bluuebunny/crossref_metadata_2025_split huggingface dataset:
Determination of peroxide value in thermally oxidized crude palm oil by near infrared spectroscopy
Authors: Moh M. H. , Che Man Y. B. , van de Voort F. R. , Abdullah W. J. W. 
Published: May 2007

AbstractA near infrared (NIR) spectroscopic method was developed to measure peroxide value (PV) in crude palm oil (CPO). Calibration standards were prepared by oxidizing CPO in a fermentor at 90°C. A partial least squares (PLS) calibration model for predicting PV was developed based on the NIR spectral region from 1350 to 1480 nm with reference to single‐point baseline at 1514 nm. The optimization of calibration factors was guided by the predicted residual error sum of squares test. The standard error of calibration obtained was 0.156 over the analytical range of 2.17–10.28 PV and the correlation coefficient (R2) was 0.994. The method was validated with an independent set of samples which was prepared in the same manner on a different day. A linear relationship between the American Oil Chemists’ Society and the NIR methods was obtained with R2 of 0.996 and standard error of performance of 0.17. This study has demonstrated that the prediction of PV in the NIR region is possible. The method developed is rapid, with total analysis time less than 2 min, is environmentally friendly, and its accuracy is generally good for quality control of CPO.
Development of calibration equations to predict oil content and fatty acid composition in brassicaceae germplasm by near‐infrared reflectance spectroscopy
Authors: Velasco Leonardo , Goffman Fernando D. , Becker Heiko C. 
Published: May 2007

AbstractThe use of nondestructive analytical methods is critical for the evaluation of very small seed samples such as those from germplasm collections. The objective of this study was to evaluate the potential of near‐infrared reflectance spectroscopy (NIRS) for the simultaneous analysis of seed oil content and concentration of major fatty acids in intact‐seed samples of the family Brassicaceae. A total of 495 samples from 56 genera and 128 species were analyzed by NIRS. The fatty acid composition of the seed oil was determined in all the samples by gas‐liquid chromatography (GLC). The total seed oil content was determined by solvent extraction in 129 samples from 22 genera. Calibration equations for oil content (n=97) and individual fatty acids (n=410) were developed and tested through external validation with the samples not included in the calibration sets. The calibration equations for oil content (r2=0.97 in validation) and concentrations of C18:1 (r2=0.93), C18:3 (r2=0.95), and C22:1 (r2=0.94) showed very good performance and provided reliable estimations of these traits in the samples of the validation set. The calibration equations for C16:0, C18:0, and C18:2 content were less reliable, with r2 from 0.67 to 0.73. There was practically no response of NIRS to differences in C20:1 (r2=0.31). These results demonstrated that the oil content and concentrations of C18:1, C18:3, and C22:1 can be estimated reliably within the family Brassicaceae by using NIRS calibration equations integrating broad taxonomic variability.
Changes in flax (Linum usitatissimum L.) seed lipids during germination
Authors: Wanasundara P. K. J. P. D. , Wanasundara U. N. , Shahidi F. 
Published: May 2007

AbstractFlax (Linum usitatissimum L.) seeds were germinated for 8 d under laboratory conditions, and changes in their lipid fraction were studied by various chemical and chromatographic methods. Total lipid content of the seeds was reduced fourfold at the end of the 8‐d germination period as compared to ungerminated seeds on a fresh weight basis. The neutral lipids comprised the major fraction of seed lipids, and triacylglycerols predominated over all other lipid components even during the germination period. Both the spectrophotometric and thin‐layer chromatography‐flame‐ionization detection methods of quantification showed a considerable increase in the content of free fatty acids. The glycolipid fraction of lipids increased, but the phospholipid fraction exhibited only minor changes. Lipase activity of flaxseed increased at the beginning of germination and then remained constant until the fifth day. Phosphatidylcholine was the major phospholipid of flaxseed lipids, and its content was reduced during the germination. The contents of lysophosphatidylcholine and phosphatidic acid increased from negligible amounts to 46% of the total phospholipids. Linolenic, linoleic, and oleic acids, respectively, were the predominant fatty acids of all the lipid fractions of flaxseed, and remained unchanged during the germination period. The glycolipid fraction had the lowest content of polyunsaturated fatty acids. Fatty acids C14:0, C20:0, C24:0, C20:1, C22:1, and C20:5 appeared after d 2 of germination in neutral, glyco‐ and phospholipid fractions.
Separation and characterization of peanut phospholipid molecular species using high‐performance liquid chromatography and fast atom bombardment mass spectrometry
Authors: Singleton J. A. , Ruan M. , Sanford J. H. , Haney C. A. , Stikeleather L. F. 
Published: May 2007

AbstractTotal lipid extracts from peanut seed were separated on a silica column into a triacylglycerol fraction and a polar lipid fraction by high‐performance liquid chromatography (HPLC). The polar fraction containing the phospholipids was retained on the precolumn, and the triacylglycerol fraction was eluted to a waste flask by a special valve arrangement. Phospholipids were eluted from the precolumn and separated into various classes on a silica analytical column. Each phospholipid class was manually collected and subsequently subjected to reversed‐phase HPLC in tandem with a fast atom bombardment mass spectrometer. Phosphatidylethanolamine was separated into five molecular species. Phosphatidylinositol and phosphatidylcholine were each separated into six molecular species.
Characterization of phospholipids from glyphosate‐tolerant soybeans
Authors: List G. R. , Orthoefer F. , Taylor N. , Nelsen T. , Abidi S. L. 
Published: May 2007

AbstractThe phospholipids from three control and two glyphosate‐tolerant soybean cultivars were isolated by extraction of soy flakes with hexane and characterized after separation by high‐pressure liquid chromatography. In addition, several lots of commercial fluid lecithin were analyzed and the results were compared to values published in the literature. Phosphatidylcholine, phosphatidylethanolamine, phosphatidylinositol, and phosphatidic acid were identified as major components in these cultivars and in the commercial lecithin samples. The results showed that glyphosate‐tolerant soybeans yield lecithin comparable and equivalent to conventional soybean cultivars.
Lecithin gum rheology and processing implications
Authors: Lambourne David , Covey Geoff H. , Chai Eugene , Dunstan David 
Published: May 2007

AbstractThe rheology of canola, sunflower, and soybean lecithin gum was examined by studying samples of different moisture contents produced in a batch evaporator (70°C, 0.1 atm). Soybean lecithin was found to have the lowest viscosity, approximately 10 poise (100 s−1, 70°C), compared to canola and sunflower lecithin with viscosities of approximately 90 and 90,000 poise, respectively. The high sunflower viscosity was attributed to the presence of long‐chain waxes. Lecithin gum was shown to change from a Bingham (water continuous phase) to a pseudoplastic (oil continuous phase) type fluid as the moisture content of the lecithin gum decreased. The viscosity maxima occurred between 6.9 and 19.3% moisture content (100 s−1), with the variation found to be related to the oil/water ratio of the system. Rheological results indicated that vertical scraped surface evaporator design could be optimized through the addition fluidizing of agents prior to the evaporator and/or increased heating at the evaporator outlet.
Deodorization of vegetable oils. Part I: Modelling the geometrical isomerization of polyunsaturated fatty acids
Authors: Hénon G. , Kemény Zs. , Recseg K. , Zwobada F. , Kovari K. 
Published: May 2007

AbstractLaboratory‐scale treatments of canola oils similar to deodorization were carried out by applying the following conditions: reduced pressure with nitrogen or steam stripping at different temperatures ranging from 210 to 270°C for 2–65 h. The formation of the group of trans linolenic acid isomers follows a first‐order reaction and the kinetic constant varies according to the Arrhenius’ law. Similar results were observed for the trans isomerization of linoleic acid. Based on these experiments, a mathematical model was developed to describe the isomerization reaction steps occurring in linoleic and linolenic acids during deodorization. The calculated degrees of isomerization are independent of the composition of the oil but related to both time and temperature of deodorization. The degree of isomerization of linolenic acid is unaffected by the decrease of this acid content observed during the deodorization. Deodorization at about 220–230°C appears to be a critical limit beyond which the linolenic isomerization increases very strongly. The newly established model can be a tool for manufacturers to reduce the total trans isomer content of refined oils, and was applied to produce a special selectively isomerized oil for a European Nutritional Project.
Acetone‐stable nanofiltration membranes in deacidifying vegetable oil
Authors: Zwijnenberg H. J. , Krosse A. M. , Ebert K. , Peinemann K. V. , Cuperus F. P. 
Published: May 2007

AbstractThe separation of different vegetable oil/solvent mixtures with two types of nanofiltration membranes was studied. One type had a PEBAX [poly(amide‐b‐ether) copolymer] top layer, and the other had a cellulose‐type top layer. These membranes were stable in acetone, ethanol, 2‐propanol, and hexane, all important to the oleochemical industry. Permeabilities were highest for acetone, ±140 L/m2 · h · MPa, and lowest for hexane, which had negligible flux at 2 MPa. Permeabilities decreased with increasing triglyceride or free fatty acid (FFA) concentration. Rejection of triglycerides was constant over the concentration range tested, about 80–95%±5%, depending on the type of membrane used. These properties make membranes applicable for separating triglycerides from acetone by enhancing acetone recovery. Deacidification of triglycerides and FFA mixtures was possible (e.g., fatty acids were retained less than triglycerides). The permeate consisted almost entirely of fatty acids in acetone, and only small traces of triglycerides were found. This makes it feasible to selectively remove the fatty acids and reduce loss of triglycerides normally associated with deacidification.
Model for a cascade continuous epoxidation process
Authors: Hang Xiaomin , Yang Hong 
Published: May 2007

AbstractA steady‐state mathematical model was developed to analyze the performance of a cascade continuous epoxidation process that was applied to the epoxidation of unsaturated compounds with in‐situ‐formed performic acid. The model equations were nonlinear, and the model prediction was calculated by solving the model equations using a numerical solution procedure. The experimental results supported the model prediction in that good agreement between the model predictions and experimental results was achieved. The model is necessary for precise operation control, process estimation, and operating parameter optimization and regulation, and will provide a theoretical foundation and research method for automatic control and engineering scale‐up.
Ruthenium‐catalyzed metathesis of vegetable oils
Authors: Refvik M. D. , Larock R. C. , Tian Q. 
Published: May 2007

AbstractA new process for the acyclic diene metathesis of vegetable oils utilizing Grubbs’ ruthenium catalyst (Cy3P)2Cl2Ru = CHPh has been developed. The higher molecular weight oligomers obtained can be separated from the unreacted oil and the lower molecular weight alkene by‐products easily. The reaction proceeds in the absence of solvent, with very low catalyst concentrations (0.1 mole %) under moderate temperatures and low pressures. This process does not require the stringent exclusion of water and oxygen that the previous method (Me4Sn plus WCl6) required. Low pressures appear to favor polymerization by removing the alkene by‐products. The metathesis reaction has been shown to be effective for many unsaturated vegetable oils, although some cases require oil pretreatment with silica gel. This process is effective on a 2–200 g scale. Chromatographic separation and characterization of metathesized soybean oil indicate that the process involves intermolecular and intramolecular carbon‐carbon double‐bond formation.
The chemistry of metathesized soybean oil
Authors: Refvik M. D. , Larock R. C. 
Published: May 2007

AbstractNew materials derived from metathesized soybean oil have been prepared and characterized. Thermal polymerization of metathesized soybean oil in the presence of air results in yellow, brittle gels. These materials display a curious tendency to produce audible popping sounds when exposed to chlorinated organic solvents, such as chloroform or dichloromethane. Complete hydrogenation of metathesized soybean oil has been accomplished in excellent yields utilizing 10% palladium on carbon in dichloromethane. A new, very mild, effective epoxidation procedure for soybean oil, utilizing methyltrioxorhenium (VII) (MTO) and pyridine as the catalyst system and hydrogen peroxide as the oxidant, has been developed. This epoxidation reaction affords excellent yields of epoxidized soybean oil with some control of the degree of epoxidation at very low MTO concentrations (< 0.5 mol%). This reaction is also very effective for the epoxidation of metathesized soybean oil to higher molecular weight epoxidized soybean oil materials.
Synthesis of tetrahydrofuran ring containing oligoethylene glycol ethers from the seed oil of Vernonia anthelmintica
Authors: Singh Sukhprit , Mahajan Sonia , Kaur Harpal 
Published: May 2007

AbstractA tetrahydrofuran ring containing oligoethylene glycol ethers has been synthesized from the seed oil of Vernonia anthelmintica. The seed oil was reacted with mono‐, di‐, and triethylene glycols in the presence of boron trifluoride etherate, followed by saponification and esterification (MeOH/H+). The oligoethylene glycol ethers thus obtained were epoxidized with perbenzoic acid. The 9,10‐epoxy oligoethylene glycol ethers so formed were intramolecularly cyclized in dry benzene using boron trifluoride etherate as a catalyst to yield the tetrahydrofuran ring containing oligoethylene glycol ethers; methyl 9,12‐epoxy, 10‐hydroxy‐13‐[2‐hydroxyethyl‐1‐oxy]; methyl 9,12‐epoxy,10‐hydroxy‐13‐[2‐hydroxy‐3‐oxapentyl‐1‐oxy] and methyl 9,12‐epoxy,10‐hydroxy‐13‐[8‐hydroxy‐3,6‐dioxaoctyl‐1‐oxy]octadecanoates, respectively.
Thermal analysis of alternative diesel fuels from vegetable oils
Authors: Dunn Robert O. 
Published: May 2007

AbstractThe relatively poor cold‐flow properties of monoalkyl esters of vegetable oils and animal fats (biodiesel) present a major obstacle to their development as alternative fuels and extenders for combustion in direct injection compressionignition (diesel) engines. In this work, differential scanning calorimetry (DSC) heating and cooling curves of methyl soyate (SME), methyl tallowate (TME), SME/TME admixtures, and winterized SME were analyzed. Completion of melt, crystallization onset (Onset), and other temperatures corresponding to melting and freezing peaks were correlated to predict cloud point (CP), pour point (PP), cold filter plugging point (CFPP), and low‐temperature flow test (LTFT) data. Effects of treating methyl esters with cold‐flow improvers were examined. Low‐temperature flow properties of biodiesel may be accurately inferred from subambient DSC analyses of high‐melting or freezing (β‐form) peaks. The temperature of maximal heat flow for freezing peaks gave the best accuracy for predicting CP, PP, and CFPP, while freezing point gave the best accuracy for predicting LTFT. Onset also gave good correlations with respect to predicting PP, CFPP, and LTFT. Cooling scan parameters were more reliable than heating scan parameters.
Plastic performance of soybean protein components
Authors: Sun Xiuzhi Susan , Kim Hak‐Ryang , Mo Xiaoqun 
Published: May 2007

AbstractSoybean proteins recently have been considered as petroleum polymer alternatives in the manufacture of adhesives, plastics, and various binders. The objective of this work was to characterize the plastic performance of soybean protein components during molding processes. Two major soybean protein fractions, 7S‐rich globulin (7S‐RG) and 11S‐rich globulin (11S‐RG) were separated from defatted soybean flour, and their purity was examined by sodium dodecyl sulfate‐polyacrylamide gel eletrophoresis and high‐performance liquid chromatography. The thermal transition properties of the two fractions at 10% moisture content were 137.6°C for 7S and 163°C for 11S, as analyzed using differential scanning calorimetry (DSC). Plastics were prepared using a hot press at various molding temperatures that were selected based on the proteins’ thermal transition temperatures obtained by DSC. The plastics were evaluated for mechanical properties, water absorption, and microstructure. The plastics prepared with temperatures at or close to the thermal transition temperature showed a smooth, uniform, and complex structure. Results showed that the plastics made from 11S‐RG at its thermal transition temperature were stronger (35 MPa) and had lower water absorption than those made from 7S‐RG at 145°C (26 MPa). The plastics made from the 7S‐ and 11S‐RG mixture had the highest tensile strength (39 MPa) and medium water absorption compared to those made from 7S‐ and 11S‐RG alone. These mechanical properties and water absorption behaviors were significantly affected by molding temperatures. The results obtained from this research indicated that interaction between 7S‐ and 11S‐RG could occur during molding and that thermal transition temperature played an important role in thermal processing of soybean proteins.
Hydrocarbons as markers for identifying postirradiated peanuts
Authors: Park J. Y. , Hwang K. T. 
Published: May 2007

AbstractHydrocarbons produced by γ‐radiation of peanuts were analyzed to determine the relationship between irradiation and production of hydrocarbons, and the use of hydrocarbons as markers for identifying postirradiated peanuts. Hydrocarbons in peanuts were determined by a sequential procedure of lipid extraction by hexane, Florisil column chromatography, and gas chromatography. Hydrocarbons C17:1, C16:2, C17:2, and C16:3 were easily detected in peanuts irradiated at 0.5 kGy or higher, but not in unirradiated ones. The hydrocarbons were minimally changed by roasting the irradiated peanuts and were not detected in unirradiated roasted peanuts.
Oxidation of linoleic acid in emulsions: Effect of substrate, emulsifier, and sugar concentration
Authors: Ponginebbi L. , Nawar W. W. , Chinachoti P. 
Published: May 2007

AbstractLinoleic acid oxidation in oil‐in‐water emulsions stabilized by a nonionic surfactant (Tween‐20) was studied. The emulsion composition was varied at a constant oil droplet size. Lipid oxidation was measured as a function of time in the presence of a catalyst (FeSO4 corbic acid) by two methods: gas chromatographic determination of residual substrate and ultraviolet‐visible spectrophotometric determination of conjugated dienes. Rate of oxidation was influenced by the emulsion composition (relative concentrations of substrate and emulsifier) and especially by the partition of the emulsifier between the interface and water phase. Concentrations of emulsifier exceeding the critical micelle concentration protected the fatty acid against oxidation. Excess surfactant formed micelles and mixed micelles with linoleic acid, which retarded oxidation by diluting the substrate or perhaps by replacing linoleic acid at the interface, making it less accessible to radical attack. The addition of sucrose also had a protective effect, but only up to a certain concentration, indicating the effect may involve factors other than viscosity.
Antioxidant activity of flavonol aglycones and their glycosides in methyl linoleate
Authors: Hopia Anu , Heinonen Marina 
Published: May 2007

AbstractThe antioxidant activities of the flavonol aglycones, quercetin and myricetin, and their selected glycosides were compared in bulk methyl linoleate oxidized at 40°C. Methyl linoleate hydroperoxide formation, hydroperoxide isomer distribution, and ketodiene formation were followed by using high‐performance liquid chromatography (HPLC) analysis. The aglycones, quercetin and myricetin, were consistently more active in bulk methyl linoleate than their glycosides and more active than α‐tocopherol at 500 and 1000 µM. At 50 µM, the order of activity was myricetin > α‐tocopherol > quercetin, and the order of activity of quercetin and its derivatives was quercetin > quercitrin > isoquercitrin > rutin. Myricitrin was slightly less active than myricetin. The sugar moiety was shown to have a marked effect on the antioxidant activity of flavonols. The rhamnoside derivatives, quercitrin and myricitrin, both possessed activity close to that of their corresponding aglycones. The different activities of glycosides could be partly explained by different solubilities and by differences in oxidizability of glycosides containing a monosaccharide or disaccharide at the C3 position. The effect on hydroperoxide isomer distribution indicates that α‐tocopherol was a more effective hydrogen donor than flavonoids, although flavonoids were more effective in inhibiting oxidation of methyl linoleate.
Immobilization of porcine pancreatic lipase on celite for application in the synthesis of butyl butyrate in a nonaqueous system
Authors: de Castro Heizir F. , de Oliveira Pedro C. , Soares Cleide M. F. , Zanin Gisella M. 
Published: May 2007

AbstractFor immobilization of lipase, the use of a porous support material is recommended so that suitable amounts of lipase can be spread on a surface area without conformational changes. In this work, porcine pancreatic lipase was deposited on Celite, either by direct binding from aqueous solution or by deposition from aqueous solution by the addition of organic solvent. The influence of the immobilization procedure on the activities of the derivatives has been studied regarding their ability to synthesize butyl butyrate. The reaction rates were compared with the rate of esterification with free lipase. Better properties were displayed when the immobilized lipase form was prepared in an apolar solvent such as hexane. Under suitable reaction conditions, esterification yields as high as 90% were attained. Batch operational stability tests indicated that no enzyme deactivation occurs after 15 consecutive batches of 24 h each.