bluuebunny/crossref_metadata_2025_split huggingface dataset:
Spectral confirmation of trans monounsaturated C18 fatty acid positional isomers
Authors: Mossoba M. M. , McDonald R. E. , Roach J. A. G. , Fingerhut D. D. , Yurawecz M. P. , Sehat N. 
Published: May 2007

AbstractThe trans octadecenoic acid methyl ester isomers were obtained from a partially hydrogenated soybean oil sample and isolated by silver‐ion high‐performance liquid chromatography. The double bond configuration was confirmed to be trans by using gas chromatography‐direct deposition‐Fourier transform infrared spectroscopy. The double bond positions for nine individual trans octadecenoic acid positional isomers were confirmed by gas chromatography‐electron ionization mass spectrometry after derivatization to 2‐alkenyl‐4,4‐dimethyloxazoline. These nine trans positional isomers were resolved on either one of the two polar 100% cyanopropylpolysiloxane 100‐m capillary columns, SP 2560 and Cp‐Sil 88, at an isothermal temperature of 140°C. These nine isomers were confirmed to have double bonds at carbons C‐8 through C‐16. The pair of trans octadecenoic acid positional isomers with double bonds at C‐13 and C‐14 are reported for the first time to be resolved by gas chromatography.
Simplified gravimetric determination of total fat in food composites after chloroform‐methanol extraction
Authors: Phillips Katherine M. , Tarragó‐Trani Maria Teresa , Grove Tina M. , Grün Ingolf , Lugogo Rita , Harris Robert F. , Stewart Kent K. 
Published: May 2007

AbstractA modification of Association of Official Analytical Chemists (AOAC) method 983.23 for the quantitative determination of total lipid in food composites was evaluated for the measurement of total fat. The procedure is based on the Bligh and Dyer chloroform/methanol total lipid extraction. Relative to AOAC 983.23, the proposed method is less labor‐intensive and is applicable to batch analysis of a larger number of samples, thus reducing the cost of analysis and increasing sample throughput. Total lipid values from the proposed method are comparable to those from AOAC 983.23 and slightly higher than total fat determined by acid hydrolysis (AOAC 954.02, 945.44, or 922.06). Recoveries of standard additions of different food‐grade oils from a mixed food composite were essentially quantitative, ranging from 96 to 101%. Total lipid measured in Total Diet Standard Reference Material 1548 (SRM 1548, National Institute of Standards and Technology) was 101% of the certified mean total fat content and within the certified range. The method is to be suitable for analysis of food composites with between 0.15 and 1.5 g total fat (3 to 30% by weight). More than 600 samples of a variety of total diet composites were collected and assayed as diet quality control samples for two National Heart, Lung and Blood Institute‐sponsored multicenter clinical feeding trials: DELTA (Dietary Effects on Lipoproteins and Thrombogenic Activity) and DASH (Dietary Approaches to Stop Hypertension). The mean coefficient of variation was 1.2% for duplicate assays of these samples over the course of two years and multiple analysts. In addition, total lipid values for more than 200 samples of a diet composite quality control material, used in this laboratory over a two‐year period, had a 3.99% coefficient of variation. Although the accuracy of all gravimetric total fat methods with respect to the U.S. Food and Drug Administration’s Nutritional Labeling and Education Act (NLEA) definition of total fat as the sum of triglycerides remains to be determined, the reported modification of AOAC 983.23 yields a total fat content of acceptable accuracy relative to other gravimetric methods, and with proper quality control the method has excellent precision.
Endogenous antioxidants and stability of sesame oil as affected by processing and storage
Authors: Shahidi F. , Amarowicz R. , Abou‐Gharbia H. A. , Shehata A. Adel Y. 
Published: May 2007

AbstractThe effect of processing of coated and dehulled sesame seeds on the content of endogenous antioxidants, namely sesamin, sesamolin, and γ‐tocopherol in hexane‐extracted oils, was studied over 35 d of storage under Schaal oven test conditions at 65°C. Seeds examined were Egyptian coated (EC) and dehulled (ED) and Sudanese coated (SC) varieties. Processing conditions of raw (RW) seeds included roasting at 200°C for 20 min (R), steaming at 100°C for 20 min (S), roasting at 200°C for 15 min plus steaming for 7 min (RS) and microwaving at 2450 MHz for 15 min (M). The sesamin content in fresh oils from EC, ED, and SC raw seeds was 649, 610, and 580 mg/100 g oil, respectively. Corresponding values for the content of sesamolin in oils tested were 183, 168 and 349 mg/100 g oil, respectively. Meanwhile, the content of γ‐tocopherol, the only tocopherol present in the oils, ranged from 330 to 387 mg/kg sample. The effect of processing on changes in the sesamin content in oils from coated seeds was low and generally did not exceed 20% of the original values. On the other hand, oils from dehulled seeds underwent a more pronounced decrease in their sesamin content than the oil from coated seeds after 35 d of storage at 65°C. The corresponding changes in sesamolin and γ‐tocopherol contents were more drastic. The RS treatment, which would be the optimal to prepare sesame oil with better quality, was found to retain 86, 80 and 60% of the sesamin, sesamolin and γ‐tocopherol, respectively, originally present in the seeds after the storage period. The loss in the content of endogenous antioxidants present in the oils paralleled an increase in their hexanal content.
Soybean‐lecithin supplementation of practical diets for juvenile goldfish (Carassius auratus)
Authors: Lochmann Rebecca , Brown Ramone 
Published: May 2007

AbstractSoybean lecithin, alone or in combination with cod liver or soybean oil, was tested as a supplemental lipid in practical diets for juvenile (0.3 g) goldfish (Carassius auratus). Goldfish were fed one of five diets containing: (i) 4% cod liver oil (CLO); (ii) 2% CLO+2% lecithin (LEC); (iii) 4% soybean oil (SBO); (iv) 2% SBO+2% LEC; (v) 4% LEC. After 6 wk, weight gain and feed efficiency of fish fed diets with 4% LEC were significantly higher than those of fish fed diets with 4% CLO or SBO. Gain and feed efficiency of fish fed diets with combinations of LEC and CLO or SBO were intermediate. Survival and whole‐body lipid were unaffected by diet. Possible mechanisms of performance enhancement in goldfish fed LEC include provision of myoinositol or phosphatidylcholine to support rapid membrane proliferation, enhanced absorption of dietary lipid, and facilitation of lipid transport.
A highly regioselective synthesis of δ‐lactones from meadowfoam fatty acids
Authors: Isbell Terry A. , Plattner Beth A. 
Published: May 2007

AbstractMeadowfoam fatty acids, when treated with mineral acid catalysts in the presence of polar nonparticipating solvents, undergo a facile ring closure to form δ‐lactones. Perchloric and sulfuric acids catalyze the cyclization at concentrations of 0.6–13 mole equivalents, both neat and in the presence of solvent. Under constant acid concentrations, methylene chloride was found to increase the rate of reaction, the regioselectivity for the formation of δ‐lactone, and the overall yield. In the absence of solvent, increased acid concentration improved the yield of lactone but reduced regioselectivity for the δ‐isomer. Solvent polarity plays a significant role in the regioselectivity of the cyclization for δ‐lactone, with solvents of higher dielectric strength providing larger δ/γ ratios (38:1) and higher yields up to 92%.
Genetic regulation of linolenic acid concentration in wild soybean Glycine soja accessions
Authors: Pantalone V. R. , Rebetzke G. J. , Burton J. W. , Wilson R. F. 
Published: May 2007

AbstractSoybean [Glycine max (L.) Merr.] oil from current commercial cultivars typically contains ca. 8% linolenic acid. Inheritance studies have shown that linolenic acid concentration in soybean seed is determined by at least two genes which govern activity of the predominant ω‐6 and ω‐3 desaturases. Selection of germplasm exhibiting homozygous recessive alleles that encode these desaturases has enabled development of soybeans having less than 3.0% linolenic acid. However, accessions of the wild ancestor of modern soybean cultivars, Glycine soja (Sieb. and Zucc.), have oils containing twice the highest linolenic acid concentration found in normal G. max cultivars. Although little is known about inheritance of linolenic acid in wild soybean, it would appear that additional or alternative forms of genes may govern its synthesis. To test this hypothesis, cultivated soybean germplasm was hybridized with wild soybean genotypes having significant differences in linolenic acid concentration. Seed of F3 progeny from these G. max x G. soja populations exhibited distinct segregation patterns for relative estimates of ω‐6 and ω‐3 desaturase activity. Frequency class distribution analyses of the segregation patterns, and linear relations between median ω‐6 or ω‐3 desaturation estimates and corresponding linolenic acid concentration among allelic classes from these populations suggested the high‐linolenic acid trait in wild soybean genotypes was determined by a set of desaturase alleles that were different from corresponding alleles in G. max. Introgression of these alternative alleles in G. max germplasm opens a new avenue of research on the genitic regulation of linolenic acid, and may lead to the production of highly polyunsaturated soybean oils for various industrial applications.
Positional distribution of Δ5‐acids in triacylglycerols from conifer seeds as determined by partial chemical cleavage
Authors: Blaise Pierre , Tropini Veronique , Farines Marie , Wolff Robert L. 
Published: May 2007

AbstractThe positional distribution of various Δ5‐acids in the seed triacylglycerols from several conifer species has been established after partial chemical degradation with Grignard reagent. The species studied were representative of four conifer families and were specially selected for their particularly high Δ5‐acid contents. These species were Taxus baccata (Taxaceae; 5,9‐18:2 acid, 11.9%), Larix decidua (Pinaceae; 5,9,12‐18:3 acid, 28.5%), Sciadopytis verticillata (Taxodiaceae; 5,11,14‐20:3 acid, 16.7%), and Juniperus communis (Cupressaceae; 5,11,14,17‐20:4 acid, 19.8%). Calculations from the fatty acid compositions of triacylglycerols and of the mixture of 1,2‐ and 2,3‐diacylglycerols generated by the Grignard reagent indicated that, for the four species, there was a considerable enrichment of Δ5‐acids (generally more than ten times) in the 1,3‐positions as compared to the 2‐position, where Δ5‐acids represented always less than 2% of total fatty acids esterified to triacylglycerols. This distribution was practically independent from the species (four families studied), the chainlength (18 or 20 carbon atoms), and the number of ethylenic bonds (two to four) in the Δ5‐acids. Similar distributions were established for triacylglycerols from the seeds of three pine species that are available on a ton‐scale: Pinus pinea, P. koraiensis, and P. pinaster. These observations confirm and extend previous studies conducted with other conifer species by similar techniques or by 13C‐nuclear magnetic resonance spectroscopy. Consequently, the almost exclusive location of Δ5‐acids in the external positions of triacylglycerols is now well established and appears to be a general feature of conifer seed oils.
The effect of partial glycerides on trilaurin crystallization
Authors: Smith Paul R. , Povey Malcolm J. W. 
Published: May 2007

AbstractThe effects of partial glycerides of fatty acid chainlength from C10 to C18 on trilaurin crystal growth rate were investigated. Glycerides of particular form were found to have similar effects. Free fatty acids or monoglycerides either had little effect or slightly increased growth rates, whereas diglycerides, especially 1,3‐diglycerides reduced them. If a particular glyceride has shorter chainlengths than trilaurin, the inhibition of crystallization is extremely small. For slightly longer chainlengths, a significant reduction of crystallization rate is seen, although smaller than with the addition of partial laurates. Maximum inhibition occurs with chainlength matching, and the magnitude decreases with increasing difference between host and guest chainlength.
Lipase‐catalyzed incorporation of oleic acid into melon seed oil
Authors: Moussata Charment O. , Akoh Casimir C. 
Published: May 2007

AbstractThe ability of lipase PS30 (Pseudomonas sp.) to modify the fatty acid profile of melon seed oil by incorporation of oleic acid (18:1n‐9) was investigated. The transesterification was carried out in hexane in an orbital shaking water bath at 55°C for 24 h with methyl oleate (70% pure) as acyl donor. Oleic acid content increased from 13.5% to 53%, and linoleic acid (18:2n‐6) content decreased from 65% to 33%. The incorporation of oleic acid into melon seed oil by Pseudomonas sp. lipase helped balance the fatty acid profile of the oil in terms of monounsaturated (18:1n‐9) and essential fatty acids (18:2n‐6).
Photoautotrophic cultivation of the green alga Chlamydomonas reinhardtii as a method for carbon dioxide fixation and α‐linolenic acid production
Authors: Akimoto Masamichi , Yamada Hidenao , Ohtaguchi Kazuhisa , Koide Kozo 
Published: May 2007

AbstractFocusing on CO2 fixation and α‐linolenic acid (ALA) production, photoautotrophic cultivation of the green alga Chlamydomonas reinhardtii was investigated by using a culture medium of pH 6.8 under a 5 vol% CO2‐enriched atmosphere. The optimum cultivation temperature and light intensity for growth were 25°C and 12 klux, respectively. The cellular ALA content nearly doubled to 11.9 mg/g of dry cells when the concentration of culture medium was doubled. Simulation of chemostat cultivation showed that the rate of CO2 fixation and ALA productivity per unit volume of culture medium could reach 1.01 kg CO2/(m3 · d) and 7.46 g ALA/(m3 · d), respectively, at a cell concentration of 0.57 kg cells/m3.
Peroxisomal changes during hiberation of jerboa (Jaculus orientalis)
Authors: Kabine M. , Cherkaoui‐Malki M , Clémencet C. ‐C. , El Kebbaj M. S. , Latruffe N. 
Published: May 2007

AbstractAs a member of the order of Rodentia, jerboa (Jaculus orientalis) is a natural deep hibernator and lives in subdesert highland in many parts of the world, including Morocco. Its small size (adult body weight ∼100 g), availability in the wild, tolerance to laboratory conditions, and some unique peroxisomal properties make it a suitable research subject for exploring peroxisome biogenesis under prehibernating and hibernating states. During 3 w, animals referred to as the prehibernator group were exposed to cold temperature (5 to 7°C) with food ad libitum. Part of the prehibernator group entered deep hibernation 24 to 48 h after starvation. Animals were sacrificed 4 and 6 d after starting hibernation. As a control, a third group, consisting of active animals, was maintained at 22°C. Concerning hibernation, results from plasma analysis showed an increased level for both ketonemia and ureamia, while triglyceredemia was decreased. Liver acyl‐CoA oxidase activity, a peroxisomal b‐oxidation enzyme, increased during hibernation. Liver peroxisomal urate oxidase was induced only during the prehibernating state and remained at an increased level until the fourth day of hibernation. The variations were concomitant to a decrease in peroxisomal protein yield and a differential change in peroxisomal protein pattern in sodium dodecyl sulfate‐polyacrylamide gel electrophoresis during prehibernating or hibernating states. These preliminary results show that cold exposure and hibernation affect biogenesis of liver peroxisomes in jerboa.
Analysis of sn‐1(3)‐ and sn‐2‐short‐chain acyl isomers of triacylglycerols in butteroil by gas‐liquid chromatography
Authors: Kemppinen Asmo , Kalo Paavo 
Published: May 2007

AbstractThe aim of the study was to determine major triacylglycerols (TG), and sn‐1(3) and sn‐2 isomers of butyryl and caproyl TG in butteroil (BO) and interesterified butteroil (IBO) by gas‐liquid chromatography (GLC) and silver ion column chromatography. Altogether, 112 molecular species of TG were synthesized by interesterification and their retention indices were determined. Molar empirical correction factors for TG were determined using linear calibration. Retention indices showed that sn‐1(3) and sn‐2 isomers of the TG containing one short‐chain acyl (butyrate, caproate) and two long‐chain acyls (lauroate, myristate, palmitate, stearate, and oleate) were separated on a phenyl (65%) methylsilicone column. The difference between retention indices of 1(3)‐ and 2‐short‐chain acyl isomers ranged from 14 to 19, and from 9 to 16 for butyrates and caproates, respectively. The proportion of sn‐2 isomers of butyrates averaged 1.4%, but only traces of sn‐2 isomers of caproates were detected in butteroil. The ratio of sn‐1(3)‐ to sn‐2‐butyrates and caproates in interesterified butteroil averaged 2.0:1. The most abundant molecular species of mono‐short‐chain TG in butteroil were BPP + BMS (5.6 mol%), BPO + BSPo (4.8 mol%), BMP + BLaS (3.4 mol%), BMO + BPPo (2.7 mol%), BPS (2.5 mol%), and CoPP + CoMS (2.3 mol%).
Gas chromatography‐fourier transform infrared spectrometry of fatty acids: New applications with a direct deposition interface
Authors: Sémon E. , Ferary S. , Auger J. , Le Quéré J. L. 
Published: May 2007

AbstractInfrared spectroscopy is a suitable spectroscopic method to differentiate geometric Z and E isomers of unsaturated compounds. A direct‐deposition Fourier transform infrared spectrometer (FTIR), coupled to a gas chromatograph, was used successfully to analyze with a high sensitivity traces of C18:1 fatty acid methyl ester (FAME) isomers. It could also conclusively distinguish between isomers of conjugated diunsaturated FAME. The achievable sensitivity of this direct‐deposition device makes possible accurate FAME mixture analyses that are not currently attainable with the more conventional light‐pipe interface.
Determination of sterols, oxysterols, and fatty acids of phospholipids in cells and lipoproteins: A one‐sample method
Authors: Blache D. , Durand P. , Girodon F. , Gesquière L. , Loreau N. 
Published: May 2007

AbstractIn addition to fatty acids, especially polyunsaturated species, cholesterol oxidizes and leads to various oxygenated derivatives, named oxysterols. They display a wide range of adverse biological properties. Monitoring oxysterols is important in the evaluation of the potential risks associated with lipid oxidation. In the present study, a quick and reliable method was developed for analysis of oxysterols, sterols, and fatty acid composition of phospholipids in the same biological sample. Total lipid extraction was determined after addition of several internal standards (epicoprostanol for sterols, 19‐hydroxy‐cholesterol for oxysterol and di‐heptadecanoyl‐phosphatidylcholine for phospholipid fatty acids). Cold acetone‐mediated precipitation was then used to fractionate sterols from phospholipids. The phospholipid‐containing precipitate was transmethylated for fatty acid analysis by gas chromatography. The sterol‐ and oxysterol‐containing phase was saponified under mild conditions to avoid artificial oxysterol generation and was analyzed by gas chromatography after derivatization into trimethylsilyl ethers. The overall procedure was found to be specific with good recovery and reproducibility for sterols, oxysterols [mean coefficient of variation in percent (CV), 11.3%] as well as phospholipid fatty acids (CV, 5.6%). This procedure has been used to document in vitro free radical treated‐human low‐density lipoproteins and erythrocytes. Results demonstrated that this method is a useful tool in assessing qualitative and quantitative differences in oxysterols and phospholipid fatty acid patterns attributed to lipid oxidation.
Determination of low trans levels in refined oils by fourier transform infrared spectroscopy
Authors: De Greyt W. , Kint A. , Kellens M. , Huyghebaert A. 
Published: May 2007

AbstractA Nicolet 410 Fourier (FTIR) spectrophotometer, equipped with a DGTS detector and a sample cell with NaCl windows (nominal pathlength=50 μm), was used for the development of an FTIR method for routine analysis of low trans levels in physically refined oils. The approach of the study differed from those previously described in that a separate calibration curve was established for each type of oil. Quantitation was established by use of Basic Quant Software® and by measuring the peak height at 967 cm−1 relative to a baseline drawn between 1002 and 932 cm−1. The slope of the different calibration curves established in six vegetable oils (soybean, corn, sunflower, high‐oleic sunflower, low‐erucic rapeseed, and high‐erucic rapeseed) was close to 1 (0.9942–1.0041), and correlation coefficients (r2) were rather good (0.9990–0.9999). FTIR spectra of 20 soybean oil samples were collected and quantitated with the different calibrations. Compared to previous reported literature data, increased accuracy (mean difference=0.05%; standard deviation of difference=0.11%) and reproducibility (r2=0.09–0.12%) were obtained when the FTIR spectra were quantitated with a calibration curve based on 10 physically refined soybean oil samples.
Applications of chromatographic techniques to evaluate enzymatic hydrolysis of oxidized and polymeric triglycerides by pancreatic lipase in vitro
Authors: Márquez‐Ruiz G. , Guevel G. , Dobarganes M. C. 
Published: May 2007

AbstractWith the aim of studying the susceptibility to enzymatic hydrolysis of oxidized and polymeric triglycerides (TG) that are formed during frying, various chromatographic techniques were applied in combination, i.e., adsorption chromatography, high‐performance size‐exclusion chromatography (HPSEC), and thin‐layer chromatography‐flame ionization detection (TLC‐FID). Polar fractions, isolated by adsorption chromatography from thermoxidized trilinolein as model system, and real used frying fats and oils, were analyzed by HPSEC before and after incubation with pancreatic lipase in vitro. Also, the influence of degradation level of used frying oils on hydrolysis of intact TG was investigated with the additional aid of TLC‐FID. Results showed the high hydrolysis rate of oxidized TG monomers in contrast to the significant discrimination of pancreatic lipase against TG dimers and, particularly, TG polymers. On the other hand, hydrolysis of intact TG can be affected by the presence of dimers and polymers in abused frying oils.
Application of headspace analysis to the study of aroma compounds‐lipids interactions
Authors: Druaux C. , Le Thanh M. , Seuvre A. ‐M. , Voilley A. 
Published: May 2007

AbstractTaking into account interactions between aroma compounds and food components is necessary to better manage the flavoring of food products. These interactions occur at a molecular level and reflect changes, at a macroscopic level, in thermodynamic equilibria, such as solubility or volatility. The rate of transfer of an aroma compound from the liquid to the vapor phase can be affected as well. The behavior of aroma compounds in water and lipid solutions was studied in two complementary ways, a thermodynamic and a kinetic approach (head‐space analysis). The transfer rate of volatiles at the liquid‐water interface does not only depend on the hydrophobicity of the aroma compounds. Vapor‐liquid partition and activity coefficients show the presence of solute‐solvent interactions. The Gibbs free energy values indicate their physicochemical nature.