bluuebunny/crossref_metadata_2025 huggingface dataset:
Silver ion high‐performance liquid chromatography of the triacylglycerols ofCrepis alpina seed oil
Authors: Neff W. E. , Adlof R. O. , El‐Agaimy M.
Published: January 2007

The triacylglycerols ofCrepis alpina oil were characterized because this oil has a high concentration of crepenynic (cis‐9‐octadecen‐12‐ynoic) acid, a fatty acid useful in the chemical synthesis of deuterated fats for human metabolism studies. The triacylglycerols were separated from the crude oil by solid‐phase extraction. Resolution, quantitation and isolation of the individual triacylglycerols were performed by silver ion high‐performance liquid chromatography on a commercial column, an acetonitrile in hexane isocratic mobile phase and flame‐ionization detection. Isolated triacylglycerols were identified by capillary gas chromatography of their fatty acid methyl esters. Of the eleven eluted triacylglycerols ofCrepis alpina oil, 85% included 35% tricrepenynoyl, 34% linoleoyldicrepenynoyl and 16% dilinoleoylcrepenynoyl glycerols. Triacylglycerols eluted according to the numbers of alkene and alkyne bonds. Elution times, resolution and quantitation were reproducible over a three‐month period. The flame‐ionization detector response required no response factors for quantitation of the triacylglycerols present inCrepis alpina oil. The silver ion chromatography system permitted the identification of 95% of the triacylglycerols compared to 70% of the triacylglycerols previously identified with reversed‐phase high‐performance liquid chromatography.
Electron impact mass spectra of the oxazoline derivatives of some conjugated diene and triene C18 fatty acids
Authors: Spitzer V. , Marx F. , Pfeilsticker K.
Published: January 2007

The location of the double‐bond systems of some conjugated diene and triene C18 fatty acids (C18∶2[9,11], C18∶2[10,12], C18∶3[9,11,13] and C18∶3[10,12,14]) derived from alkaline isomerization has been determined by gas chromatography/mass spectroscopy analysis of their 4,4‐dimethyloxazoline derivatives. The positions of the double bonds were indicated by a characteristic mass separation of 12 atomic mass units for each olefinic bond. Furthermore, the structure assignments were supported by the presence of prominent formal allylic cleavage peaks.
The effect of polar soil components on the phase inversion temperature and optimum detergency conditions
Authors: Raney Kirk H. , Benson Herbert L
Published: January 2007

Previously reported results have shown that optimum removal of a hydrocarbon soil from polyester/cotton fabric occurs above the cloud point at the phase inversion temperature (PIT) of nonionic surfactant/water/soil systems. Through comparison of phase behavior measurements to radiotracer detergency studies using model sebum soils, i.e., cetane/oleyl alcohol and cetane/oleic acid blends, the relevance of the PIT for removal of nonpolar/polar soil mixtures has also been demonstrated. For these soils, the PIT is typically below the cloud point, and the highest level of soil removal is found between the PIT and cloud point rather than only at the PIT. This relatively temperature‐insensitive soil removal is attributed to the preferential solubilization of polar soil components which continually changes the composition of the residual soil during the washing cycle. These findings explain the long‐observed results that 4‐ to 5‐EO alcohol ethoxylates are preferred for the removal of nonpolar soils while 6‐ to 9‐EO ethoxylates are the more effective surfactants for sebum soils.
Enzymatic synthesis of N‐ε‐acyllysines
Authors: Montet D. , Servat F. , Pina M. , Graille J. , Galzy P. , Arnaud A. , Ledon H. , Marcou L.
Published: January 2007

Chemical synthesis of N‐ε‐acyllysines on an industrial scale corresponds to new requirements in the surfactant field; only one chemical synthesis process is currently known for this type of molecule. A number of organic synthesis conducted in the laboratory so far have not made it possible to consider industrial development. However, biotechnologically, it has been shown that this molecule is easily accessible using a commercially available fixed lipase. Synthesis is carried out by causing a triglyceride to react with the lysine either with or without a solvent. The latter method gives the best results at the current stage of research. Given the availability of at least one fixed lipase on the market today, and the possibility of directly applying the reaction using oils, this reaction could be scaled up rapidly for industrial development.
The influence of water on the synthesis of n‐butyl oleate by immobilizedMucor miehei lipase
Authors: Leitgeb M. , Knez Ž.
Published: January 2007

The influence of initial water concentration on the synthesis of n‐butyl oleate was investigated. The synthesis was done with immobilizedMucor miehei lipase—Lypozyme™—at various reaction conditions. The activity of the enzyme is lower at higher amounts of water. Initial reaction rates, as well as equilibrium conversion, increase at low initial water concentration. Optimal water concentration for the activity of immobilized lipase is temperature dependent at the pressure of 1 bar. Low initial water concentration barely effects equilibrium esterification at 0.032 bar. At high initial water concentrations equilibrium conversion, as well as initial reaction rates, decrease at both pressures.
Vernonia galamensis: A rich source of epoxy acid
Authors: Ayorinde Folahan O. , Butler Boddy D. , Clayton Marcella T.
Published: January 2007

A percolation extraction ofVernonia galamensis seed, affording 38.6% of crude vernonia oil is described. The dark colored crude oil was degummed with water, treated with activated charcoal and bleached with a neutral agent, to give a light colored oil (Lovibond: 0.9 red, 3.5 yellow). Gas chromatographic/mass spectrometric analysis of the refined oil indicates a relative fatty acid composition of 79–81% vernolic (cis‐12,13‐epoxy‐cis‐9‐octadecenoic) acid, 11–12% linoleic acid, 4–6% oleic acid, 2–3% stearic acid, 2–4% palmitic acid, and a trace amount of arachidic acid.
Increase in the γ‐linolenic acid content by solvent winterization of fungal oil extracted fromMortierella genus
Authors: Yokochi T. , Usita M. T. , Kamisaka Y. , Nakahara T. , Suzuki O.
Published: January 2007

The fungal oil extracted fromMortierella ramanniana var.angulispora (IFO 8187) was solvent winterized in order to raise the content of γ‐linolenic acid (GLA). Effects of winterization conditions (solvent, oil concentration in the solvent and temperature) and changes of glyceride compositions were discussed. The fungal oil was separated into four diglycerides and 17 triglycerides (TG) with high performance liquid chromatography. The predominant species were POO, POP and LOP, whose contents were 24.4, 22.9 and 9.4% of the total TG, respectively. Ethanol at 4°C gave the highest GLA content of 10.5% in spite of lower yield than with acetone at −20°C. The highest separation efficiency for GLA (ηGLA) was 0.27 with acetone at −20°C and 10% oil concentration, resulting in 8.3% of GLA from the fungal oil at 5.7% LGA. In case of lower oil concentration at 5–20%, ηGLA showed higher in the following order: acetone (−20°C)>n‐hexane (−20°C)>acetone (4°C)>petroleum ether (−20°C). The winterization process also proved to be effective for the separation of TG type, Sa2U (Sa; saturated fatty acid; U, unsaturated fatty acid) into the crystallized fraction and SaU2 into the liquid fraction. Acetone at −20°C showed higher separation efficiency for triunsaturated TG than the other solvents.
Solvent extraction of fatty acids from natural oils with liquid water at elevated temperatures and pressures
Authors: Briones Jose A. , Mullins Joseph C. , Thies Mark C.
Published: January 2007

The use of liquid water at elevated temperatures and pressures as an extractive solvent for separating mixtures of compounds which occur in natural oils has been studied. A southern pine tall oil and a distillate from the deodorization of soybean oil were extracted with liquid water at temperatures from 298 to 312°C and pressures between 103 and 121 bar. Results indicate that water can be used to extract fatty and resin acids from crude tall oil to obtain a product with a high acid content that produces less pitch during distillation. The process can also be used to extract fatty acids from vegetable oil deodorizer distillate.
Determination of trace elements in edible vegetable oils by atomic absorption spectrophotometry
Authors: Martín‐Polvillo M. , Albi T. , Guinda A.
Published: January 2007

Methods are described for the direct determination of Al, Cr, Cu, Fe, Ni and Pb by atomic absorption spectrophotometry in sunflower oil and olive oils. Metallic contamination after storage under different controlled conditions and in contact with carbon steel, austenitic steel, ferritic steel and aluminum was examined. Additionally, chemical characteristics related to quality (acid value, peroxide value, K270and oxidative stability) and some physical parameters of interest were evaluated after storage. When the samples were atomized directly off the tube wall, matrix interferences were not observed in the determination of Cr, Cu, Ni and Pb, whereas such interferences were noted when Al and Fe were determined. The results indicated that the L'Vov platform for Al and Fe determinations eliminates the matrix effects. Contamination with Fe was only detected in the olive oil that had been in contact with carbon steel, Fe concentration increased from 120±12 to 3,520±157 ppb. The physicochemical characteristics were affected only by the storage conditions, regardless of the metal sheets with which they were in contact. Virgin olive oil showed lowered stability after storage in contact with a carbon‐steel sheet than when stored in absence of metal.
Separation and characterization of pigments from bleached and deodorized canola oil
Authors: Chapman D. M. , Pfannkoch E. A. , Kupper R. J.
Published: January 2007

An analysis of pigments responsible for color formation during bleaching and deodorization of canola oils treated with activated bleaching earth (ABE) or novel mineral‐acid/silica (AS) adsorbents is presented. The chromophores are trace glycerides and were concentrated by silica column chromatography. The concentrated color bodies were hydrolyzed and analyzed as free acids or methyl esters by reversed‐phase high‐performance liquid chromatography with photodiode array and mass spectrometry detection,1H and13C nuclear magnetic resonance and infrared spectroscopies. Absorbance in deodorized oils is mostly from oxygenated C18 and C20 fatty acids with 1 to 4 double bonds. High‐wavelength absorbance in AS‐bleached oils is from conjugated pentane fatty acids that are not observed for ABE‐bleached oils. Thus, both the bleaching agent and the deodorization treatment affect the distribution and concentration of such stable chromophores.
Effects of crystallization conditions on sedimentation in canola oil
Authors: Liu H. , Biliaderis C. G. , Przybylski R. , Eskin N. A. M.
Published: January 2007

The effects of various factors on sediment formation in canola oil were studied. The crystallization temperature of sediment varied with cooling rate, whereas the melting temperature depended on heating rate as well as the cooling rate during sediment formation. The final crystal size depended on cooling rate. The crystal habit of sediment was generally rod‐like but could change to a round and leaf‐like shape at low cooling rates (<0.5°C/min). Crystal nucleation occurred in the initial stage of crystallization, while crystal growth was observed during the whole crystallization process, decreasing as cooling proceeded. Crystal growth rate of the sediment was proportional to the crystal surface area Lecithin did not affect the phase transition temperatures of sediment, but retarded crystal growth.
Sensory stability of canola oil: Present status of shelf life studies
Authors: Malcolmson L. J. , Vaisey‐Genser M. , Przybylski R. , Eskin N. A. M.
Published: January 2007

Sensory studies on autoxidation of canola oil, stored under several variations of Schaal Oven test conditions, suggest an induction period of 2–4 d at 60–65°C. Similar induction periods have been observed between canola and sunflower oils, whereas a longer induction period has been found for soybean oil. Canola oil seems to be more stable to storage in light than cottonseed and soybean oils but is less stable than sunflower oil. Storage stability of products fried in canola oil is similar to products fried in soybean oil. Storage stability of canola and cottonseed oils that had been used in the frying of potato chips showed that canola oil was more prone to autoxidation during storage at 40°C. The presence of light aggravated the oxidative effects and was similar for both oils. Advances in our knowledge about the shelf life of canola oil would be strengthened by standardization of Schaal Oven testing conditions and by specifying the testing protocol for photooxidation studies. Methods for training of panelists and for handling and evaluating oils and fried foods require definition. Rating scales used in the evaluation of oils need to be evaluated to ensure that reliable and valid measurements are achieved. Further progress is needed in the identification of chemical indicators that can be used to predict sensory quality of oils.
Separation of monoacylglycerols by high‐performance liquid chromatography on nitrile‐bonded phase
Authors: Takagi Toru , Ando Yasuhiro
Published: January 2007

Monoacylglycerol molecular species, as their di‐3,5‐dinitrophenylurethane derivatives, were well separated by normalphase high‐performance liquid chromatography on nitrilebonded phase. The peaks emerged in the order 20∶0, 18∶0, 16∶0, 18∶1, 16∶1, 18∶2, and 18∶3. The peaks of 1‐ and 2‐monoacylglycerols with the same acyl group showed complete overlapping. This method could be applied to get acyl compositions in the three positions of triacyl‐sn‐glycerols in their stereospecific analysis.
Microwave heating of cottonseed: A pilot plant study
Authors: Conkerton E. J. , Chapital D. C. , Wan P. J.
Published: January 2007

Two cottonseed samples (50 kg) were exposed to microwaves at 45 KW and 2450 MHz for 4 min in an air temperature of 94°C. The final temperature of the seed was 76°C, and the treatment caused a 20% reduction in seed moisture. Examination of the seed immediately after microwave heating (MWH) indicated no differences in the total or soluble protein content of the meal or the content, quality or color of the oil as compared with unheated seed. There was some reduction in the quality of the oil from unheated seed during storage, but only minimal reduction in the quality of the oil from the MWH samples. Protein quality deteriorated in all samples; however, the deterioration was reduced in the microwave‐heated seed.
Preferential degradation of noncholine phosphatides in soybean lecithin by thermalization
Authors: Weete John D.
Published: January 2007

Purified soybean lecithin and the gum derived from soybean oil processing were heated separately in bulk at 125 to 200°C for 60 min, or at 175°C for 30, 60, 90 and 120 min, and the products were analyzed by thin‐layer chromatography and high‐performance liquid chromatography. It was found that the noncholine phosphatides are preferentially degraded relative to phosphatidylcholine, and that these phosphatides are broken down in the order phosphatidyl‐ethanolamine (PE)>phosphatidylinositol (PI)>phosphatidic acid (PA) with increasing temperature. At 175°C, the heating time required to degrade the noncholine phosphatides was between 30 and 60 min. Diglycerides were the principal products of thermalization at 77% of the total material, indicating that the 3‐phosphoester linkage is the most heat‐labile portion of the noncholine phosphatide molecules. Cleavage of the fatty acids from positions 1 and 2 of the phosphatides was minimal, as indicated by the relatively low amount of free fatty acids (8% of the total) when the lecithin was heated at 180°C for 90 min. The appearance of brown discoloration, characteristic of heated lecithin, coincided mainly with the decomposition of PE.
Antioxidant constituents of peanut oil
Authors: Gopala Krishna A. G. , Prabhakar J. V.
Published: January 2007

The components responsible for increased stability of raw peanut oil at a high relative humidity (RH) of 91% were examined in peanut oil and methyl linoleate systems. Of the constituents, the native gums, which were mostly phospholipids and glycolipids, showed increased antioxidant activity at 91% RH. The isolated components of the gums, namely phospholipids and glycolipids, were prooxidant individually or in combination. Tocopherols did not show increased antioxidant activity at 91% RH.
Effect of saline irrigation water on olive oil composition
Authors: El‐Agaimy M. A. , Neff W. E. , El‐Sayed M. , Awatif I. I.
Published: January 2007

Virgin olive oils were obtained in Egypt from fruits of olive trees irrigated with waters of different salinity concentration (control, 1800, 3600 and 6000 ppm) during the 1992 season. The effect of water salinity on olive oil fatty acid, fatty acid location in triacylglycerol moiety, triacylglycerol, sterol and tocopherol composition was determined. Oleic acid slightly increased and linoleic decreased in the total fatty acid composition, as well as on glycerol carbon‐2 and‐1(3), with increased water salinity. Trioleoyl, stearoyldioleoyl and palmitoyldioleoyl glycerols are slightly increased with increased water salinity. Total tocopherol was 87.7 mg/kg in the control and increased to 147.0 mg/kg for water with 1800 ppm salinity. At higher salinity concentration, total tocopherol decreased to 107.2 and to 89.1 mg/kg for water salinities of 3600 and 6000 ppm, respectively. The same trend was observed for α, β and γ‐tocopherols. Campesterol and β‐sitosterol were increased with water salinity of 1800 ppm and decreased when water salinity increased further. Stigmasterol increased at water salinity of 3600 ppm and decreased sharply when the salinity was increased to 6000 ppm. These olive oil composition studies showed that although water salinity may have some compositional effects, there was no major adverse effect on fatty acid, triacylglycerol, triacylglycerol fatty acid location, sterol and tocopherol composition for oil from olives of trees grown with water with a salt composition of up to 6000 ppm.
Protein nitrogen combustion method collaborative study I. Comparison with smalley total Kjeldahl nitrogen and combustion results
Authors: Berner David L. , Brown Janet
Published: January 2007

During 1993–1994, a collaborative study of the determination of the nitrogen content of oilseed meals by the nitrogen combustion method was conducted among 24 laboratories in seven countries for the analysis of cottonseed, soybean (two samples), peanut, canola and safflower (two samples). These meals were also analyzed by the CuSO4/TiO2 Kjeldahl method (Official Methods and Recommended Practices of the American Oil Chemists' Society, 4th edn., 1989, Method Ba 4d‐90) in the 1993–1994 Smalley Check Sample Program Oilseed Meal Series [Brown, J.,INFORM 5:640 (1994)]. Some participants used commercial nitrogen combustion instruments. In the Smalley Program, CuSO4/TiO2 Kjeldahl analysis gave nitrogen values that ranged from 0.05 to 0.13% lower than values obtained by the combustion method in the collaborative study. Nitrogen values obtained by the combustion method on an optional basis in the Smalley Program were generally lower by 0.01 to 0.03% than nitrogen values obtained by the combustion method in the collaborative study reported here.
trans‐Polyunsaturated fatty acids in French edible rapeseed and soybean oils
Authors: Wolff Robert L.
Published: January 2007

The fatty acid compositions of rapeseed and soybean oils marketed in France have been determined by gas liquid chromatography on a fused‐silica capillary column coated with a 100% cyanopropyl polysiloxane stationary phase. Under the operating conditions employed, methyl esters of linolenic acid geometrical isomers could be separated and quantitated easily without any other complementary technique. With only one exception, all samples under study (eight salad oils and five food samples) contain geometrical isomers of linolenic acid in measurable, although variable, amounts. Totaltrans‐18:3 acids may account for up to 3% of total fatty acids. This value corresponds to a degree of isomerization (percentage oftrans isomers relative to total octadecatrienoic acids) of 30%. Examination of our data indicates that the distribution pattern of linolenic acid geometrical isomers does not depend on the degree of isomerization. The two main isomers always have thec,c,t and thet,c,c configurations. These isomers occur in the almost invariable relative proportions of 47.8±1.7% and 41.1±1.0%, respectively. The third mono‐trans isomer is present in lower amounts−6.5±0.7%. The only di‐trans isomer that can be quantitated with sufficient accuracy is thet,c,t isomer (4.9±1.5%). Mono‐trans isomers of linoleic acid are also present in these oils. However, their maximum percentages are lower than those determined for linolenic acid geometrical isomers. In the oils showing the highest degrees of isomerization,trans isomers of linoleic acid account for 0.5% (rapeseed oils) and 1% (soybean oils) of total fatty acids. Taking into account all data, it would appear that the probability of isomerization of linolenic acid is about 13–14 times that of linoleic acid.
Lipase‐catalyzed enantioselective acidolysis of chiral 2‐methylalkanoates
Authors: Engel Karl‐Heinz
Published: January 2007

Lipase fromCandida cylindracea catalyzes the acidolysis between racemic 2‐methylalkanoates and fatty acids in heptane with a preference for the (S)‐configurated esters. Velocity and enantioselectivity of the acyl transfer are strongly influenced by the structures of the initial substrates. The potential of this strategy for kinetic resolution of the enantiomers of chiral 2‐methylalkanoates is demonstrated. Limitations of the procedure due to the reversible character of the reaction are discussed.
Peroxide synthesis from alkyl halides, alcohols and alkenes
Authors: Foglia Thomas A. , Silbert Leonard S.
Published: January 2007

New and improved methods of peroxide synthesis have been developed along with advances in peroxide analyses. Hydroperoxides were obtained by one of three methods: i) perhydrolysis of alkyl mercury tetrafluoroborates (RHgBF4); ii) perhydrolysis of alkyl trifluoromethanesulfonates (triflates, ROSO2CF3); and iii) photooxygenation of unsaturated fatty esters (methyl oleate) with sensitizer in a phase transfer catalysis (PTC) system. Dialkyl peroxides also were prepared by three methods: hydroperoxidation of the mercury and triflate intermediates and an innovation of the reaction of superoxide anion with alkyl halides in a PTC system. Chromatographic—gas‐liquid chromatography (GLC) and high‐performance liquid chromatography (HPLC)—methods were examined in detail for compositional analysis of hydroperoxides and dialkyl peroxides in reaction mixtures and for purity determinations. Dialkyl peroxides were further analyzed by an improved rapid iodometric method by using strong non‐oxidizing acid (HCLO4) and iron catalysis.
Effect of water activity on secondary products formation in autoxidizing methyl linoleate
Authors: Gopala Krishna A. G. , Prabhakar J. V.
Published: January 2007

The role of water activity on the formation of peroxides and carbonyl compounds during lipid oxidation is important to know because there could be either beneficial or detrimental effects of water activity on lipid oxidation in stored foods. Therefore, methyl linoleate was chosen as a model lipid and was autoxidized to 1% at water activity ranging from 0.02 to 0.79 at 37°C. Oxygen uptake was monitored manometrically. The peroxide and carbonyl contents were determined upon termination of the autoxidation studies. Methyl linoleate autoxidation was characterized by three phases: i) an initial induction period of no oxygen absorption; ii) a slow rate of oxygen absorption, up to 0.15% oxidation; and iii) a relatively faster rate of oxygen absorption beyond 0.15% up to 1% oxidation. Water activity had considerable influence during the first phase. There was no induction period at or below water activity 0.22. The induction period begins at water activity 0.32 and could be extended to a limit with increase in water activity. Once the induction period was passed water activity had no influence on the rate of oxidation. However, during the second and third phases water activity becomes important in the stabilization of peroxides/hydroperoxides and decides the course of secondary reactions that follow peroxide decomposition. Higher water activity values, particularly water activity 0.67, tended to stabilize peroxides. Water activity had considerable influence on the formation of secondary products of autoxidation as evidenced by the variation in the type and quantity of carbonyl compounds at different water activity values.
γ‐Linolenic acid concentrates from borage and evening primrose oil fatty acidsvia lipase‐catalyzed esterification
Authors: Syed Rahmatullah M. S. K. , Shukla V. K. S. , Mukherjee K. D.
Published: January 2007

γ‐Linolenic acid (GLA, all‐cis 6,9,12‐octadecatrienoic acid) has been enriched from fatty acids of borage (Borago officinalis L.) seed oil to 93% from the initial concentration of 20% by lipase‐catalyzed selective esterification of the fatty acids withn‐butanol in the presence ofn‐hexane as solvent. The immobilized fungal lipase preparation, Lipozyme, used as biocatalyst, preferentially esterified palmitic, stearic, oleic and linoleic acids and discriminated against GLA, which was thus concentrated in the unesterified fatty acids fraction. In the absence of hexane, concentrate containing about 70% GLA was obtained. When the reaction conditions, optimized for borage oil fatty acids, were applied to fatty acids of evening primrose (Oenothera biennis L.) oil, concentrates containing 75% GLA were obtained. From both oils, GLA concentrates were prepared efficiently in short reaction times (1–3 h) at 30–60°C. The process can be applied for the production of GLA concentrates for dietetic purposes.
Acidolysis of babassu fat catalyzed by immobilized lipase
Authors: Gioielli L. A. , Pitombo R. N. M. , Vitolo M. , Baruffaldi R. , Oliveira M. N. , Augusto M. S.
Published: January 2007

The lipase‐catalyzed interesterification of oils and fats gives products that are unobtainable by chemical interesterification methods. Acidolysis of babassu fat and palmitic acid, catalyzed by immobilized lipase (Lipozyme; Novo Industri, Bagsveard, Denmark), was studied. The reactions were performed at 65°C with 5% w/w enzyme for 4 h. The molar proportions of babassu fat/palmitic acid were 1∶0.1, 1∶0.3 and 1∶0.5. At the end of the reaction period, the catalyst particles were removed by filtration, and the residual oil was extracted with organic solvent (diethyl ether). The recovered particles were then reused. The palmitic acid content of babassu fat before and after acidolysis changed from 10 to 22% at a molar proportion of 1∶0.5. The equilibrium was attained in about 4 h. The original water and enzymatic activities of Lipozyme were maintained after acidolysis. Water sorption isotherms of the immobilized enzyme were determined at 25, 35 and 45°C. From the temperature dependence of the isotherms, isosteric heats of sorption were evaluated by means of the Clausius Clapeyron equation. Monolayer moisture content was calculated by means of the B.E.T. and Guggenhein‐Anderson‐De Boer analyses.
Synthesis of mono‐ and diglycerides in water‐in‐oil microemulsions
Authors: Singh C. P. , Shah D. O. , Holmberg Krister
Published: January 2007

Enzyme‐catalyzed esterification was carried out in single‐phase, oil‐continuous microemulsions. The lipozyme was solubilized, along with glycerol and water, in the aqueous core of water/diethylhexyl sodium sulfosuccinate/hydrocarbon microemulsion system. Upon addition of fatty acid, mono‐ and diglycerides were formed, due to the esterification reaction taking place at the interface of the droplets in the microemulsion. The initial rate of conversion of oleic acid increases with oil chainlength of the continuous phase whereas final conversion is maximum for hexane. The conversion of stearic acid is 30% whereas conversion of oleic acid is 70%. The percent conversion of various fatty acids in the same continuous medium increases with fatty acid chainlength. The oleic acid/glycerol ratio is an important parameter for optimum conversion of oleic acid into glycerides. The yield can be increased by subsequent addition of glycerol after equilibrium is reached. High‐performance liquid chromatography analysis of samples from microemulsions shows the presence of mono‐ and diglycerides. Possible mechanisms for the abovementioned effects are discussed.
Bleaching rapeseed and soybean oils with synthetic adsorbents and attapulgites
Authors: Boki Keito , Mori Hidehito , Kawasaki Naohito
Published: January 2007

Efficiencies of synthetic adsorbents and attapulgites in bleaching alkali‐refined rapeseed and soybean oils ranged from 13–53% and 93–97%, respectively. The Freundlich equation was more applicable than the Langmuir equation to the experimental adsorption isotherms of β‐carotene on attapulgites. Bleaching with attapulgites reduced tocopherols by 12.5–29.5% in rapeseed oil and by 18.9–44.8% in soybean oil. Cosmetic‐grade attapulgite was superior to the others in bleaching efficiency, equilibrium amount adsorbed and removal of free fatty acids.
Antioxidant efficacy of amino acids in methyl linoleate at different relative humidities
Authors: Gopala Krishna A. G. , Prabhakar J. V.
Published: January 2007

Antioxidant efficacy of the amino acids methionine, tryptophan, aspartic acid, serine, alanine and arginine in methyl linoleate were compared to a methyl linoleate control at 2,50 or 79% relative humidity (RH) at 37°C. Antioxidant efficacy varied with RH and the individual amino acids. Arginine had the highest antioxidant efficacy at all RH values compared to the control. The efficacy of alanine was equal to that of arginine at RHs of 50 and 79% but was lower at 2% RH. The presence of aliphatic, alkaline amino, hydroxyl or thiol groups in the side chain of the amino acids increased the antioxidant efficacy at high RHs.
Molecular interactions in monolayers: Molecular association and foam stability of fatty acids and alcohols
Authors: Shah Dinesh O. , Dysleski Cynthia A.
Published: January 2007

Surface pressures and potentials of monolayers of stearic acid and of mixed monolayers of stearic acid‐stearyl alcohol (1:1 and 1:3 molar ratios) were measured on buffered subsolutions at various pH values. The molecular area‐pH plot for these monolayers at a surface pressure of 10 dynes/cm showed a maximum at pH 9.0. The average area per molecule in the mixed monolayers decreased at pH 9, as the per cent of stearyl alcohol was increased. The foam characteristics of decanoic acid, and 1:1 and 1:3 mixtures of decanoic acid‐decanol solutions were studied at various pH values. At pH 9.0, foams of decanoic acid and of 1:1 mixture of decanoic acid‐decanol had least stability. In contrast, the foam of the 1:3 mixture had maximum stability at pH 9.0. The results suggest that a stoichiometric association between a fatty acid and an alcohol strikingly influences the foam stability.
Dietary fat composition and tocopherol requirement: II. Nutritional status of heated and unheated vegetable oils of different ratios of unsaturated fatty acids and vitamin E
Authors: Alfin‐Slater R. B. , Morris R. B. , Aftergood L. , Melnick D.
Published: January 2007

In studies conducted on male and female rats and involving evaluation of growth, reproductive and lactation performances and of lipid peroxidation, no evidence could be found for the need for added vitamin E (a‐tocopherol) over and above that naturally present as tocopherols in the vegetable oils investigated. These oils are in common usage in industry, i.e., liquid nonhydrogenated cottonseed oil, a lightly hydrogenated cottonseed oil and a hydrogenated soybean oil shortening. The ratio of polyunsaturates to total tocopherol in the test oils varied from 640:1 to 9:1. Even those oils obtained from a commercial frying operation after a steady state had been attained contained sufficient vitamin E to meet dietary requirements. Results of in vitro peroxide hemolysis tests conducted on the red blood cells of the test animals did not correlate well with biological performance.
Surface active properties of sulfonated isoricinoleic acid
Authors: Ahmad Ishtiaque , Singh Jasbhinder
Published: January 2007

A new anionic surfactant, sulfonated isoricinoleic acid, was prepared by sulfonation of isoricinoleic acid. Surface active properties, such as surface tension, interfacial tension, emulsifiability, dispersibility and foaming power of sulfonated isoricinoleic acid (SIRA), and sulfonated castor oil or turkey red oil (TRO) were studied and compared. The comparative studies showed that SIRA is a better surface active agent than TRO.
Kinetics of liquid phase hydrogenation of cottonseed oil with nickel catalysts
Authors: Krisnaiah D. , Sarkar S.
Published: January 2007

The hydrogenation of cottonseed oil has been carried out in a batch reactor using both unmodified and chromia modified nickel catalysts. The process variables include chromium to nickel atomic ratio (0.00–0.35), catalyst particle size (200–400 micron), temperature (120–140°C) and pressure (5–10 bar). Chromia was found to suppress the stearate formation completely, although it retarded the overall hydrogenation activity of nickel. Its optimum content in the catalyst was found to be 0.17 Cr/Ni atomic ratio; the data corresponded to 5 hr reaction time. The kinetics of the process was tested and found to follow a first order reaction with respect to linoleate and half order with respect to hydrogen. The activation energy was found to be 11.8 kcal/mole.
Effect of packaging materials on storage stability of crude palm oil
Authors: Nkpa Nnadozie N. , Osanu F. C. , Arowolo T. A.
Published: January 2007

Lacquered metal cans, green glass bottles, amber glass bottles, clear glass bottles and clear plastic bottles filled with freshly produced Nigerian crude palm oil were stored in direct sunlight (40±1°C) and in the dark (27±1°C). Assessment of the stability of the oils towards hydrolytic and oxidative deterioration was made periodically by measuring the free fatty acid, peroxide and anisidine values over a period of 98 days. The study showed that crude palm oil packaged in plastic bottles and clear glass bottles recorded higher total oxidation values than oils packaged in either lacquered metal cans or amber and green glass bottles. Lacquered metal cans gave the greatest protection against oxidation. Oxidation proceeded faster in cases where the packaging materials were stored in direct sunlight.
Hydrogenation of 9‐octadecenoic acid by Ru−Sn−Al2O3catalysts: Effects of catalyst preparation method
Authors: Tang Thin‐Sue , Cheah Kien‐Yoo , Mizukami Fujio , Niwa Shu‐ichi , Toba Makoto
Published: January 2007

Evaluation of the method of preparation and the sequence of metal incorporation onto the catalyst showed that they had profound effects on the catalytic behavior of Ru−Sn−Al2O3catalysts used in the selective hydrogenation of oleic acid to 9‐octadecen‐1‐ol. When Ru was loaded first onto the support and then followed by Sn, the catalyst had lower activity but greater ability to preserve the unsaturated bond. On the other hand, when the sequence of loading was reversed, the behavior of the catalyst changed correspondingly, i.e., the catalyst showed higher activity but poorer ability to protect the unsaturated bond. The metal particles incorporatedviathe sol‐gel method were finely and evenly distributed on the support. As such, they were more readily shielded by the second metal particles that were subsequently incorporatedviathe impregnation process. When both metals were loadedviathe sol‐gel process, the best result was obtained with superior performance in activity, as well as selectivity in the preservation of double bond.
Autoxidative dimerization of methyl linolenate and its monohydroperoxides, hydroperoxy epidioxides and dihydroperoxides
Authors: Neff W. E. , Frankel E. N. , Fujimoto K.
Published: January 2007

The structures of dimers and oligomers produced by autoxidation of methyl linolenate and its purified oxidation products were investigated to obtain a better understanding of the mechanism of oxidative deterioration of unsaturated lipids. The dimers were separated by gel permeation chromatography, characterized by molecular weight determinations before and after sodium borohydride reduction, and analyzed by ultraviolet, infrared,1H NMR and fast atom bombardment mass spectrometry. Autoxidation of methyl linolenate at 40 C to peroxide value of 1062 produced 6.8% dimers mainly derived from hydroperoxides, hydroperoxy epidioxides and dihydroperoxides. These dimers were 88% peroxide‐linked (C‐O‐O‐C) and 12% ether‐ (C‐O‐C) and/or carbon‐linked (C‐C). Autoxidation of methyl linolenate monohydroperoxides at 40 C produced dimers that were 72% peroxide‐ and 28% ether/carbon‐linked. Thermal decomposition of linolenate hydroperoxides at 150 C gave dimers that were 100% ether/carbon‐linked, and catalytic decomposition with ferric chloride‐ascorbic acid at room temperature gave dimers with 43% peroxide and 57% ether/carbon linkages. Autoxidation of linolenate hydroperoxy epidioxides at 40 C produced dimers containing hydroperoxy epidioxides, dihydroperoxides and monohydroperoxides joined with peroxide and ether/carbon linkages. Under the same conditions, autoxidation of linolenate dihydroperoxides produced dimers containing dihydroperoxides and hydroperoxy epidioxides joined with peroxide and ether/carbon linkages. These dimers contribute to oxidative and flavor deterioration of polyunsaturated fats in the same way as the hydroperoxide precursors by further decomposition to produce volatile compounds.
Effects of chain length, conformation and α‐form packing arrangement on theoretical monoacid triglyceride β′‐forms
Authors: Hagemann J. W. , Rothfus J. A.
Published: January 2007

Theoretical β′‐form monoacid triglycerides of odd and even chain length having a bend in the glycerol region were prepared by bond rotations from selected α‐form conformers. The shapes of such β′‐forms depend on the bonds rotated and the direction of rotation. Intermolecular minimization procedures determined best‐fit positions around a centralized molecule, which revealed unsymmetrical packing among five of nine different energetically‐favored orthorhombic subcell arrangements. Methyl gap energy is influenced more by overall triglyceride conformation than by whether the fatty acid chains have an odd or even number of carbon atoms. Total lattice‐packing energies varied little between odd and even chain lengths; thus, many combinations of conformation and subcell arrangement are consistent with known X‐ray long spacings and polymorphic behavior of β′‐forms.
Competitive adsorption of lutein from soy oil onto rice hull ash
Authors: Palaniappan Sevugan , Proctor Andrew
Published: January 2007

Adsorption of lutein from crude soybean oil onto acid ash prepared from rice hulls displayed Freundlich‐type isotherms. Different isotherms were obtained depending on the amount of adsorbent used. Addition of isopropanol to the miscella and water deactivation of the adsorbents decreased lutein adsorption. These observations suggested competitive adsorption based on polarity. Triglycerides were adsorbed to a greater extent than lutein, probably due to their larger concentrations. These findings parallel the adsorption behavior of silicic acid.
Characterization and processing of cottonseed oil obtained by extraction with supercritical carbon dioxide
Authors: List G. R. , Friedrich J. P. , Pominski J.
Published: January 2007

Extraction of flaked cottonseed with supercritical carbon dioxide at temperatures of 50–80 C and pressures of 8,000–15,000 psi yields an improved crude cottonseed oil compared to those obtained by conventional solvent or expeller processes. Improvements include lighter initial color, less refining loss and lighter refined bleached colors. Crude cottonseed oils obtained by supercritical fluid extraction require less refining lye and show less tendency to undergo color fixation while in storage.
Properties and processing of corn oils obtained by extraction with supercritical carbon dioxide
Authors: List G. R. , Friedrich J. P. , Christianson D. D.
Published: January 2007

Crude oils were extracted from wet‐ and dry‐milled corn germs with supercritical carbon dioxide (SC‐CO2) at 50–90 C and 8,000–12,000 psi and were characterized for color, free fatty acids, phosphorus, refining loss, unsaponifiable matter, tocopherol and iron content. They were compared with commercial products. Extraction of wetmilled germ with SC‐CO2 has some advantages over the conventional prepress solvent method commonly used in the industry. For example, SC‐CO2 extraction of wet‐milled germ at 50 C and 8,000 psi yields crude oil with a lower refining loss and a lighter color. After laboratory processing, a light‐colored, bland salad oil is obtained. Crude, refined, bleached and deodorized oils from SC‐CO2‐extracted dry‐milled germ appear equivalent to those obtained by expeller pressing.
Characteristics and composition of newer varieties of indian castor seed and oil
Authors: Lakshminarayana G. , Paulose M. M. , Kumari B. Neeta
Published: January 2007

Seventeen newer varieties of castor seed grown in different parts of India and the oils extracted therefrom were analyzed. The seed characteristics varied as follows: 100‐seed weight, 15.2–30.2 g; 100‐seed volume, 15.0–32.5 ml; kernel, 64–75%; oil, 46.0–51.8%; protein, 17.1–24.4%; crude fiber, 18.2–26.5%, and ash, 2.1–3.4%. Oil characteristics were: acid value, 1.0–2.9; saponification value, 176.2–183.7; iodine value, 81.4–88.1, and hydroxyl value, 159.2–167.1. Ricinoleic acid content varied from 87.4% to 90.4%.
Anticarcinogenic effect of selenium in the dimethylbenz(a)anthracene‐induced mammary tumor model in rats
Authors: Ip Clement
Published: January 2007

Using the dimethylbenz(a)anthracene‐induced mammary tumor model in rats, our studies indicated that there was a dose‐response relationship between dietary selenium supplementation and the inhibition of mammary carcinogenesis. The degree of inhibition was proportional to the level of dietary selenium up to 5 ppm, at which point toxicity in the form of a reduction in weight gain was evident. Moreover, it was observed that the chemopreventive efficacy of selenium was influenced by the dose of carcinogen as well as the fat intake of the animals. By supplementing selenium for defined periods of time, we concluded that selenium inhibited both the initiation and the promotion phases of chemical carcinogenesis, and that a continuous intake of selenium was necessary to achieve maximal suppression of tumor growth. In an attempt to improve the efficacy of lower levels of selenium, we conducted another series of experiments in which selenium and vitamin E were tested in combination. Results showed that although vitamin E alone had no prophylactic effect against tumorigenesis, it potentiated the ability of selenium to inhibit the development of mammary tumors. Further investigation suggested that the anticarcinogenic action of selenium could not be explained by its antioxidant function in lipid peroxidation. On the other hand, vitamin E might be able to provide a more favorable environment against oxidant stress to assist selenium in exerting its inhibitory effect through some other mechanisms.
Role of lipids in tumorigenesis
Authors: Carroll K. K.
Published: January 2007

High fat diets are associated with increased mortality from cancer at various sites, including breast, colon, rectum, prostate, ovary and pancreas. Additional evidence for this association has been obtained for some sites (e.g. mammary gland and colon) by studies on experimental animals. Dietary polyunsaturated fats increase the yield of mammary tumors in rats more effectively than saturated fats, apparently because of their higher content of essential fatty acids. Saturated and polyunsaturated fats are about equally effective in enhancing the yields of colon tumors in rats. Dietary fat appears to act as a promoter rather than an initiator of tumorigenesis, although the exact mechanisms of action are not known. Mammary tumorigenesis in rats can be inhibited by reducing the level of dietary fat after a period of promoting with a high fat diet. Decreasing the present high levels of fat in American diets might help to reduce cancer incidence and mortality.
Effects of selected chemical treatments on quality of fats used for deep frying
Authors: Mancini‐Filho J. , Smith L. M. , Creveling R. K. , Al‐Shaikh H. F.
Published: January 2007

Maintaining quality of fats and oils used for deep frying is important in food preparation. In this study, commercially used shortenings were treated with various adsorbents and/or additives with a view to extending their useful life. Quality parameters monitored were increases in dielectric constant, free fatty acids, color (absorbance at 420 nm) and total polar materials. Bleaching clay, charcoal, magnesium oxide and Celite, and their mixtures, effectively reduced one or more of these parameters in used vegetable and animal‐vegetable shortenings. However, when the treated fats were used to fry more french fried potatoes in the laboratory, they often deteriorated more rapidly than the untreated control fats. The daily addition of 200 ppm ascorbyl palmitate to fresh, partially hydrogenated soybean oil shortening used to fry french fries retarded free fatty acid development but increased color development and dielectric constant. Treatments employed to extend the useful life of frying fats improved quality parameters, but continued frying after treatment led to greater deterioration than occurred in the untreated control samples.
Effect of browning reaction products of phospholipids on autoxidation of methyl linoleate
Authors: Husain S. Rafat , Terao J. , Matsushita S.
Published: January 2007

Methyl linoleate was allowed to autoxidize in bulk phase at 50 C in the presence of either synthetic phospholipids consisting of saturated fatty acids or egg yolk phospholipids to estimate the effect of base group and fatty acid moiety of phospholipids on oil autoxidation. Dipalmitoyl phosphatidylcholine (DPPC) and dipalmitoyl phosphatidylethanolamine (DPPE) exhibited poor antioxidant activity at 50 C and showed no synergistic effect with α‐tocopherol. The addition of phosphatidylcholine (PC) and phosphatidylethanolamine (PE) of egg yolk accelerated the oxidation of methyl linoleate. However, egg yolk PC and PE collected at various stages of heating at 180 C inhibited hydroperoxide formation at the initial stage of oxidation. This effect could be attributed to the browning products formed during heating reaction. Thus, browning color products formed from unsaturated phospholipids at high temperatures may influence oil stability, although the base group of phospholipids did not exert any significant effect.
Some synthetic detergents from petroleum products
Authors: Fam S. A. , El‐Sukkary M. M. A. , El‐Dib F.
Published: January 2007

Deodorized and dewaxed Egyptian petroleum fraction, boiling range 200–270 C, was subjected to liquid phase oxidation at various temperatures in the presence of Co acetate as catalyst. The synthesized naphthenic acids were then converted to naphthenic acid amides and naphthenic alcohols. These products were ethoxylated to different mole ratios of ethylene oxide. The ethoxylates with an average 5 mol ethylene oxide/mol prepared hydrophobes were sulphated and phosphated to anionics.

The surface active properties of all the nonionic and anionic surfactants were evaluated.