bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis of 1,2‐diacyl‐sn‐glycerophosphadidylserine from egg phosphatidylcholine by phosphoramidite Methodology
Authors: Morillo Margarita , Sagristá M. Luisa , Africa de Madariaga M. , Eritja Ramón
Published: November 2006

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

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

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

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

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

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

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

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

Soy protein isolates were treated with NaCl, Na2SO4, or Na2SO3 (disulfide bond‐cleaving agent) at a pH of 10.0 and 50°C, and the effects of these salts on viscosity, adhesive strength on woods, and water resistance of the treated isolates were investigated. Viscosity and adhesive strength decreased with increasing concentrations of these salts. At a concentration of 0.1 M, these three salts reduced the viscosity of soy proteins with no significant adverse effects on adhesive strength and water resistance. Addition of 0.1 M NaCl, Na2SO4, or Na2SO3 reduced adhesive strength insignificantly from 1230 N to 1120, 1060, or 1013 N, respectively. The viscosity of protein isolate modified at pH 10.0 and 50°C in the absence of salts was >30,000 cP. Treatment with NaCl or Na2SO4 resulted in viscosity reductions to 6000 or 1050 cP, respectively. The Na2SO3 treatment yielded an isolate with the lowest viscosity of 110 cP and which retained adhesive and water‐resistive properties. The water resistance of modified soy proteins with and without 0.1 M Na2SO3 treatment was not significantly different with 3.3 and 6.6% cumulative delaminations occurring after four water soaking cycles. Treatment with 0.1 M Na2SO3 resulted in an isolate with a 28% decrease in disulfide linkages.
Mechanism of physical modification of insoluble soy protein concentrate
Authors: Hua Yu Fei , De Ni Pei , Gu Wen Ying , Shen Bei Ying
Published: November 2006

The mechanism for solubilization of alcohol‐leached soy protein concentrate (ALSPC) by physical modification was studied from the standpoint of molecular interactions, which are related to the differences in protein solubility under different conditions. The low solubility of ALSPC is caused by both noncovalent and covalent forces, but the noncovalent forces do not affect the solubility of modified soy protein concentrate (MSPC). Gel filtration shows that the major constituents of soluble protein from ALSPC and MSPC are protein molecules and protein aggregates, respectively. Physical modification promotes the formation of aggregates that are readily soluble in buffer. Fluorescence spectroscopy further proved that the hydrophobic groups are located in the interior of the aggregates. The reason for the formation of soluble protein aggregates during physical modification of ALSPC is discussed.
Triglyceride composition of ewe, cow, and goat milk fat
Authors: Ruiz‐Sala P. , Hierro M. T. G. , Martínez‐Castro I. , Santa‐María G.
Published: November 2006

The separation and identification of the components in milk fat, which are mainly triglycerides, is a challenge due to its complex composition. A reverse‐phase high‐performance liquid chromatography (HPLC) method with gradient elution and light‐scattering detection is described in this paper for the triglyceride analysis in ewes’ milk fat. Triglyceride identification was carried out by combining HPLC, gas‐liquid chromatography (GLC), and the calculated equivalent carbon numbers of several triglyceride standards. Quantitation of partially resolved peaks in the HPLC chromatogram was accomplished by applying a peak deconvolution program. Forty‐four fatty acids were identified by GLC analysis, but only 19 were used for the following prediction of triglyceride molecular species; 181 triglycerides were identified, some of which were grouped at the same peak and needed application of the deconvolution program. Consequently, coefficients of variation were close to or lower than 5%. Moreover, the triglyceride composition of ewe, cow, and goat milk fat were compared by using these methods. These results show that ewe milk fat is richer in short‐ and medium‐chain triglycerides, and cow milk fat is richer in long‐chain and unsaturated triglycerides.
pH‐metric determination of acid values in vegetable oils without titration
Authors: Tur’yan Ya. I. , Berezin O. Yu. , Kuselman I. , Shenhar A.
Published: November 2006

A new method for determining acid values in vegetable oils has been developed for a nontitration pH‐metric technique with a reagent consisting of 0.20 M triethanolamine in a 1∶1 solution of water and isopropanol. The emulsive properties of this reagent provide rapid (within a minute) and quantitative extraction of free fatty acids from an oil into the solvent phase. Acid values were determined by measuring conditional pH of the emulsified reagent in a pH‐meter with an aqueous reference electrode. Three different applications of this technique are discussed.
Compositional and thermal characterization of genuine and randomized lard: A comparative study
Authors: Al‐Rashood Khalid A. , Abou‐Shaaban Rafiq R. A. , Abdel‐Moety Ezzat M. , Rauf Abdul
Published: November 2006

Composition and thermal characterization of genuine and randomized lard were investigated comparatively in an attempt to find common merits that assess lard detection. The investigation included compositional and positional distribution of fatty acids, triacylglycerol profiling by gas chromatography (GC) and reversed‐phase high‐performance liquid chromatography (RP‐HPLC), as well as thermal behavior by differential scanning calorimetry (DSC) of both samples. Individual and total saturated and unsaturated fatty acid composition in total fats of both genuine and randomized lard were identical. On the other hand, the results of pancreatic lipolysis/GC analysis showed that the average percent palmitic acid [PAEF(%)] and myristic acid [MAEF(%)] enrichment factors of genuine (280 and 270) and randomized lard (110 and 98) were quite different. Thus, application of PAEF to detect randomized lard is of no value. However, normalization of fatty acid distribution by randomization in 2‐monoacylglycerols made the individual and total saturated and unsaturated fatty acids almost identical to that of total fat and neutral triacylglycerols (TG) of lard. TG compositional analysis by GC revealed that both genuine and randomized lard had six dominant TG (C46′C48′C50′C52′C54′ and C56) with quite different concentrations. TG with C52 represent the major constituent of genuine and randomized lard. TG profiling of samples was also carried out by RP‐HPLC with a refractive index detector. The same peaks were eluted in both samples, but the area % of major peaks changed due to randomization. 2‐Palmitooleostearin (SPO) was found in high proportion in lard. However, the ratios of SPO to 2‐palmitooleolinolein of both genuine and randomized lard are close (0.6±0.05) and significantly distinguishable from that of beef (4.24), mutton (6.17), chicken (0.21), and turkey (0.14) fats. The DSC thermogram and thermodynamics of phase transitions of both samples were quite different and do not reveal common characteristic(s) that could be used for immediate detection of lard substances in fat admixtures.
Effect of extraction methods on lipid yield and fatty acid composition of lipid classes containing γ‐linolenic acid extracted from fungi
Authors: Čertík Milan , Andráši Peter , Šajbidor Ján
Published: November 2006

The effect of extraction procedures on the lipid yield and fatty acid composition of total lipid and main lipid structures (phospholipids, diacylglycerols, triacylglycerols, free fatty acids, and sterol esters) of fungal biomass (Mucor mucedo CCF‐1384) containing γ‐linolenic acid (GLA) was investigated. Seventeen extraction methods, divided into three groups, were tested: six with chloroform/methanol, five with hexane/alcohols, and six with common solvents or mixtures. The chloroform/methanol procedure (2∶1) was selected as standard, where lipid yield (TL/DCW, total lipid per dry cell weight) was 17.8%, considered to be 100% of lipids present. All chloroform/methanol extractions yielded more than 83% recorvey of lipids. Use of hexane/isopropanol solvent systems led to a maximum of 75% recovery. The best lipid yield was achieved by a two‐step extraction with ethanol and hexane (120%). Extraction efficiency of the other solvent systems reached a maximum of 73%. Triacylglycerols were the main structures of lipid isolated; only methanol‐extracted lipid contained 58.5% phospholipids. The fatty acid content of total recovered lipid was variable and depended on both the lipid class composition and the solvent system. GLA concentrations in total lipids isolated by hexane/alcohol procedures (7.3–10.7%) are comparable with classical chloroform/methanol systems (6.5–10.0%). The maximal GLA yield was obtained with chloroform/methanol/n‐butanol/water/0.1 M ethylenediaminetetraacetic acid (EDTA) (2∶1∶1∶1∶0.1, by vol) and after two‐step extraction with ethanol and hexane (14.3 and 13.7 g GLA/kg DCW, respectively). The highest GLA content was analyzed in the phospholipid fraction (16.1%) after using chloroform/methanol/n‐butanol/water/0.1 M EDTA (2∶1∶1∶1∶0.1, by vol). Remarkably low concentrations of polyunsaturated fatty acids were determined in the free fatty acid fraction.
The effect ofn‐decanol on solubilization of water‐in‐oil microemulsions and stability of lamellar liquid crystals of alkylphenol ethoxylates
Authors: Guo Rong , Moffett Thomas , Compo Mary E. , Friberg Stig E. , Benton Marcel , Wong Raymond
Published: November 2006

Addition of n‐decanol at appropriate concentrations is beneficial to increasing the solubilization amount of water in a water‐in‐oil microemulsion in the system of nonylphenol ethoxylate/olive oil/water, but it destabilized the lamellar liquid crystal and reduced the solubilization of olive oil in the lamellar liquid crystal.
Carboxymethyl inulin: A new inhibitor for calcium carbonate precipitation
Authors: Verraest Dorine L. , Peters Joop A. , van Bekkum Herman , van Rosmalen Gerda M.
Published: November 2006

A new polysaccharide‐based polycarboxylate, carboxymethyl inulin (CMI), was synthesized recently. The influence of small amounts (0.1–200 ppm) of this material on the crystallization of calcium carbonate, an important scale‐forming salt, is studied. The effects of CMI are compared to those of a commercial inhibitor (a copolymer of acrylate and maleate) and of other carboxymethylated saccharides. It is shown that CMI is a good calcium carbonate precipitation inhibitor. CMI influences the spontaneous precipitation of calcium carbonate, the morphology of the formed crystals (vaterite and calcite), and the growth rate of calcium carbonate seed crystals. The effect is related to the carboxylate content, the chainlength, and the concentration of the additive. For the application of CMI as crystallization inhibitor, products with a high degree of substitution (degree of substitution>1) and a high degree of polymerization (average degree of polymerization = 30) are the most effective. Also, other carboxymethylated polysaccharides (dextrins, cellulose) show good crystallization‐inhibition properties, although the performance of the copolymer of acrylate and maleate is not met. A great advantage of CMI, as compared to carboxymethyl cellulose (CMC), is that aqueous solutions of CMI display, contrary to those of CMC, a very low viscosity. A carboxymethylated disaccharide (carboxymethyl sucrose) has no influence on the calcium carbonate crystallization which shows that the long‐chain character is essential for a polycarboxylate inhibitor.
Preparation ofbis‐quaternary ammonium salts from epichlorohydrin
Authors: Kim Tae‐Seong , Hirao Toshikazu , Ikeda Isao
Published: November 2006

A novelbis‐quaternary ammonium salt was prepared conveniently and almost quantitatively fromN,N‐dimethyldodecylamine, its hydrochloride, and epichlorohydrin. Reaction ofN,N‐dimethyldodecylamine with epichlorohydrin (in the presence of the amine hydrochloride) or various dichloro compounds was investigated by using1H nuclear magnetic resonance. The reaction route was studied by examining the reactivity of reagents with the amine and the effect of reaction temperature. The ease of the reaction with epichlorohydrin was found to be due to the assistance of amine hydrochloride in opening the epoxide ring and to neighboring‐group participation by the hydroxyl group of the intermediatemono‐ammonium salt in the quaternization step. Neighboring‐group participation by the hydroxyl group in these quaternization reactions is also discussed.
Measurement of zeolite, silicate, and phosphate in laundry detergent products by inductively coupled plasma atomic emission spectrometry
Authors: Kawauchi Akihiko , Ishida Masahiro
Published: November 2006

This paper reports the development of a method for simultaneously measuring zeolite, silicate, and phosphate in laundry detergent products by inductively coupled plasma atomic emission spectrometry. A sample is decomposed under alkaline oxidative conditions to decompose zeolite, silicate, phosphate, and organic substances. Then hydrochloric acid is added to the decomposed solution to dissolve aluminum hydroxide precipitate before analysis. This sample preparation procedure was investigated by using a total organic carbon analyzer and was confirmed to be applicable to simultaneous measurements of zeolite, silicate, and phosphate. Relative standard deviation for the analysis is less than 2.1%, recovery is more than 99.0%, and the calibration curve gives a correlation coefficient ofR=1.000. The detection limit of this method for aluminum and silicon is 0.1%, and for phosphorus, 0.2% by weight in the product. This method is applicable to various laundry detergent products that contain zeolite, silicate, or phosphate and is five times faster than the three wet chemical methods.
Turbidimetric analysis of amine oxides and amine oxide‐anionic surfactant mixtures
Authors: Pinazo A. , Domingo X.
Published: November 2006

Automatic turbidimetric analysis has been shown to be a simple and accurate method to determine the actives in anionic surfactants as well as the actives in amine oxides. This technique has been applied to dilute solutions of these surfactants in the μM range. Solutions containing mixtures of anionic surfactants and amine oxides can be positively resolved by turbidimetric titration without interferences. Performing two titrations at different pH values ensures that the amine oxide is completely in its nonionic form or totally protonated and behaving as a cationic surfactant.
Production of triglycerides enriched in long‐chain n‐3 polyunsaturated fatty acids from fish oil
Authors: Moore Stephen R. , McNeill Gerald P.
Published: November 2006

Processes that combine enzymic and physical techniques have been studied for concentrating and separating eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) from fish oil.Candida rugosa lipase was used in hydrolysis reactions to concentrate these acids in the glyceride fraction. By controlling the degree of hydrolysis, two products have been obtained, one enriched in total n‐3(∼50%), the other enriched in DHA and depleted in EPA (DHA∼40%, EPA∼7%). The glyceride fraction from these reactions was recovered by evaporation and converted back to triglycerides by partial enzymic hydrolysis, followed by enzymic esterification. Both reactions were carried out withRhizomucor miehei lipase. DHA‐depleted free fatty acids from aC. rugosa hydrolysis were fractionated to increase the EPA level (∼30%) and re‐esterified to triglycerides by reaction with glycerol andR. miehei.
Production of structured lipids containing essential fatty acids by immobilizedRhizopus delemar lipase
Authors: Shimada Yuji , Sugihara Akio , Nakano Hirofumi , Yokota Tomomi , Nagao Toshihiro , Komemushi Sadao , Tominaga Yoshio
Published: November 2006

An attempt was made to produce structured lipids containing essential fatty acid by acidolysis with 1,3‐positional specificRhizopus delemar lipase. The lipase was immobilized on a ceramic carrier by coprecipitation with acetone and then was activated by shaking for 2 d at 30°C in a mixture of 5 g safflower or linseed oil, 10 g caprylic acid, 0.3 g water and 0.6 g of the immobilized enzyme. The activated enzyme was transferred into the same amount of oil/caprylic acid mixture without water, and the mixture was shaken under the same conditions as for the activation. By this reaction, 45–50 mol% of the fatty acids in oils were exchanged for caprylic acid, and the immobilized enzyme could be reused 45 and 55 times for safflower and linseed oils, respectively, without any significant loss of activity. The triglycerides were extracted withn‐hexane after the acidolysis and then were allowed to react again with caprylic acid under the same conditions as mentioned above. When acidolysis was repeated three times with safflower oil as a starting material, the only products obtained were 1,3‐capryloyl‐2‐linoleoylglycerol and 1,3‐capryloyl‐2‐oleoyl‐glycerol, with a ratio of 86∶14 (w/w). Equally, the products from linseed oil were 1,3‐capryloyl‐2‐α‐linolenoyl‐glycerol, 1,3‐caprylol‐2‐linoleoyl‐glycerol, and 1,3‐capryloyl‐2‐oleoly‐glycerol (60∶22∶18, w/w/w). All fatty acids at the 1,3‐positions in the original oils were exchanged for caprylic acid by the repeated acidolyses, and the positional specificity ofRhizopus lipase was also confirmed to be strict.
Antioxidant activity of tocopherols and phenolic compounds of virgin olive oil
Authors: Baldioli M. , Servili M. , Perretti G. , Montedoro G. F.
Published: November 2006

The antioxidant effects of hydrophilic phenols and tocopherols on the oxidative stability in virgin olive oils and in purified olive oil have been evaluated. Total hydrophilic phenols and the oleosidic forms of 3,4‐dihydroxyphenolethanol (3,4‐DHPEA) were correlated (r=0.97) with the oxidative stability of virgin olive oil. On the contrary, tocopherols showed low correlation (r=0.05). Purified olive oil with the dialdehydic form of elenolic acid linked to 3,4‐DHPEA, an isomer of oleuropeine aglycon, and 3,4‐DHPEA had good oxidative stability. A synergistic effect was observed in the mixture of 3,4‐DHPEA and its oleosidic forms with α‐tocopherol in purified olive oil by the Rancimat method at 120°C.
Fatty acid composition of French infant formulas with emphasis on the content and detailed profile oftrans fatty acids
Authors: Chardigny Jean‐Michel , Wolff Robert L. , Mager Estelle , Bayard Corine C. , Sébédio Jean‐Louis , Martine Lucy , Ratnayake W. M. N.
Published: November 2006

The aim of the present study was to identify and quantitatetrans isomers of C18 fatty acids in some French infant formulas. Twenty powdered infant formulas were purchased in pharmacies and supermarkets in order to assess theirtrans mono‐ and poly‐unsaturated fatty acids content. The fatty acid profiles were examined using methyl and isopropyl ester derivatives. The combination of gas‐liquid chromatography, high‐performance liquid chromatography, and silver nitrate thin‐layer chromatography was needed to describe the detailed fatty acid compositions of the samples, includingtrans isomers of unsaturated C18 fatty acids. All the samples containedtrans isomers of C18∶1 acid (mean level 1.97±0.28% of total fatty acids), with vaccenic acid being generally the major isomer (15 out of 20 samples), thus indicating the origin from bovine milk. All the formulas also contained various isomers of linoleic and α‐linolenic acids, but at lower levels.Trans PUFA isomers are the same as those present in deodorized oils. In conclusion, all the infant formulas analyzed in this study contained sometrans fatty acids, including isomers of essential fatty acids. This should be taken into account in the dietary intake of the newborn.
Gangliosides in membranes fromTorpedo electric organ
Authors: Hann Richard M. , Evans James E. , McCluer Robert H. , Eterovic Vesna A.
Published: November 2006

The electric organ membrane has been the subject of many studies, due principally to its rich content of nicotinic acetylcholine receptor (AChR). Knowing its lipid composition is clearly important. Although its major membrane lipids have been characterized, its ganglioside composition has not been as well‐described. In this study, gangliosides were characterized in membranes prepared from two species of electric organ,Torpedo californica andT. nobiliana. The ganglioside content of total electric organ membranes and AChR‐enriched membranes was similar in both species, accounting for from 0.9 to 1.5% of membrane lipid by weight. However, the AChR‐enriched membranes contained significantly less ganglioside relative to AChR than did the total membrane preparations. Five major gangliosides were purified fromT. californica and identified as II3NeuNAc‐GgOse3 (GM2); II3(NeuNAc)2‐GgOse3 (GD2), IV3NeuNAc, II3NeuNAc‐GgOse4 (GD1a), IV3NeuNAc, II3(NeuNAc)2−GgOse5 (GT1b), and IV3(NeuNAc)2, II3(NeuNAc)2−GgOse4 (GQ1b). Together these five gangliosides accounted for over 90% of the total ganglioside present in the two membrane preparations from both species. The most abundant ganglioside by far was GM2, which accounted for about one‐half of the ganglioside content, followed by GD2. Determination of the N‐fatty acid composition was performed on gangliosides purified fromT. nobiliana. The lower‐order gangliosides, GM2, GD2, and GD1a, contained substantial amounts of very long chain fatty acids (>20 carbons), including α‐hydroxynervonic acid (15–21% of total). In contrast, unsubstituted, 14–18 carbon chains accounted for about 90% of the fatty acids on the two higher‐order gangliosides, GT1b and GQ1b.
Interference of free fatty acids from the hepatopancreas of mussels with the mouse bioassay for shellfish toxins
Authors: Suzuki Toshiyuki , Yoshizawa Roysuke , Kawamura Tomohiko , Yamasaki Makoto
Published: November 2006

Determination of free fatty acids (FFA) in hepatopancreas of mussel,Mytilus coruscus, contaminated by diarrhetic shellfish poisoning (DSP) toxins, was carried out by high‐performance liquid chromatography‐fluorometry as their 9‐anthryldiazomethane derivatives. The FFA in the hepatopancreas of mussels during May 30–June 14 were 443–666 μg/g. A marked increase in FFA content was observed on June 20 (2197 μg/g hepatopancreas) and June 27 (6322 μg/g hepatopancreas). The proportion of polyunsaturated fatty acids (PUFA), including 20∶4n–6, 20∶5n–3, and 22∶6n–3, in mussel FFA increased during the experimental period. Diatoms almost completely dominated the phytoplankton community at the experimental site, suggesting that diatoms were the origin of the PUFA accumulated in mussels. The toxicity of FFA in mussel hepatopancreas on June 27 was sufficiently high as to interfere with the mouse bioassay by injection of an extract of shellfish, the official method for DSP toxin analysis.
Analysis of cereal digalactosyldiacylglycerol molecular species by high‐performance liquid chromatography
Authors: Bergqvist M. H. J. , Kaufmann P.
Published: November 2006

An optimized procedure for the high‐performance liquid chromatographic resolution of molecular species of digalactosyldiacylglycerols from cereals has been developed. The optimal conditions were found by a three‐step optimization strategy by taking eluent composition, eluent profile, system temperature, and flow into consideration. Separation of seven molecular species was achieved for oats and wheat‐kernel digalactosyldiacylglycerols. Molecular species with the same partition number were eluted in the order of increasing unsaturation when utilizing eluent systems based on alcohols and water. This is reversed as compared to what is found when using eluent systems that contain acetonitrile, in which the elution order of the molecular species with the same partition number is according to decreasing unsaturation.
Deacidification of soybean oil by membrane technology
Authors: Raman L. P. , Cheryan M. , Rajagopalan N.
Published: November 2006

After extracting free fatty acids (FFA) from a model crude vegetable oil with methanol, FFA were separated from methanol by nanofiltration. Of the several commercially available membranes that were evaluated, the best resulted in FFA rejection of >90% and flux of >25 Lm−2h−1. A combination of high‐rejection and low‐rejection membranes resulted in a retentate stream of 35% FFA and a permeate stream with less than 0.04% FFA, which can be recycled to the extractor. No alkali is required, no soapstock is formed, and almost all streams within the membrane process are recycled with little discharged as effluent.
In‐situ alcoholysis of soybean oil
Authors: Kildiran Gökhan , Yücel Sevil Özgül , Türkay Selma
Published: November 2006

In‐situ alcoholysis of soybean oil with methanol, ethanol,n‐propanol, andn‐butanol was investigated, as well as the extraction of the oil with these solvents, to explain the progress ofin‐situ alcoholysis and to determine the parameters that affect this reaction. Because methanol is a poor solvent for soybean oil, the amount of oil dissolved in methanol and converted to methyl esters was low afterin‐situ alcoholysis. Ethyl, propyl, and butyl esters of soybean fatty acids could be obtained in high yields fromin‐situ alcoholysis of soybean oil with these alcohols.In‐situ alcoholysis proceeded through dissolution and alcoholysis of triglycerides successively, and the overall reaction rate was determined by the extraction and alcoholysis rates. The parameters, affecting yield and purity of the product esters, were mainly those that favor extraction rate.
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

Impregnation 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

High 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

Kinetics 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

The 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

To 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

The 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

Atlantic 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.