in the C20–22 fatty acids manufactured from fish oil. Short‐path distillation of the weakly colored product provided a residue, which was extracted either by supercritical carbon dioxide or by acetone. Extracts and residues were analyzed by size‐exclusion chromatography, supercritical fluid chromatography, and by gas chromatography, the latter combined with mass spectrometry and Fourier‐transform infrared spectroscopy, and by nuclear magnetic resonance spectrometry. A series of homologs of fatty acid dimers was identified as lactone esters. Each homolog also contained several isomers with a varying number of carbon atoms in the two hydrocarbon chains of the dimers. Trimers, containing yellow components, were also present in small amounts, but the structure of the trimers has not been determined yet.
Oxidative stabilities of soybean oils that lack lipoxygenases
Authors: Shen N. , Fehr W. , Johnson L. , White P. 
Published: November 2006

AbstractLipoxygenase (LOX)‐null soybean lines that lack LOX 2, or LOX 2 and 3, and contain normal (8.0–8.6%) or low (2.0–2.8%) linolenate (18∶3) amounts were evaluated for their oil qualities and storage stabilities. Soybean oils of six genotypes were extracted by both laboratory‐scale and pilot‐plant systems and were refined, bleached, and deodorized in the laboratory. Citric acid was added to oils during the cool‐down stage of deodorization. Two replications, separated at the point of conditioning, were evaluated for each genotype. Under storage conditions of 55–60°C in the dark, soybean oils with low 18∶3 contents were significantly (P<‐0.05) more stable as measured by peroxide values than were oils with normal 18∶3 contents, regardless of the LOX content of the beans. The volatile analysis showed few differences between oils with low and high 18∶3 contents or among oils from beans that lack different LOX enzymes. After 16 d of storage, the amount of 1‐octen‐3‐ol was significantly greater in oils with low 18∶3 content, and soybean oils from beans with normal LOX content had a significantly (P<‐0.05) lower amount of 1‐octen‐3‐ol than did the oils that lacked LOX enzymes. Storage at 35°C under light showed no differences in volatile amounts or sensory evaluations after 14 d of storage. During storage, peroxide values tended to be lower in oils from beans with normal 18∶3 content and in oils from beans with normal LOX content. Generally, the abscence of LOX 2 or LOX 2 and 3, although having a small effect on lipid oxidation, was not as important to oil quality as was the 18∶3 content.
Recent unrest at Canary Islands' Teide Volcano?
Authors: Carracedo Juan Carlos , Troll Valentin R. , Pérez Francisco J. , Badiola Eduardo Rodríguez , Machín Alex Hansen , Paris Raphael , Guillou Hervé , Scaillet Stéphane 
Published: November 2006

When a volcano that has been dormant for many centuries begins to show possible signs of reawakening, scientists and civil authorities rightly should be concerned about the possibility that the volcanic unrest might culminate in renewed eruptive activity. Such was the situation for Teide volcano, located on Tenerife in the Canary Islands, when a mild seismic swarm during April–July 2004 garnered much attention and caused public concern. However, that attention completely ignored the fact that the seismic recordings of the swarm were due to a much improved monitoring system rather than due to an actual event of alarming magnitude or extent.It is important in any effective program of volcano‐risk mitigation that the response to an apparent change in the status of a volcano should include the immediate implementation or augmentation of monitoring studies to better anticipate possible outcomes of the volcanic unrest. Equally important, emergency‐management officials, using available scientific information and judgment, must take appropriate precautionary measures—including information of the populations at potential risk—while not creating unjust anxiety or alarm.