bluuebunny/crossref_metadata_2025_split huggingface dataset:
Collaborative test of determination of iodine value in fish oils. 1. Reaction time and carbon tetrachloride or cyclohexane as solvents
Authors: Barlow Stuart M. , Bimbo Anthony P. , Miller Eric L. , Thorisson Snorri , Walters D. E. 
Published: May 2007

AbstractTwenty‐two laboratories participated in a collaborative test to determine the iodine value (IV) of eight samples of fish oil (four with IV<150, four with IV>150) with either carbon tetrachloride (AOCS Official Method Cd 1–25) or cyclohexane (AOCS Recommended Practice Cd 1b‐87) as solvent and either 1 or 2 h of reaction time. Laboratories received coded duplicate samples (hidden duplicates) and carried out duplicate determinations on each oil by each solvent‐time combination (open duplicates). Replacing carbon tetrachloride with cyclohexane resulted in a lower IV (P<0.001). The decrease averaged 1.6 IV units for low‐IV oils and 3.8 IV units for high‐IV oils; this difference in response of 2.2 IV units between low‐ and high‐IV oils was significant (P<0.001). Increasing the reaction time had a relatively small effect (0.34±0.18). There was no interaction of reaction time with solvent or oil type. Cyclohexane caused emulsions, which made it difficult to titrate residual iodine and thus increased the variability of the determination. The repeatability standard deviations (sr), based on hidden duplicates, for 1‐h reaction time with carbon tetrachloride and cyclohexane were 2.17 and 3.35, respectively. The corresponding reproducibility standard deviations were 2.73 and 4.53.
An original transesterification route for fatty acid ester production from vegetable oils in a solvent‐free system
Authors: Goma‐Doncescu N. , Legoy M. D. 
Published: May 2007

AbstractWax ester production from a long‐chain alcohol and methyl ester has been investigated with an immobilized thermostable lipase (lipozyme IM from Novo Nordisk). The transesterification reaction rate was monitored in solvent‐free medium that was exclusively composed of the reactants and the enzyme. The transesterification is performed by simply mixing the two substrates in various stoichiometric amounts at a temperature range from 55 to 65°C under constant stirring in the presence of low concentrations of enzyme preparation (0.12 to 2%, w/w). Long‐chain reactants produce waxes of high molecular mass that induce low solubility and high viscosity. On average, high transesterification yields are obtained (around 95%). Thermodynamic parameters involving substrate concentration and temperature have also been investigated. The balance between optimal working temperature and the molar ratio of substrates in such a complex medium appears to be 60°C, with a molar ratio methyl oleate/stearyl alcohol of 1:0.5. Substrate inhibition due to stearyl alcohol has been observed. A study of kinetic parameters has confirmed these results.
Seasonal changes in the lipid classes and fatty acid compositions of hake (Merluccius hubbsi) liver oil
Authors: Méndez Eduardo 
Published: May 2007

AbstractThe lipid content, lipid class composition, and fatty acid composition of hake (Merluccius hubbsi) liver oil was studied for a whole year. The lipid content of the liver ranged from 41 to 60%. Triacylglycerols were the main lipid class present in the oil, with a mean value of 80%. Docosahexaenoic acid was the main polyunsaturated fatty acid during the year and was twice that of the eicosapentaenoic acid content. The composition of hake liver oil makes it useful as a raw material for encapsulated pharmaceutical products.
Catalytic hydrogenation of linoleic acid over platinum‐group metals supported on alumina
Authors: Kitayama Yoshie , Muraoka Masahiro , Takahashi Megumi , Kodama Tatsuya , Takahashi Eriko , Okamura Mutsuo 
Published: May 2007

AbstractCatalytic activity and selectivity for hydrogenation of linoleic acid (cis‐9,cis‐12 18:2) were studied on Pt, Pd, Ru, and Ir supported on Al2O3. Stearic acid (18:0) and 10 different octadecenoic isomers (18:1) in the products could be separated completely by using a new capillary column coated by isocyanopropyl trisilphenylene siloxane for gas‐liquid chromatography. The monoenoic acid isomers and dienoic acid isomers in the products on the various catalysts showed different distributions. The catalysts exhibited nearly equal selectivity for stearic acid formation. The 12‐position double bond in linoleic acid has higher reactivity than the 9‐position double bond in catalytic hydrogenation on platinum‐group metal catalysts. In addition to hydrogenation products of linoleic acid, geometrical and positional dienoic acid isomers (trans‐9,trans‐12; trans‐8,cis‐12; cis‐9,trans‐13; trans‐9,cis‐13; cis‐9,trans‐12 18:2), due to isomerization of linoleic acid during hydrogenation, were contained in the reaction products. Ru/Al2O3 exhibited the highest activity for isomerization of linoleic acid with the noble metal catalysts. Conjugated octadecadienoic acid isomers have been observed in products of the reaction on Pt/Al2O3, Ru/Al2O3, and Ir/Al2O3. Catalytic activities of noble metals for positional and geometric isomerization of linoleic acid during hydrogenation decreased in the sequence of Ru ≥ Pt > Ir » Pd.
Effect of chlorine dioxide treatment on lipid oxidation and fatty acid composition in salmon and red grouper fillets
Authors: Kim Jeongmok , Lee Yangsoon , O’Keefe Sean F. , Wei Cheng‐i 
Published: May 2007

AbstractChlorine dioxide (CIO2) has been explored as a potential substitute for aqueous chlorine to clean seafood products. In an attempt to understand the interaction of CIO2 with organic compounds, duplicate fillets of Atlantic salmon (Salmo salar) and red grouper (Epinephelus morio) were treated for 5 min with freshly prepared aqueous CIO2 at 20, 40, 100, and 200 ppm total available CIO2 in 3.5% brine. Thiobarbituric acid (TBA) values and fatty acid composition were determined. CIO2‐treated salmon and red grouper showed a dose‐related increase in TBA; the 100 and 200 ppm groups had significantly (P<0.05) greater TBA values than controls and the 20 ppm group. Treated red grouper and salmon did not differ in percentage monounsaturated and polyunsaturated fatty acids compared to controls, although differences occurred with some individual fatty acids. Thus, CIO2 treatment did not greatly affect fatty acid composition of treated fillets.
Effects of selected substrate forms on the synthesis of structured lipids by two immobilized lipases
Authors: Lee Ki‐Teak , Akoh Casimir C. 
Published: May 2007

AbstractTwo immobilized lipases, IM 60 from Rhizomucor miehei and SP 435 from Candida antarctica, were used to synthesize structured lipids (SL). Tricaprin and trilinolein were interesterified to produce SL that contained one linoleic acid per triacylglycerol molecule (SL1) and SL with two linoleic acids (SL2). SL1 and SL2 were separated by silver nitrate thin‐layer chromatography according to their unsaturation, and the fatty acid at the sn‐2 position was determined after pancreatic lipasecatalyzed hydrolysis of SL1 and SL2. With IM 60, 57.7 mol% capric acid and 42.3 mol% linoleic acid were found at the sn‐2 position of SL1, while 43.3 mol% capric acid and 56.7 mol% linoleic acid were at the sn‐2 position of SL2. The fatty acid at the sn‐2 position of SL1 with SP 435 as biocatalyst was 43.6 mol% capric acid and 56.4 mol% linoleic acid, while SL2 contained 56.6 mol% capric acid and 43.4 mol% linoleic acid. Different structural forms of the capric acid‐containing substrate (triacylglycerol vs. ethyl ester) and different chainlengths of triacylglycerol were selected to study the substrate selectivity of lipases. Results indicated that SP 435 had some degree of preference for the triacylglycerol form (tricaprin), and IM 60 produced SL more rapidly and reached steady state faster with tricaprin as substrate than with capric acid ethyl ester. For chainlength selectivity, mol% of synthesized SL from tricaprin + trilinolein and tristearin + trilinolein were compared. SP 435 exhibited no apparent preference for either tricaprin or tristearin. However, IM 60 showed a more rapid reaction with tricaprin than with tristearin.
Synthesis of oligoethylene glycol ethers from the seed oil of Vernonia anthelmintica
Authors: Singh Sukhprit 
Published: May 2007

AbstractThe seed oil of Vernonia anthelmintica on reaction with diols (mono‐, di‐, tri‐, or tetraethylene glycols) in the presence of boron trifluoride etherate, followed by saponification and esterification (methanol/H+), gives the oligoethylene glycol ethers: methyl 12(13)‐hydroxy‐13(12) [2‐hydroxy‐ethyl‐1‐oxy]‐octadec‐9‐enoate; methyl 12(13)‐hydroxy‐13(12)‐[5‐hydroxy‐3‐oxapentyl‐1‐oxy]‐octadec‐9‐enoate; methyl 12(13)‐hydroxy‐13(12)‐[8‐hydroxy‐3,6‐dioxaoctyl‐1‐oxy]‐octadec‐9‐enoate; and methyl 12(13)‐hydroxy‐13(12)‐[11‐hydroxy‐3,6,9‐trioxaundecyl‐1‐oxy]‐octadec‐9‐enoate. Methyl 12,13‐dihydroxyoctadec‐9‐enoate is a co‐product in all reactions.
Design of a single‐stage mechanical fat separator
Authors: Onwulata C. I. , Goldberg N. 
Published: May 2007

AbstractThermal fractionation of highly saturated fats can address the current nutritional concerns related to the amount, type, and saturated‐fat level of lipids in foods. Separation of fats into different melting fractions allows for tailoring natural fats into functional and nutritional groups, while also allowing for the use of the less desirable fractions in nonfood applications. The single‐stage laboratory‐scale separator described herein separates fats into two gross melting fractions, termed high and low. The latter fractions can be further separated by adjusting the cooling zone temperatures, resulting in secondary fractions with different melt patterns. Thermal analysis of the hard fractions shows a 10–15°C shift to a higher melting point.
α‐Melt‐mediated crystallization of 1‐palmitoyl‐2‐oleoyl‐3‐stearoyl‐sn‐glycerol
Authors: Rousset Ph. , Rappaz M. 
Published: May 2007

AbstractThe α‐melt‐mediated crystallization of 1‐palmitoyl‐2‐oleoyl‐3‐stearoyl‐sn‐glycerol (POS) has been investigated by differential scanning calorimetry (DSC), combined with polarized‐light microscopy. Starting from a completely liquid state, the melt was first cooled down and maintained at a temperature, T1, during a time, t1, where the α‐phase formed. Then it was heated to a temperature, T2, above the melting point of α for isothermal solidification into a solid phase, which was identified as δ. Based upon DSC solidification peaks, the time‐temperature‐transformation (TTT) diagram of POS was constructed for these solidification conditions and was compared with the TTT diagram of direct crystallization from the melt. The α‐melt‐mediated solidification showed accelerated kinetics of the δ‐phase. The effects of T1 and t1 were also studied: at short t1, crystallization was faster with a decreasing value of T1, whereas the opposite trend was observed for a longer plateau at T1. These tendencies were interpreted in terms of three competing phenomena: the density of δ‐nuclei that can form during the plateau at T1, α‐δ solid‐state transformation, and memory effects of molecule arrangements in the α‐remelted phase.
Enrichment of lesquerolic and auricolic acids from hydrolyzed Lesquerella fendleri and L. gordonii oil by crystallization
Authors: Frykman Hans B. , Isbell Terry A. 
Published: May 2007

AbstractLesquerolic and auricolic acids were obtained from hydrolyzed lesquerella oil by a low‐temperature crystallization procedure. The lesquerolic and auricolic fatty acid fraction was enriched from 55–59% to 85–99% with high yields (94%). Washing the free fatty acids with pH 6.0 buffer provided reproducible crystallizations of those hydroxy fatty acids. In contrast, when hydrolyzed oil from Lesquerella fendleri was not buffer‐washed, there was, in most cases, no separation of hydroxy fatty acids by crystallization. This crystallization procedure is suitable for a large‐scale separation process of the hydroxy fatty acids from nonhydroxy fatty acids obtained from hydrolyzed lesquerella oil.
On‐line chemical database for new crop seeds
Authors: Abbott T. P. , Phillips B. S. , Butterfield R. O. , Isbell T. A. , Kleiman R. 
Published: May 2007

AbstractSince the 1950s, a database of the chemical composition of seeds, collected throughout the world, has been generated at the National Center for Agricultural Utilization Research. Information contained in the database is primarily selected chemical and physical properties of seed oils. Over more than 38 years, 15,738 accessions of 7,924 species of 2,339 genera from 225 families were collected and analyzed. This database is now accessible on the Internet at http://www.ncaur.usda.gov/nc/ncdb/search.html.ssi. This paper gives an overview of the database, describes the information available, and illustrates how to do searches.
Chain‐breaking fused heterocyclic antioxidants: Antioxidant activities of 9H‐xanthene‐2,7‐diols and α‐tocopherol upon liposomal membranes
Authors: Yamamura Tatsuo , Ishida Takafumi , Tatara Hiroyuki , Nishiyama Tomihiro 
Published: May 2007

AbstractWe evaluated the antioxidant activities of 9H‐xanthene‐2,7‐diols and α‐tocopherol (α‐Toc) upon the oxidation of soybean phosphatidylcholine liposomal membranes, induced by 2,2′‐azobis(2‐amidinopropane) dihydrochloride (AAPH) and 2,2′‐azobis(2,4‐dimethylvaleronitrile (AMVN). The stoichiometric factors of 9H‐xanthene‐2,7‐diols, initiated with water‐soluble AAPH and lipid‐soluble AMVN, were 1.9–2.7 and 1.2–1.8‐fold greater than those of α‐Toc, respectively. The consumption profile of the antioxidant confirmed that 9H‐xanthene‐2,7‐diol was completely consumed within the induction period (tinh) and that the 9H‐xanthene‐2,7‐diol oxidation product was formed. When all oxidation product was depleted, tinh was terminated, and rapid oxidation occurred. These results suggested that the antioxidant activities of 9H‐xanthene‐2,7‐diol depend not only on the initial hydrogen abstraction from 9H‐xanthene‐2,7‐diol but also on a second hydrogen abstraction from the residual phenolic OH group of the oxidation product. Ascorbic acid (AsA) could not scavenge the radicals by itself in the lipid bilayer. However, when 9H‐xanthene‐2,7‐diol was located in the lipid bilayer, the addition of AsA into the aqueous phase prolonged tinh and reduced the rate of decay of 9H‐xanthene‐2,7‐diol.
Interactions between volatiles and lipids in complex systems
Authors: Le Thanh M. , Goubet I. , Le Quere J. L. , Voilley A. 
Published: May 2007

AbstractPartition equilibria of three aroma compounds in three different biphasic systems were studied by a liquid/liquid partition technique to investigate interactions that occur between volatiles and lipids in biphasic solutions. The lipids used were linoleic acid and ricinoleic acid and tetradecane as a model. The three aroma compounds were ethyl acetate, 2,5‐dimethylpyrazine, and oct‐1‐en‐3‐ol. The results showed that the intermolecular forces involved were weak. Infrared spectroscopy was then performed on binary systems (tetradecane and linoleic acid or aroma compound) and on ternary systems (tetradecane, linoleic acid, and aroma compound) to determine the nature of the interactions. This method confirmed the presence of hydrogen bonds between linoleic acid and 2,5‐dimethylpyrazine or oct‐1‐en‐3‐ol and also between molecules of oct‐1‐en‐3‐ol when the latter are present at high concentrations in lipids. The observations provided sufficient information to explain the behavior of oct‐1‐en‐3‐ol in biphasic solutions, but further work is needed to fully elucidate the nature of interactions between ethyl acetate or 2,5‐dimethylpyrazine and lipids and also to explain the behavior of these compounds in biphasic solutions.
Adhesion of edible oils to food contact surfaces
Authors: Michalski Marie‐Caroline , Desobry Stéphane , Pons Marie‐Noëlle , Hardy Joël 
Published: May 2007

AbstractAdhesion of oils and fatty food products to packages is an important storage problem, because it increases product‐package interactions that alter quality. Reducing such adhesion would also allow savings in recycling and cleaning processes. The aim of our work was to test if some thermodynamical adhesion models were correlated to edible oils’ bulk adhesion as measured experimentally. Food‐contact surfaces were low‐density polyethylene, polyethylene teraphthalate, stainless steel, and glass. The Young‐Dupré equation and five models of adhesion from the literature were used to calculate solids’ surface tension and the thermodynamical work of adhesion (Wa). The dispersive, polar, acid‐base, and hydrogen surface tension components of oils and solids were calculated. The experimental adhesion, or amount of edible oils remaining on solid surfaces after contact, was found to be correlated to Young‐Dupré Wa, involving contact angle measured by specially designed image analysis technique. Two models, involving, respectively, surface tension’s hydrogen component and a linear dependence of Wap on the liquid polar surface tension component, fitted best with oil bulk adhesion as measured experimentally. Our theoretical approach to fatty food material adhesion seems, so far, consistent to predict global residues of edible oils on solid surfaces.
A comparative study of methods for diagnosis of obesity in an urban mixed-race population in Minas Gerais, Brazil
Authors: de Freitas Silvia Nascimento , Caiaffa Waleska Teixeira , César Cibele Comini , Cândido Ana Paula Carlos , Faria Valéria Andrade , Neto Raimundo Marques do Nascimento , Machado-Coelho George Luiz Lins 
Published: May 2007

AbstractBackgroundObesity is defined as an excess of total body fat and may be assessed by different methods. The objective of the present study was to establish the discriminatory power of anthropometric data in determining obesity.MethodsThe subjects comprised 685 individuals, aged 20–79 years, sampled from a population-based survey. The following indicators were used: body mass index (BMI), waist circumference (WC) and total body fat percentage estimated with both Siri's equation (%BF Siri) and foot-to-foot bioelectrical impedance analysis (%BF BIA). Sensitivity and specificity of different cut-off points for each method were determined using %BF BIA as reference.ResultsOf 685 participants, 57.6% were aged ≥ 40 years, 69.9% were women and 72.6% self-referred themselves as non-white. To classify obesity based on sex and age among women aged < 40 years, the cut-off points were BMI of 26.0 kg m− 2, WC of 84.0 cm and %BF Siri of 34.0%; in those aged ≥ 40 years, the cut-off points were 28.0 kg m− 2, 90.0 cm and 37.4%, respectively. The cut-off points among men aged < 40 years were BMI of 26.3 kg m− 2, WC of 86.0 cm and %BF Siri of 22.5%, and in those aged ≥ 40 years, 26.3 kg m− 2, 89.0 cm and 24.5%, respectively. BMI was the method with the largest area under the curve (AUC) independent of sex and sex/age, yet no differences were observed in AUC between BMI and WC (P>0.05). Classifying according to skin colour did not change cut-off points in any indicator.ConclusionBMI and WC better discriminate obesity among women and men aged ≥ 40 years from a mixed-race population.
A‐272651, a nonpeptidic blocker of large‐conductance Ca2+‐activated K+channels, modulates bladder smooth muscle contractility and neuronal action potentials
Authors: Shieh C‐C , Turner S C , Zhang X‐F , Milicic I , Parihar A , Jinkerson T , Wilkins J , Buckner S A , Gopalakrishnan M 
Published: May 2007

Background and Purpose:The large‐conductance Ca2+‐activated K+channel (BKCa, KCa1.1) links membrane excitability with intracellular Ca2+signaling and plays important roles in smooth muscle contraction, neuronal firing, and neuroendocrine secretion. This study reports the characterization of a novel BKCachannel blocker, 2,4‐dimethoxy‐N‐naphthalen‐2‐yl‐benzamide (A‐272651).Experimental Approach:86Rb+efflux in HEK‐293 cells expressing BKCawas measured. Effects of A‐272651 on BKCaα‐ and BKCaαβ1‐mediated currents were evaluated by patch‐clamp. Effects on contractility were assessed using low‐frequency electrical field stimulated pig detrusor and spontaneously contracting guinea pig detrusor. Effects of A‐272651 on neuronal activity were determined in rat small diameter dorsal root ganglia (DRG).Key Results:A‐272651 (10 μM) inhibited86Rb+efflux evoked by NS‐1608 in HEK‐293 cells expressing BKCacurrents. A‐272651 concentration‐dependently inhibited BKCacurrents with IC50values of 4.59 μM (Hill coefficient 1.04, measured at +40 mV), and 2.82 μM (Hill coefficient 0.89), respectively, for BKCaα and BKCaαβ1‐mediated currents. Like iberiotoxin, A‐272651 enhanced field stimulated twitch responses in pig detrusor and spontaneous contractions in guinea pig detrusor with EC50values of 4.05±0.05 and 37.95±0.12 μM, respectively. In capsaicin‐sensitive DRG neurons, application of A‐272651 increased action potential firing and prolonged action potential duration.Conclusions and Implications:These data demonstrate that A‐272651 modulates smooth muscle contractility and neuronal firing properties. Unlike previously reported peptide BKCablockers, A‐272651 represents one of the first small molecule BKCachannel blockers that could serve as a useful tool for further characterization of BKCachannels in physiological and pathological states.British Journal of Pharmacology(2007)151, 798–806; doi:10.1038/sj.bjp.0707278
Tree Gibbs Sampler: identifying conserved motifs without aligning orthologous sequences
Authors: Cai Xiaohui , Hu Haiyan , Li Xiaoman Shawn 
Published: June 2007

AbstractSummary: Tree Gibbs Sampler is a software for identifying motifs by simultaneously using the motif overrepresentation property and the motif evolutionary conservation property. It identifies motifs without depending on pre-aligned orthologous sequences, which makes it useful for the extraction of regulatory elements in multiple genomes of both closely related and distant species.Availability: The Tree Gibbs Sampler software is freely downloadable at https://compbio.iupui.edu/xiaomanli/LiSoftware/retrieve.php?ID=tgsContact: shawnli@iupui.edu
Logistic regression for disease classification using microarray data: model selection in a largepand smallncase
Authors: Liao J.G. , Chin Khew-Voon 
Published: June 2007

AbstractMotivation: Logistic regression is a standard method for building prediction models for a binary outcome and has been extended for disease classification with microarray data by many authors. A feature (gene) selection step, however, must be added to penalized logistic modeling due to a large number of genes and a small number of subjects. Model selection for this two-step approach requires new statistical tools because prediction error estimation ignoring the feature selection step can be severely downward biased. Generic methods such as cross-validation and non-parametric bootstrap can be very ineffective due to the big variability in the prediction error estimate.Results: We propose a parametric bootstrap model for more accurate estimation of the prediction error that is tailored to the microarray data by borrowing from the extensive research in identifying differentially expressed genes, especially the local false discovery rate. The proposed method provides guidance on the two critical issues in model selection: the number of genes to include in the model and the optimal shrinkage for the penalized logistic regression. We show that selecting more than 20 genes usually helps little in further reducing the prediction error. Application to Golub's leukemia data and our own cervical cancer data leads to highly accurate prediction models.Availability: R library GeneLogit at http://geocities.com/jg_liaoContact: jl544@drexel.edu