bluuebunny/crossref_metadata_2025_split huggingface dataset:
Conjugated linoleic acid and oxidative stress
Authors: Banni Sebastiano , Angioni Elisabetta , Contini Maria Stefania , Carta Gianfranca , Casu Viviana , Iengo Giorgio Amedeo , Melis Maria Paola , Deiana Monica , Dessì Maria Assunta , Corongiu Francesco P. 
Published: May 2007

AbstractAt the present time, conjugated linoleic acid (CLA) is the subject of a growing number of studies since it has been demonstrated to possess anticarcinogenic and antiatherogenic activities in experimental animal models and to increase in some pathological states in humans. In both situations, CLA has been claimed to be involved in oxidative stress, as an antioxidant in the first case and as a primary product of a free‐radical attack on polyunsaturated fatty acids (PUFA) in the other. The controversial results are due mostly to a lack of a suitable methodology because the presence of conjugated dienes (CD) in lipid moiety has been taken for years as evidence of lipid peroxidation due to the occurrence of this structure in fatty acid hydroperoxides. We have recently developed a new methodology that consists of the extraction of fatty acids, including CD fatty acid hydroperoxides, by mild saponification and their separation and identification by high‐performance liquid chromatography with diode array detector. Fatty acid analyses of liver homogenate, oxidized in vitro either with Fe‐ADP or t‐butyl hydroperoxide (t‐ButylHP), of lamb and rats fed CLA at levels known to prevent carcinogenesis, showed that CLA and its metabolites steadily decreased during oxidative stress and that they are more prone to oxidation than their corresponding methylene‐interrupted fatty acids. No significant antioxidant effect of CLA was detected in any model tested. However, CD fatty acid hydroperoxides increased in the t‐ButylHP model but not in the Fe‐ADP model, owing probably to the degradation of CD fatty acid hydroperoxides induced by this oxidative agent. In conclusion, CLA and its metabolites seem to behave, under oxidative stress, as regular PUFA. Thus, it is highly unlikely that the peculiar effects of CLA are directly related to interference in lipoperoxidative processes.
Isolation of chemically induced mutants in borage (Borago officinalis L.)
Authors: De Haro‐Bailón A. , Del Rio M. 
Published: May 2007

Abstractγ‐Linolenic acid (GLA, 18:3 Δ6,9,12) has been reported to be helpful in the treatment of a wide range of disorders. Borage (Borago officinalis L.) is an annual plant of renewed interest because the seeds are an important source of GLA. The failure to retain mature seeds until harvest limits the total seed and GLA yield per plant and is the major limiting factor for the commercial production of borage. In the course of a mutagenesis program, an agronomically good line of white‐flowered borage (RG‐001) was treated with ethyl methane sulfonate. As a result of this program, several types of mutants were identified in the M2 generation of plants: a chlorotic mutant (type A); a mutant with increased number of sepals, petals, and ovules but reduced fertility (type B); and mutants with closed flowers (type C1) or partially opened flowers (type C2) that had increased seed retention. The type C mutants are the first reported borage plants with a nonshattering habit. After crossing type B plants with normal plants, a new mutant (type B1) was obtained with higher fertility and higher seed production per flower than those from normal plants. These mutants could be used to develop borage lines that would be superior to those currently available as a source of GLA.
Synthesis and physicochemical characterization of mixed diacid triglycerides that contain elaidic acid
Authors: Elisabettini P. , Lognay G. , Desmedt A. , Culot C. , Istasse N. , Deffense E. , Durant F. 
Published: May 2007

AbstractThe synthesis of symmetrical and asymmetrical palmito‐ and stearo‐elaidic triglycerides (PEP, SES, EPP, PEE, ESS, and SEE, in which P=palmitic, S=stearic, and E=elaidic acid) was undertaken to investigate their polymorphism. The chemical pathways and the purification steps, including crystallization and adsorption chromatography, are described. The different chromatographic analyses (gas‐liquid chromatography: carbon number profile and fatty acid methyl ester profile, and high‐performance liquid chromatography) revealed that the purity of the synthesized products was superior to 99% except for SES (>96%). The thermal behavior, as well as the polymorphism of these triglycerides, has been investigated by means of differential scanning calorimetry and powder X‐ray diffraction spectroscopy at variable temperatures. The six compounds crystallize according to a double chainlength packing. The most stable polymorphic form of palmito‐elaidic triglycerides belongs to the β′ variety, whereas the stearo‐elaidic triglycerides are β stable.
Total and partial erucate of pentaerythritol. Infrared spectroscopy study of relationship between structure, reactivity, and thermal properties
Authors: Eychenne Valérie , Mouloungui Zéphirin , Gaset Antoine 
Published: May 2007

AbstractEsters of neopentylpolyols are an important starting base for synthetic lubricants. These bulky esters are generally prepared by an esterification reaction between a carboxylic acid and a neopentylpolyol. Because neopentylpolyols have a number of primary alcohol sites, a variety of partial esters is formed before total esters. In the present study, we investigated the reaction between pentaerythritol and erucic acid. The composition of the reaction mixture in erucic acid, partial esters, and total esters was monitored by thin‐layer chromatography, coupled with flame‐ionization detection. The pure esters and the esters in solution at different concentrations in xylene at different temperatures were analyzed by Fourier transform infrared spectroscopy. Erucic acid and partial esters in xylene coexist in the free form and as bound complexes. These findings furthered understanding of the reactivity and thermal properties of the partial esters.
Pilot batch production of specific‐structured lipids by lipase‐catalyzed interesterification: Preliminary study on incorporation and acyl migration
Authors: Xu X. , Balchen S. , Høy C. ‐E. , Adler‐Nissen J. 
Published: May 2007

AbstractEffects of water content, reaction time, and their relationships in the production of two types of specific‐structured lipids (sn‐MLM‐ and sn‐LML‐types: L‐long chain fatty acids; M‐medium chain fatty acids) by lipase‐catalyzed interesterification in a solvent‐free system were studied. The biocatalyst used was Lipozyme IM (commercial immobilized lipase). The substrates used for sn‐MLM‐type were fish oil and capric acid, and medium chain triacylglycerols and sunflower free fatty acids for sn‐LML‐type. The observed incorporation with the time course agrees well with the Michaelis‐Menten equation, while the acyl migration is proportional to time within the range of 20 mol% acyl migration (MLM‐type: Mf=0.2225 T, R2=0.98; LML‐type: Mf=0.5618 T, R2=0.99). As water content (wt%, on the enzyme basis) increased from 3.0 to 11.6% for MLM‐type and from 3.0 to 7.2% for LML‐type in the solvent‐free systems, the incorporation rates in the first 5 h increased from 3.34 to 10.30%/h, and from 7.29 to 11.12%/h, respectively. However, the acyl migration rates also increased from 0.22 to 1.12%/h and from 0.56 to 1.37%/h, respectively. Different effects in the production of two totally position‐opposed lipids can be observed. Presumably these are caused by the different chain length of the fatty acids. The relationships between reaction time and water content are inverse and give a quantitative prediction of incorporation and acyl migration in selected reaction conditions and vice versa. The acyl migration can not be totally avoided in present systems, but can be reduced to a relatively low level. Acyl migration during the downstream processing has also been observed and other factors influencing the acyl migration are briefly discussed.
Efficient lipase‐catalyzed production of tailor‐made emulsifiers using solvent engineering coupled to extractive processing
Authors: Edmundo Castillo , Valérie Dossat , Didier Combes , Alain Marty 
Published: May 2007

AbstractWithin the framework of enzymatic biosurfactant synthesis, the development of reaction processes leading to a selective and efficient production is of crucial interest. In this work, we proposed an enzymatic method for producing 1(3)‐monooleoyl‐rac‐glycerol using a commercial immobilized lipase, the Lipozyme®. To avoid the blockage of the enzyme by the presence of insoluble glycerol, the latter was adsorbed onto dried silica gel. The selective monoester production (83%) was obtained using 2‐methyl‐2‐butanol amended n‐hexane (90:10, vol/vol) as reaction medium. The observed decrease in the substrate conversion, in a medium containing 2‐methyl‐2‐butanol, was countered by coupling to the reaction an inline selective recovery method for the produced monoester by adsorption onto a silica gel column located at the outflow of the reaction vessel. This process leads to an efficient monooleoyl glycerol production with a high oleic acid conversion (71%) and to the recovery of a 100% pure monooleoyl glycerol.
Cellulose esterification with fatty acids and acetic anhydride in lithium chloride/N,N‐dimethylacetamide medium
Authors: Vaca‐Garcia C. , Thiebaud S. , Borredon M. E. , Gozzelino G. 
Published: May 2007

AbstractHomogeneous esterification of cellulose with saturated fatty acids (n‐octanoic to n‐octadecanoic) was accomplished with acetic anhydride co‐reactant in lithium chloride/N,N‐dimethylacetamide (LiCl/DMAc) medium. Cellulose mixed triesters (CMT) were obtained after 5 h at 130°C with an average of 2.2 acetyl groups and 0.8 fatty substituents per anhydroglucose unit. A mixed acetic‐fatty anhydride, formed in situ, accounts for the grafting of the fatty moiety. The purified products were characterized and compared to the analogous cellulose simple fatty triesters (CST) that were synthesized from fatty acid chlorides in pyridine medium. Dynamic contact angle with water, glass transition, and storage moduli were correlated with the length of the fatty substituents. The CMT proved to be highly hydrophobic and more mechanically resistant than the CST.
Proteins from Crambe abyssinica oilseed. I. Isolation procedure
Authors: Massoura E. , Vereijken J. M. , Kolster P. , Derksen J. T. P. 
Published: May 2007

AbstractCrambe abyssinica is a promising new oil crop because of the specific properties of its oil. However, little information is available concerning the properties of the proteins, which constitute a major component of the seed. Therefore, a method for the isolation of proteins from Crambe seeds was developed. Protein extractability for whole and dehulled Crambe meal was studied as a function of pH. Highest extractability was obtained with dehulled meal at pH 11. Double extraction at this pH increased the extractability to about 66%. Protein precipitation from the above‐mentioned extract was studied as a function of pH with and without addition of a precipitating agent, i.e., carboxymethylcellulose (CMC). Addition of CMC resulted in a protein recovery of about 75% at pH 4.4. Without CMC, about half of the protein was recovered by isoelectric precipitation. The remaining soluble protein could be concentrated by ultrafiltration with a recovery of about 65%. The developed process, not including CMC addition, results in two protein fractions, i.e., an isoelectric precipitate (protein content 75%) and a retentate (protein content 87%), which together account for about 50% of the protein present in Crambe meal. Application of heat decreased protein extractability, but the protein contents of the resulting fractions were comparable to those from non‐heat‐treated meal.
Proteins from Crambe abyssinica oilseed. II. Biochemical and functional properties
Authors: Massoura E. , Vereijken J. M. , Kolster P. , Derksen J. T. P. 
Published: May 2007

AbstractLittle information is available concerning the properties of proteins that constitute a major component of the seed of Crambe abyssinica. Therefore, a method was developed to isolate these proteins. This procedure resulted in two fractions, an isoelectric precipitate (Fraction 1) and a retentate after ultrafiltration (Fraction 2). Biochemical and functional properties of both fractions were studied. Gel permeation chromatography revealed that high‐molecular‐weight proteins (>669,000 Da) are present only in Fraction 1, whereas Fraction 2 consists of proteins with lower molecular weights (<200,000 Da). Sodium dodecyl sulfate‐polyacrylamide gel electrophoresis, in the presence of mercaptoethanol, showed that both fractions consist of proteins that range mainly from 40,000 to less than 14,400 Da. Fraction 1 was highly soluble only at acid and alkaline pH values, while the solubility of Fraction 2 remained high (>80%) over the whole pH range tested. Addition of NaCl did not have any profound effect on the solubility of Fraction 2, but it increased significantly that of Fraction 1 in the isoelectric range. Foaming properties of Fraction 1 were better than those of chicken egg white only at pH 9, whereas those of Fraction 2 were superior at almost every pH value studied. Addition of NaCl improved significantly the foaming properties of Fraction 1 at all pH values tested but did not have a profound effect on the foaming properties of Fraction 2. Both fractions had good emulsifying properties only at alkaline pH values.
Analysis of conjugated linoleic acid isomers and content in french cheeses
Authors: Lavillonnière F. , Martin J. C. , Bougnoux P. , Sébédio J.‐L. 
Published: May 2007

AbstractConjugated linoleic acid (CLA) occurs in food as a result of microbial enzymatic reactions, free radical‐type oxidation, and heat treatment. CLA is found in animal products, such as meat and dairy products, especially in cheeses. The CLA composition of 12 different French cheeses was determined by a combination of different analytical methods: reversed‐phase high‐performance liquid chromatography (RP‐HPLC), gas chromatography‐mass spectrometry (GC‐MS), GC‐Fourier transform infrared (GC‐FTIR), and silver nitrate thin‐layer chromatography (AgNO3‐TLC). New isomers (Δ8,10‐ and Δ11,13‐octadecadienoic acids with all possible cis and trans configurations) that co‐eluted with previously identified isomers (Δ9c,11t‐; Δ9t,11c‐; Δ10c,12t‐; Δ10t,12c‐; Δ11c,13c‐; Δ9c,11c‐; Δ10c,12c‐; Δ9t,11t‐; Δ10t12t‐octadecadienoic acids) were detected. Δ9c,11t‐Octadecadienoic acid was the major CLA isomer in these cheeses. All isomers were present in each product, whatever the production process. However, CLA content in the cheeses varied from 5.3 to 15.80 mg/g of cheese fat, which depended primarily on the origin of the milk (season, geography) and somewhat on the production process.
Determination of trans fatty acids in hydrogenated vegetable oils by attenuated total reflection infrared spectroscopy: Two limited collaborative studies
Authors: Adam M. , Chew M. , Wasserman S. , McCollum A. , McDonald R. E. , Mossoba M. M. 
Published: May 2007

AbstractAn attenuated total reflection infrared spectroscopy procedure was collaboratively studied among two sets of five laboratories for quantitating the total trans fatty acid levels in neat (without solvent) hydrogenated vegetable oils, measured as triacylglycerols in one study, and as fatty acid methyl ester derivatives in the other. Unlike the fatty acid methyl esters, the triacylglycerols required no derivatization but had to be melted prior to measurement. To obtain a symmetric absorption band at 966 cm−1 on a horizontal background, the single‐beam spectrum of the trans‐containing fat was “ratioed” against that of a refined oil or a reference material that contained only cis double bonds. A single‐bounce horizontal attenuated total reflection cell that requires 50 µL of undiluted test samples was used for oils, melted fats, or their methyl esters. For fatty acid methyl esters, the reproducibility relative standard deviations were in the range of 0.9 to 18.46% for 39.08 to 3.41% trans, determined as methyl elaidate per total fatty acid methyl esters. For five pairs of triacylglycerol blind duplicates, the reproducibility and repeatability relative standard deviations were in the ranges of 1.62 to 18.97%, and 1.52 to 13.26%, respectively, for 39.12 to 1.95% trans, determined as trielaidin per total triacylglycerols. Six pairs of spiked triacylglycerol blind duplicates (quality assurance standards) exhibited high accuracy in the range of 0.53 to 40.69% trans and averaged a low bias of 1.3%. These statistical analysis results were compared to those collaboratively obtained by the recently adopted AOCS Cd14‐95 and AOAC 994.34 Infrared Official Methods.
CO2 laser infrared optothermal spectroscopy for quantitative adulteration studies in binary mixtures of extra‐virgin olive oil
Authors: Favier Jan Paul , Bicanic Dane , Cozijnsen Jan , van Veldhuizen Beb , Helander Per 
Published: May 2007

AbstractOptothermal window spectroscopy at CO2 laser infrared wavelengths was used to detect the extent of adulteration of extra‐virgin olive oil by sunflower and safflower oils. A good linearity between the strength of optothermal signal and the concentration of each adulterating compound was found. Predicted limits of detection presently attainable by this new method are 6 (w/w) and 4.5% (w/w) for extra‐virgin olive oil adulterated with safflower oil and sunflower oil, respectively, and were confirmed experimentally; the corresponding relative errors were 0.3 and 0.18%. Interference effects are comparable to those encountered in other spectroscopic methods at the same wavelength.
Rapid methods for predicting the appearance of turbidity in sunflower oil and their comparison with cold tests
Authors: Baltanás Miguel A. , Molina Hugo , Silva Carlos 
Published: May 2007

AbstractTwo rapid turbidimetric methods have been applied to determine the content of wax in refined and refined‐bleached sunflowerseed oils in the range of 0 to 120 ppm. Synthetic wax‐oil mixtures were prepared to construct calibration plots. Turbidimetric results were compared with visual evaluation of these mixtures as well as of the industrial oils by an expert panel, during 2 wk, under cold‐test (0°C) and tempering (15°C) conditions. Based on the standard AOCS cold‐test, the visual turbidity threshold of these Argentine oils was under 40 ppm, a value significantly lower than that found in European cultivars. Also, while both types of industrial oils passed the cold‐test, the refined oil developed cloudiness after tempering for 14 d, whereas the refined‐bleached oil remained transparent. Because the calibration plots showed that the turbidity difference values, given by these fast methods, corresponded to wax contents that caused visible turbidity but fell into the nonsensitive region of the instrument, a simple standard addition technique was used to extend their sensitivity to these low wax contents. With this improvement, oils that contained more than 40 ppm of wax by fast turbidimetry, which can be expected to develop cloudiness on storage in the winter season, can be promptly identified, thus allowing any desired corrective action.
Purity assessments of major vegetable oils based on δ13C values of individual fatty acids
Authors: Woodbury Simon E. , Evershed Richard P. , Barry Rossell J. 
Published: May 2007

AbstractThe fatty acid compositions and δ13C values of the major fatty acids of more than 150 vegetable oils were determined to provide a database of isotopic information for use in the authentication of commercial maize oil. After extraction of oils from seeds, nuts or kernels, and methylation, fatty acid compositions were determined by capillary gas chromatography. All compositions were within the ranges specified by the Codex Alimentarius. Gas chromatography combustion‐isotope ratio mass spectrometry was employed to determine the δ13C values of the major fatty acids of the oils. A large number of pure maize oils and potential adulterant oils from various parts of the world were studied to assess the sources of variability in δ13C values. Such information is vital to establishing the compound specific isotope technique as a reliable means of assessing vegetable oil purity. Variability in δ13C values was related to the geographical origin of the oil, year of harvest, and the particular variety of oil. This suggests that the ultimate δ13C values of fatty acids are determined by a combination of environmental and genetic factors.
Performance studies of various cracking catalysts in the conversion of canola oil to fuels and chemicals in a fluidized‐bed reactor
Authors: Katikaneni Sai P. R. , Adjaye John D. , Idem Raphael O. , Bakhshi Narendra N. 
Published: May 2007

AbstractStudies were conducted at atmospheric pressure at temperatures in the range of 400–500°C and fluidizing gas velocities in the range of 0.37–0.58 m/min (at standard temperature and pressure) to evaluate the performance of various cracking catalysts for canola oil conversion in a fluidized‐bed reactor. Results show that canola oil conversions were high (in the range of 78–98 wt%) and increased with an increase in both temperature and catalyst acid site density and with a decrease in fluidizing gas velocity. The product distribution mostly consisted of hydrocarbon gases in the C1–C5 range, a mixture of aromatic and aliphatic hydrocarbons in the organic liquid product (OLP) and coke. The yields of C4 hydrocarbons, aromatic hydrocarbons and C2–C4 olefins increased with both temperature and catalyst acid site density but decreased with an increase in fluidizing gas velocity. In contrast, the yields of aliphatic and C5 hydrocarbons followed trends completely opposite to those of C2–C4 olefins and aromatic hydrocarbons. A comparison of performance of the catalysts in a fluidized‐bed reactor with earlier work in a fixed‐bed reactor showed that selectivities for formation of both C5 and iso‐C4 hydrocarbons in a fluidized‐bed reactor were extremely high (maximum of 68.7 and 18 wt% of the gas product) as compared to maximum selectivities of 18 and 16 wt% of the gas product, respectively, in the fixed‐bed reactor. Also, selectivity for formation of gas products was higher for runs with the fluidized‐bed reactor than for those with the fixed‐bed reactor, whereas the selectivity for OLP was higher with the fixed‐bed reactor. Furthermore, both temperature and catalyst determined whether the fractions of aromatic hydrocarbons in the OLP were higher in the fluidized‐bed or fixed‐bed reactor.
Eicosapentaenoic acid and docosahexaenoic acid production potential of microalgae and their heterotrophic growth
Authors: Vazhappilly Rema , Chen Feng 
Published: May 2007

AbstractTwenty microalgal strains were investigated in photoautotrophic flask cultures for their potential for eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) production. The highest EPA proportion (% of total fatty acids) was produced by Monodus subterraneus UTEX 151 (34.2%), followed by Chlorella minutissima UTEX 2341 (31.3%) and Phaeodactylum tricornutum UTEX 642 (21.4%). The highest DHA proportion (% of total fatty acids) was obtained in Crypthecodinium cohnii UTEX L1649 (19.9%), followed by Amphidinium carterae UTEX LB 1002 (17.0%) and Thraustochytrium aureum ATCC 28211 (16.1%). Among the 20 strains screened, the EPA yield was high in M. subterraneus UTEX 151 (96.3 mg/L), P. tricornutum UTEX 642 (43.4 mg/L), Chl. minutissima UTEX 2341 (36.7 mg/L), and Por. cruentum UTEX 161 (17.9 mg/L) owing to their relatively high biomass concentrations. The DHA yield was high in C. cohnii UTEX L1649 (19.5 mg/L) and A. carterae UTEX LB 1002 (8.6 mg/L). Heterotrophic growth of these 20 microalgae was also tested on two different carbon sources, acetate and glucose. All microalgae except Nannochloropsis oculata UTEX LB 2164 showed growth on glucose (5 g/L) under heterotrophic conditions. Twelve of them could grow heterotrophically when acetate (1 g/L) was used as their sole carbon and energy source.