bluuebunny/crossref_metadata_2025_split huggingface dataset:
Isothermal crystallization kinetics of refined palm oil
Authors: Chen C. W. , Lai O. M. , Ghazali H. M. , Chong C. L. 
Published: November 2006

AbstractThe induction times for the crystallization, under isothermal conditions, of refined, bleached, and deodorized palm oil from the melt were studied by viscometry. At temperatures below 295 K, the crystallization of palm oil was observed to occur in a two‐stage process. This two‐stage process was caused by the fractionation of palm oil, most probably into the stearin and olein fractions. At temperatures higher than 295 K, only a single‐stage crystallization process was observed. As seen under polarized light microscopy, spherical crystals were initially formed from the first fraction at temperatures from 287 to 293 K. The diameters of these spherical crystals decreased as the temperature increased. After that, needle‐shaped crystals were formed from the second fraction and continued to grow from the surface of these spherical crystals until the spherical crystals were fully enclosed, i.e., the cocrystallization of two polymorphs was observed. At temperatures higher than 293 K, the needle‐shaped crystals formed from a mixture of the two fractions were found to be the only polymorphs developed with the onset of crystallization. X‐ray diffraction results showed that for temperatures below 295 K, the spherical crystals formed from the first fraction were in α form, whereas the needle‐like crystals that nucleated later from the second fraction were in β′ form. β′ crystals were the only polymorphs formed for temperatures above 295 K. The results obtained were in good agreement with the discontinuity observed in the induction time vs. temperature curve. Activation free energies for nucleation were calculated according to the Fisher‐Turnbull equation for the various polymorphic forms. Viscometry was observed to be a sensitive method for characterizing the overall crystallization process. This technique is suitable for induction time studies of palm oil crystallization, especially at lower temperatures and with viscous oil.
Trans FA and solid fat contents of margarines marketed in Turkey
Authors: Tekin Aziz , Cizmeci Melih , Karabacak Hulya , Kayahan Muammer 
Published: November 2006

AbstractTrans FA (TFA), solid fat contents (SFC), and slip melting points of 12 different tub and stick margarines marketed in Turkey were examined in this study. No trans isomers were found in four margarines, which suggests they were formulated from interesterified or blended fats and oils. The products with no TFA generally had more short‐chain saturated FA, which suggests coconut oil‐based oil components. TFA content of the other 10 products varied from 7.7 to 37.8%. Compared to the products formulated in North America, Turkish margarines contain more TFA and have higher SFC.
Kinetics of geometrical isomerization of unsaturated FA in soybean oil
Authors: Gerčar Nadja , Šmidovnik Andrej 
Published: November 2006

AbstractLaboratory treatment of soybean oil were carried out at the following conditions: atmospheric pressure in the presence of air or nitrogen at different temperatures ranging from 160 to 250°C for 12 to 72 h. These conditions were used to study geometric isomerization of cis,cis‐linoleic and cis,cis,cis‐linolenic acid in the presence or in the absence of oxidative degradation reactions. Based on these experiments, a model of consecutive, parallel reactions was developed to describe the reaction steps occurring in the soybean oil during heating at constant temperature. For both cis,cis‐linoleic and cis,cis,cis‐linolenic acid, the reaction of formation isomers followed a first‐order reaction, and the rate constant of isomerization varied according to the Arrhenius law. The isomerization rate constant for linoleic acid was 9.57×10−3±0.50 h−1 in the presence of oxygen and 7.39×10−3±0.39 h−1 in its absence, and the isomerization rate constant for linolenic acid was 1.18×10−1±0.10 h−1 in the presence of oxygen and 0.87×10−1±0.07 h−1 in its absence (all obtained at 250°C).
The role of water in the oxidation process of extra virgin olive oils
Authors: Ambrosone L. , Angelico R. , Cinelli G. , Di Lorenzo V. , Ceglie A. 
Published: November 2006

AbstractDifferent emulsifying techniques were used to study the influence of water on the oxidative degradation of extra virgin olive oil. The emulsions of water/extra virgin olive oil, oxidized with O2, UV radiation, and Air, were prepared by dispersing water under different conditions. Oil oxidation, monitored by measuring the PV and polyphenolic content, was greater for emulsions obtained with low dispersing power. A linear model was used to correlate the PV and the polyphenolic content with dispersing energy. An important result was that the dispersed water exerted a positive antioxidant effect on the oil.
Rapid MS method for analysis of cocoa butter TAG
Authors: Kurvinen J. ‐P. , Sjövall O. , Tahvonen R. , Anklam E. , Kallio H. 
Published: November 2006

AbstractAmmonia negative ion CI‐MS was applied to analyze the M.W. distribution and regioisomeric structure of TAG in cocoa butter and in cocoa butter equivalents. The M.W. distribution results obtained for a reference cocoa butter were consistent with corresponding results obtained in an intercomparison study by chromatographic methods. Minor but statistically significant differences were observed when proportions of the three major M.W. species (52∶1, 54∶1, and 50∶1; acyl carbon number/number of double bonds) in a mixture of nine cocoa butters and in mixtures containing 10 or 20% (w/w) of specific cocoa butter equivalents were compared. Tandem MS was used to determine the regioisomeric structure of the three major TAG M.W. species in cocoa butter and in cocoa butter equivalents. The regioisomeric structure in cocoa butter and in all the equivalents analyzed were nearly identical, oleic acid being located primarily in the sn‐2 position. These results cannot be exploited in detecting added foreign fats in this case. However, the present study shows that useful TAG composition data, which may be used to detect foreign fats in cocoa butter by applying chemometric data evaluation, can be obtained by MS in a significantly shorter time compared to chromatographic methods.
Ozonization of phenols from Anacardium occidentale (cashew)
Authors: Graham Madeline B. , Tyman H. P. 
Published: November 2006

AbstractThe phenolic lipid components cardanol and cardol, obtained from heat‐processed technical cashew nutshell liquid from Anacardium occidentale, and anacardic acid from the natural product, each containing monoene, diene, and triene constituents, were ozonized. The ozonides were reduced chemically and catalytically to give 8‐(3‐hydroxyphenyl)octanal, 8‐(3,5‐dihydroxyphenyl)octanal, and 8‐(3‐hydroxy‐2‐carboxyphenyl)octanal, respectively, together with formaldehyde, malondialdehyde, butanal, and heptanal in each case. Reduction of the 8‐(3‐hydroxyphenyl)octanal, which was synthesized from 3‐benzyloxybenzaldehyde, gave 3‐octylphenol. Oxidation of the aldehyde with potassium permanganate gave 8‐(3‐hydroxyphenyl)octanoic acid, and reduction with sodium borohydride yielded 8‐(3‐hydroxyphenyl)octanol. For comparison, the trans‐diols of cardanol were prepared by treatment of cardanol with peroxyformic acid and cleaved by periodate oxidation to give an alternative route to 8‐(3‐hydroxyphenyl)octanal but in lower yield. Likewise, the cis‐diols were obtained with potassium permanganate and cleaved without isolation to give the same product in lower yield compared with ozonization.
Abilities of some antioxidants to stabilize soybean oil in industrial use conditions
Authors: Ruger Christopher W. , Klinker Eric J. , Hammond Earl G. 
Published: November 2006

AbstractAntioxidants, chelators, and alcohols were screened at 0.01 and 1.28% by weight for their ability to delay viscosity increase in soybean oil in the presence of metallic colloidal copper and iron at 105°C with air flowing through the sample. Most substances did not significantly enhance the effect of the natural tocopherols in the soybean oil at 0.01%. A few substances were mildly prooxidant, and a few delayed the increase in viscosity significantly. TBHQ at 0.01% was the best antioxidant of those tested. At 1.28% ascorbyl palmitate, BHT, hydroquinone, and TBHQ increased the stability significantly. Again, TBHQ was the most effective. As measured by viscosity increase to 150 CP, TBHQ increased stability about five times over that of soybean oil controls.
Rheological and thermal properties of soybean oils with modified FA compositions
Authors: Wang Tong , Briggs Jenni L. 
Published: November 2006

AbstractRheological and thermal properties of five soybean oils with modified FA compositions were studied. Viscosity decreased with increasing temperature at different rates for the different oils. Oil with a high‐oleic acid content had higher viscosity and a greater rate of change than did oils with typical FA compositions, oil with low‐saturated FA or low‐linolenic acid content, or oil from lipoxygenase‐free soybeans. The melting and crystallization behaviors of the oils were examined using DSC. The high‐oleic acid oil and the oil with low‐saturated FA content had different DSC profiles compared with the other oils. Specific heat capacities of oils were estimated using a mathematical model; the high‐oleic acid oil had a higher specific heat value, and the low‐saturated FA oil had a lower value than did the other oils.
Effect of water washing on the reduction of surface total lipids and FFA on milled rice
Authors: Monsoor M. A. , Proctor A. 
Published: November 2006

AbstractA simple method for removing total lipids from the rice surface by water washing is described for brewing operations, where small FFA levels can have a considerable effect on end‐product flavor quality. Commercially milled (first‐, second‐, and third‐break) rice was washed with deionized water with constant stirring for 5 and 10 min. About 60 to 80% of total surface lipids were removed by water washing, with a reduction of FFA and conjugated dienes (CD) relative to unwashed control samples. The total surface FFA content of first‐, second‐, and third‐break milled rice was reduced by more than 50% of the original value by washing. Increases in FFA and CD in washed rice after 7 d of storage at 37°C and 70% RH were much lower than those of unwashed controls, in which FFA and CD development was considerably greater and reached brewing quality. Water washing may be a practical means of reducing off‐flavor development in milled rice.
Solubility in supercritical carbon dioxide of the predominant carotenes of tomato skin
Authors: Gómez‐Prieto M. S. , Caja M. M. , Santa‐María G. 
Published: November 2006

AbstractSolubilities in supercritical carbon dioxide of the predominant carotenes in tomato skin were measured. The use of a polymeric C30 RP‐HPLC column to analyze the tomato extract made it possible to separate several geometric isomers from each carotene extracted. The Chrastil model was used to assign a solubility equation to each extracted carotene. Different solubility behaviors in supercritical carbon dioxide were shown by carotenes depending on their nature and configuration. The most soluble carotene was all‐trans‐phytoene and the least soluble was all‐trans‐lycopene. Significant differences in solubility were observed between the trans and cis isomers of lycopene. The results indicate that a fractionation of the tomato skin carotenes can be achieved by using supercritical CO2 extraction.
Retardation of volatile aldehyde formation in the exhaust of frying oil by heating under low oxygen atmospheres
Authors: Fujisaki Mariko , Endo Yasushi , Fujimoto Kenshiro 
Published: November 2006

AbstractVolatile aldehydes were generated in the exhaust of high‐oleic safflower oil during heating at 180°C by spraying water into atmospheres with four levels of oxygen concentrations (2, 4, 10, and 20%). These aldehydes were quantitatively analyzed by HPLC after the conversion to 2,4‐dinitrophenyl hydrazones. Ten alkanals (C2 through C10), eight 2‐alkenals (C3 through C10) and three 2,4‐alkadienals (C7, C9, and C10) were found. These aldehyde levels were found to be positively correlated with both the heating time and the atmospheric oxygen concentration. The total amounts of aldehydes were the lowest in the oil heated in an atmosphere with 2% O2, and corresponded to 1/10 of those in the atmosphere with 20% O2. Acrolein was not found in oils heated in the atmosphere with 2% oxygen. These results suggest that frying in atmospheres with low oxygen levels can effectively decrease the generation of volatile aldehydes in the exhaust.
Kinetics of the decomposition of total aliphatic waxes in olive oil during deodorization
Authors: Tubaileh R. M. , Graciani Constante M. M. , Camacho M. Léon , López A. López , Constante E. Graciani 
Published: November 2006

AbstractChanges in the content of aliphatic waxes during industrial deodorization and/or physical refining of bleached olive oil were studied in an experimental discontinuous pilot plant of 250 kg deodorizer using nitrogen as stripping gas in place of steam. The kinetic constants for the decomposition of waxes during the deodorization process were determined. The reaction orders studied are zero (or can be considered zero) within the working interval. The values of rate constants, activation energy, frequency factor, increment of activation Gibbs free energy, activation enthalpy, and activation entropy are established.
Characterization of sterols in refined borage oil by GC‐MS
Authors: Wretensjö Inger , Karlberg Bo 
Published: November 2006

AbstractBorage oil sterols were isolated by TLC and characterized using GC and GC‐MS. Several diunsaturated Δ5‐sterols, some of them not previously recorded in vegetable oils, were found. Of these, 24‐methylcholesta‐5,23‐dienol and 24‐ethylcholesta‐5,23‐dienol could be useful markers for borage oil. Two other diunsaturated Δ5‐sterols that are rarely found in vegetable oils, 24‐methylcholesta‐5,24(25)‐dienol and 24‐ethylcholesta‐5,24(25)‐dienol, were identified. The diunsaturated C‐24(28)‐sterol, isofucosterol, was also found, as well as the monounsaturated Δ5‐sterols campesterol and sitosterol. These are normally present in vegetable oils, which makes them unsuitable as markers for borage oil.
Determination of slip melting point in palm oil blends by partial least squares and principal component regression modeling of FTIR spectroscopic data
Authors: Setiowaty G. , Man Y. B. Che 
Published: November 2006

AbstractThe determination of slip melting point (SMP) in refined, bleached, and deodorized palm oil is a common and regular requirement in the manufacture of this oil. An FTIR spectrometer in the mid‐IR wavelength region (4000‐750 cm−1) can provide the basis for a suitable on‐line and off‐line quantitative analytical methodology if used with a suitable calibration model. In this study, by using data from selected regions, the calibration models, including principal component regression and partial least squares regression, have been examined and evaluated for efficacy in determining SMP directly in palm oil blends. Results indicate that orthogonal models using selected wavelength data offer superior predictive performance.
Phosphorus‐to‐phospholipid conversion factors for crude and degummed sunflower oils
Authors: Carelli Amalia A. , Ceci Liliana N. , Crapiste Guillermo H. 
Published: November 2006

AbstractPhospholipid composition and phosphorus content of several crude and degummed sunflower oils were measured in order to compare theoretical and experimental factors used to convert phosphorus content to phospholipid content. Differences in phospholipid content between sunflower oils obtained by different extraction and degumming methods were also considered. From FA and phospholipid compositions, average theoretical conversion factors of 24.7 and 23.0 were found for crude and degummed sunflower oils, respectively. The experimental conversion factor for degummed oils was in good agreement with the theoretical value. In contrast, fitted experimental factors were significantly lower for crude oils. The differences could be attributed to phosphorus from sources other than phospholipids and to the presence of minor phospholipids not quantified by chromatographic analysis. The relative phospholipid concentrations of oils depended on the method of extraction and the type of degumming. Solvent‐extracted oils had a higher total phospholipid content, being generally more concentrated in PC and PE. The content of nonhydratable phospholipids was relatively low; acid or enzymatic degumming removed 40 to 70% of these phospholipids.
Extraction and analysis of ceramides from internal wool lipids
Authors: Coderch L. , Fonollosa J. , Martí M. , Garde F. , de la Maza A. , Parra J. L. 
Published: November 2006

AbstractThis study sought to obtain internal wool lipid extracts rich in ceramides from different wool types. Extraction methods, i.e., Soxhlet extraction with different organic solvents and supercritical fluid extraction with CO2 using several polarity modifiers such as MeOH or EtOH, were optimized. The internal wool lipid content varied from 0.2 to 1.9% (based on wool weight) with a ceramide content ranging from 15 to 30% (based on extract weight). The Spanish and Russian Merino wool extracts were the richest in ceramide compounds. TLC‐FID was used to quantify the different internal wool lipid extracts. A new experimental protocol that enabled us to identify most of the different ceramide types is presented. These internal wool lipid extracts, especially the ones with a high ceramide content, may be regarded as an alternative source of animal ceramides, which could be of value in the cosmetic and dermopharmaceutical industries.
Hydrogenated vegetable oils as candle wax
Authors: Rezaei Karamatollah , Wang Tong , Johnson Lawrence A. 
Published: November 2006

AbstractPartially hydrogenated soybean oil, referred to as soywax, is gaining attention as a renewable and biodegradable alternative to paraffin wax for use in candles. However, current soywax candles suffer from several problems, especially poor melting and solidification properties. Fully hydrogenated soybean oil exhibits improved melting properties but owing to its fragile texture, it is not yet acceptable in most candle applications. In the present work, KLXTM (a wax composed of fractionated hydrogenated soy and cottonseed oils) was used as a base material for candles, and the effects of additives such as hydrogenated palm oil (HPO), FFA, and paraffin on the textural and combustion properties were evaluated. Melting and solidification profiles of KLX were better than those of fully hydrogenated soy oil. Adding FFA improved the solidification properties of KLX candles. Adding paraffin improved the compressibility of the wax, while HPO addition decreased hardness and compressibility. Changing the candle diameter and/or wick size along with changing the wax composition resulted in candles with desirable quality attributes.
Stereospecific analysis of TAG from sunflower seed oil
Authors: Boukhchina Sadok , Gresti Joseph , Kallel Habib , Bézard Jean 
Published: November 2006

AbstractStereospecific analysis of TAG from a sunflower seed oil of Tunisian origin was performed. The TAG were first fractionated according to chain length and degree of unsaturation by RP‐HPLC. The four major diacid‐ and triacid‐TAG fractions were palmitoyldilinoleoyl‐glycerol, dioleoyllinoleoylglycerol, oleoyldilinoleoylglycerol, and palmitoyloleoyl‐linoleoyl‐glycerol, amounting to 7.2, 16.6, 29.5, and 12 mol%, respectively. The TAG of the four fractions were individually submitted to stereospecific analysis, using a Grignard‐based partial deacylation, separation of sn‐1,2(2,3)‐DAG from sn‐1,3‐DAG by boric acid‐impregnated silica gel TLC plates, conversion of the sn‐1,2(2,3)‐DAG to their 3,5‐dinitrophenylurethane (DNPU) derivatives, fractionation of DNPU derivatives by RP‐HPLC, resolution of the DNPU‐DAG by HPLC on a chiral column, transmethylation of each sn‐DNPU‐DAG fraction, and analysis of the resulting FAME by GC. The data obtained were used to determine the triacyl‐sn‐glycerol composition of the main TAG of the oil. Fifteen triacyl‐sn‐glycerols were identified and quantified, representing, along with the monoacid‐TAG, trilinoleoylglycerol and trioleoylglycerol, more than 90% of the total oil TAG. The two major triacyl‐sn‐glycerols were trilinoleoyl‐glycerol and 1‐linoleoyl‐2‐linoleoyl‐3‐oleoyl‐glycerol (18.6 and 18.5% of the total, respectively). Results clearly identified linoleic acid as the major FA at the sn‐2 position, whereas oleic and palmitic acids were the major FA at the sn‐3 position. The sn‐1 position was occupied to nearly the same extent by linoleic and oleic acids, and to a greater extent by palmitic acid, which was practically absent at the sn‐2 position.
Partial purification ofNigella sativaL. Seed lipase and its application in transesterification reactions
Authors: Tuter Melek , Secundo Francesco , Riva Sergio , Aksoy H. Ayşe , Ustun Guldem 
Published: November 2006

AbstractNigella sativaL. seed lipase isolated from defatted seeds was partially purified and used as catalyst in transesterification reactions. Purification of an ammonium sulfate‐precipitated sample (at 35% saturation,Nigella PL) by DEAE ion‐exchange chromatography increased the specific activity from 13.9 to 156.7 U/mg protein.Nigella PLandNigella CPL(the partially purified enzyme sample obtained by DEAE ion‐exchange chromatography) catalyzed the transesterification of vinyl acetate with octanol, with racemic sulcatol (6‐methyl‐5‐hepten‐2‐ol), and with racemictrans‐sobrerol (trans‐p‐menth‐6‐ene‐2,8‐diol) in different organic solvents. Both activity and enantioselectivity of the enzyme samples used for these biotransformations were affected by the nature of the organic solvent.
Phase equilibrium and crystallization behavior of mixed lipid systems
Authors: Liang Baomin , Shi Yuping , Hartel Richard W. 
Published: November 2006

AbstractAs complex lipid systems, the phase and crystallization behavior of mixtures of a high‐melting milk fat fraction with a low‐melting milk fat fraction or canola oil was studied. A turbidity technique was developed to estimate solubility and metastability conditions of these lipid mixtures. Both solubility and metastability of the high‐melting milk fat fraction in liquid lipids increased exponentially with temperature. At a given equilibration temperature, liquid phases and solid fractions with nearly identical melting profiles and TAG compositions were obtained regardless of the original concentration of the lipid mixture. The maximum melting temperature (MMT), as measured by DSC, of the liquid phase increased dramatically in the equilibrium temperature range of 27.5–35.0°C but did not change at temperatures below and above this range (down to 25.0°C and up to 40°C in this study). The content of long‐chain TAG (C46−C52) increased and short‐chain TAG (C36−C40) decreased in the liquid phases as the equilibrium temperature increased. A plot of the TAG group ratio (i.e, long‐short‐chain TAG) vs. equilibrium temperature was generated to illustrate the phase behavior of the complex lipid system and to represent a solubility curve, from which the supersaturation level for crystallization kinetics was determined. Higher supersaturation and lower temperature resulted in higher nucleation and crystallization rates. Compared to the system with a low‐melting milk fat fraction, mixtures of the high‐melting milk fat fraction with canola oil had higher nucleation and crystallization rates due to the lower solubility found for this system.