bluuebunny/crossref_metadata_2025_split huggingface dataset:
Differential scanning calorimetry of water buffalo and cow milk fat in mozzarella cheese
Authors: Tunick Michael H. , Malin Edyth L. 
Published: May 2007

AbstractThe thermal profiles of the fat in mozzarella cheeses made from cow milk (CM) and water buffalo milk (WBM) were obtained by differential scanning calorimetry (DSC). The DSC curves of mozzarella cheese made from WBM were distinguishable from those of CM. The curves resembled those of the corresponding milk fats and could be divided into low‐, medium‐, and high‐temperature melting regions. The valley in the curve between the low‐ and medium‐temperature melting regions was at 10.8°C in WBM cheese and below 10°C in CM cheese. In the WBM cheese, the area of the low‐melting region was larger than the area of the medium‐temperature melting region, but the two areas were equal in the CM cheeses. Mixtures of the two cheeses exhibited temperature and area values between those of the pure cheeses. Milk‐fat mixtures showed similar behavior. The contrasting DSC melting profiles provide a way of distinguishing between the two mozzarella cheese types and for detecting mixtures of the two fats in mozzarella cheese.
Odor and flavor contribution of 2‐pentyl pyridine to soy protein isolates
Authors: Boatright W. L. , Crum A. D. 
Published: May 2007

AbstractTotal lipid extracts from two commercial soy protein isolates (SPI) were subjected to analyses by gas chromatography/olfaction by using capillary columns with stationary phases of three different polarities. With Kovats indices to identify the location of the odorous compounds on chromatograms produced with the same lipid extracts by gas chromatography/mass spectroscopy, the corresponding mass spectra of clearly distinguishable odors were examined. Compounds, tentatively identified by their mass spectra, were confirmed by retention times (on all three stationary phases), odor intensity, and odor description when compared with standards. Major odorous compounds identified included 2‐methyl butyric acid methyl ester, hexanal, butyric acid, and 2‐pentyl pyridine. Subsequent sensory analyses demonstrated that the mean levels of 2‐pentyl pyridine found in two SPI (0.28 and 1.01 ppm), combined with its repulsive flavor profile (throat‐catching and grassy in water) and extremely low flavor threshold level (0.000012 ppm), make it a major contributor to the undesirable flavor of SPI. Its mean contents in SPI were 23,333 and 84,167 times greater, respectively, than its flavor threshold. The level of hexanal was 112 and 201 times, respectively, above its flavor threshold, and the level of 2‐pentyl furan in each SPI was 433 and 592 times, respectively, above its flavor threshold, which indicates that these two compounds make relatively minor contributions to the flavor of SPI.
Bishomopinolenic (7,11,14–20:3) acid in pinaceae seed oils
Authors: Wolff Robert L. , Christie William W. , Coakley David 
Published: May 2007

AbstractBishomopinolenic (7,11,14–20:3; BHP) acid has been identified in a sample of pine (Pinus contorta) seed oil by gas‐liquid chromatography‐mass spectrometry of its 4,4‐dimethyloxazoline and picolinyl ester derivatives. Neither 20:3n‐6 nor 18:3n‐6 acids could be detected. The distribution of BHP acid in the seed oils of four conifer families has been established. It only occurred in Pinaceae (Pinus, Abies, Cedrus, Tsuga, Pseudotsuga, Larix, and Picea; 72 species analyzed), where it could reach 0.7% of total fatty acids. It could not be detected in Taxaceae (Taxus baccata), Cupressaceae (Juniperus communis), or Taxodiaceae (Sciadopytis verticillata) seed lipids. It is assumed that BHP acid is the elongation product of pinolenic (5,9,12–18:3) acid, and that, at most, 3% of pinolenic acid is elongated to BHP acid. Consequently, the Δ5‐desaturation would not necessarily be a final step in the biosynthesis of unsaturated polymethylene‐interrupted fatty acids in Pinaceae seeds. Moreover, conifer seeds appear devoid of the Δ6‐desaturase.
Phospholipid fatty acid composition and stereospecific distribution of soybeans with a wide range of fatty acid composition
Authors: Wang Tong , Hammond Earl G. , Fehr Walter R. 
Published: May 2007

AbstractPhospholipid (PL) fatty acid composition and stereospecific distribution of 25 genetically modified soybean lines with a wide range of compositions were determined by gas chromatography and phospholipase A2 hydrolysis. Pl contained an average of 55.3% phosphatidylcholine, 26.3% phosphatidylethanolamine, and 18.4% phosphatidylinositol. PL class proportions were affected by changes in overall fatty acid composition. PL fatty acid composition changed with oil fatty acid modification, especially for palmitate, stearate, and linolenate. Stereospecific analysis showed that saturated fatty acids were primarily located at the sn‐1 position of all PL, and changes of the saturates in PL were largely reflected on this position. Oleate was distributed relatively equally between the sn‐1 and sn‐2 positions. Linoleate was much more concentrated on sn‐2 than on sn‐1 position for all PL. Linolenate was distributed relatively equally at low concentration but preferred sn‐2 position at high concentration.
Determination of the fatty acid composition of the oil in intact‐seed mustard by near‐infrared reflectance spectroscopy
Authors: Velasco L. , Fernández‐Martínez J. M. , De Haro A. 
Published: May 2007

AbstractNear‐infrared reflectance spectroscopy (NIRS) was used to estimate the fatty acid composition of the oil in intact‐seed samples of Ethiopian mustard (Brassica carinata Braun) within a mutation breeding program that produced seeds with variable fatty acid compositions. Five populations, from 1992 to 1996 crops, were included in this study; and NIRS calibration equations for major fatty acids (palmitic, stearic, oleic, linoleic, linolenic, eicosenoic, and erucic) were developed within each single population. Furthermore, global calibration equations, including samples from the five populations, were developed. After external validation, the NIRS technique permitted us to obtain a reliable and accurate nondestructive estimation of the fatty acid composition of the oil, especially for the major acids—oleic, linoleic, linolenic, and erucic. For these, the r2 in external validation was higher than 0.95 by using both single‐and multipopulation equations, and higher than 0.85 for the remaining fatty acids. Moreover, the multipopulation equations provided an accurate estimation of samples from a population not represented in the calibration data set, with values of coefficient of determination in validation (r2) from 0.80 (palmitic and eicosenoic acids) to 0.97 (erucic acid). The ability of NIRS to discriminate among different fatty acid profiles was mainly due to changes within six spectral regions, 1140–1240, 1350–1400, 1650–1800, 1880–1920, 2140–2200, and 2240–2380 nm, all of them associated with fatty acid absorbers. Thus, NIRS can be used to estimate the fatty acid composition of Ethiopian mustard seeds with a high degree of accuracy, provided that calibration equations be developed from calibration sets that include large variability for the fatty acid composition of the oil.
Tocopherol and fatty acid composition of some Indian pulses
Authors: Gopala Krishna A. G. , Prabhakar J. V. , Aitzetmüller K. 
Published: May 2007

AbstractThe tocopherol and tocotrienol composition of the Indian pulses Bengal gram (Cicer arietinum L.), blackgram (Vigna mungo L.), green gram (Vigna radiata L.), and horse gram (Dolichos biflorus L.) were studied. The total tocopherol content ranged from 230 to 1567 mg/100 g fat, while the tocopherol content of the pulses as a whole ranged from 6.76 to 12.54 mg/100 g seed. Presence of such a high amount of tocopherol, both in the oil fraction of Indian pulses and in an oil fraction of a food material, is being reported for the first time. The fatty acid composition of the fat extracted from these pulses showed substantial amounts of unsaturated fatty acids (Bengal gram, 88.7%; black gram, 82.9%; green gram, 64.3%; and horse gram, 66.9%). These pulses contained 3.8 to 49.1% linolenic acid in the fat.
Optimizing headspace sampling temperature and time for analysis of volatile oxidation products in fish oil
Authors: Rørbæk Karen , Jensen Benny 
Published: May 2007

AbstractHeadspace‐gas chromatography (HS‐GC), based on adsorption to Tenax GR®, thermal desorption and GC, has been used for analysis of volatiles in fish oil. To optimize sampling conditions, the effect of heating the fish oil at various temperatures and times was evaluated from anisidine values (AV) and HS‐GC. AV indicated sample degradations at 90°C but only small alterations between 60 and 75°C. HS‐GC showed increasing response with temperature and time. Purging at 75°C for 45 min was selected as the preferred sampling condition for oxidized fish oil.
Oxidative stability of conjugated linoleic acids relative to other polyunsaturated fatty acids
Authors: Zhang A. , Chen Z. Y. 
Published: May 2007

AbstractContrary to current opinion, conjugated linoleic acids (CLA) as a mixture of several isomers have been previously shown to function as prooxidants in the form of free fatty acids and methyl esters in heated canola oil. Furthermore, CLA oxidizes considerably faster than linoleic acid. However, stability of CLA relative to other polyunsaturated fatty acids remains undetermined. The present study was therefore undertaken to examine the relative oxidation rate of CLA compared with that of linolenic acid (LNA), arachidonic acid (AA), and docosahexaenoic acid (DHA) in air at 90°C. CLA, both in the form of free fatty acids and triacylglycerols, were extremely unstable to the same extent as DHA, but they oxidized considerably faster than LNA and AA. The mechanism by which CLA were readily decomposed was probably due to formation of the unstable free‐radical intermediate.
Fatty methyl ester hydrogenation to fatty alcohol part II: Process issues
Authors: Rieke Ross D. , Thakur Deepak S. , Roberts Brian D. , White Geoffrey T. 
Published: May 2007

AbstractFatty alcohols are produced by hydrogenating fatty methyl esters in slurry phase in the presence of copper chromite catalyst at temperatures of 250–300°C and hydrogen pressures of 2000–3000 psi. The fatty methyl ester, catalyst, and hydrogen are fed to the reactor cocurrently. The product slurry is passed through gas‐liquid separators and then through a continuous filtration system for removal of the catalyst. A portion of the used catalyst in crude alcohol is recycled to the hydrogenator. The overall efficiency of the process depends upon the intrinsic activity, life, and filterability of the catalyst. The fatty alcohol producer therefore requires a catalyst with high activity, long life, and good separation properties. The main goal of the present laboratory investigation was to develop a superior copper chromite catalyst for the slurry‐phase process. Two copper chromite catalysts, prepared by different procedures, were tested for methyl ester hydrogenolysis activity, reusability, and filtration characteristics. The reaction was carried out in a batch autoclave at 280°C and 2000–3000 psi hydrogen pressure. The reaction rates were calculated by assuming a kinetic mechanism that was first‐order in methyl ester concentration. The catalyst with the narrower particle size distribution was 30% more active, filtered faster, and maintained activity for several more uses than the catalyst with the broader particle size distribution. X‐ray photoelectron spectroscopy data showed higher surface copper concentrations for the former catalyst.
Effect of fatty acid composition of oils on flavor and stability of fried foods
Authors: Warner K. , Orr P. , Glynn M. 
Published: May 2007

AbstractEffects of fatty acid composition of frying oils on intensities of fried‐food flavor and off‐flavors in potato chips and french‐fried potatoes were determined. Commercially processed cottonseed oil (CSO) and high‐oleic sunflower oil (HOSUN) were blended to produce oils with 12 to 55% linoleic acid and 16 to 78% oleic acid. Analytical sensory panels evaluated french‐fried potatoes and pilot plant‐processed potato chips. Initially, both foods prepared in CSO (16% oleic/55% linoleic acid) had the highest intensities of fried‐food flavor; however, this positive flavor decreased with decreasing levels of linoleic acid. 2,4‐Decadienal in potato chips also decreased with decreasing linoleic acid in the oils. Frying oil stability, measured by total polar compounds (TPC), and oxidative stability of potato chips, measured by volatile compounds, showed that HOSUN (78% oleic acid) produced the lowest levels of TPC and the lowest levels of hexanal and pentanal, indicating greater frying oil stability and oxidative stability of the food. However, fresh potato chips fried in HOSUN had the lowest intensities of fried‐food flavor and lowest overall flavor quality. Fried‐food flavor intensity was the best indicator of overall flavor quality in fresh potato chips. Volatile compounds, TPC, and oxidative stability index directly varied with increasing oleic acid, and were therefore not directly indicative of flavor quality. No oil analysis predicted flavor stability of aged potato chips. Compositions of 16 to 42% oleic acid and 37 to 55% linoleic acid produced fresh fried‐food with moderate fried food flavor intensity, good overall flavor quality, and low to moderate TPC levels (chips only). However, in aged food or food fried in deteriorated oil, compositions of 42 to 63% oleic and 23 to 37% linoleic provided the best flavor stability.
Heated fat‐based oil substitutes, oleic and linoleic acid‐esterified propoxylated glycerol
Authors: Artz William E. , Hansen Steven L. , Myers Michelle R. 
Published: May 2007

AbstractFour oils [triolein, trilinolein, oleic acid‐esterified propoxylated glycerol (EPG‐08 oleate), and linoleic acid‐esterified propoxylated glycerol (EPG‐08 linoleate)], each without added antioxidants, were heated for 12 h/d at approximately 190°C in a small deep‐fat fryer until the polymer concentration exceeded 20%, as determined by high‐performance size‐exclusion chromatography. Increases in the free fatty acid content, total acid value, food oil sensor value, and p‐anisidine value during heating indicated that significant thermal oxidation had occurred in each oil. Capillary supercritical fluid chromatography (SFC) was used to determine the substrate concentration of each oil after each heating interval. The average, apparent first‐order reaction rate constant (as determined by SFC) for trilinolein was 0.0348±0.0034 h−1, while the rate for EPG‐08 linoleate was 0.0253±0.0032 h−1. The average apparent reaction rate constant for triolein was 0.0256±0.0011 h−1, while the rate for EPG‐08 oleate was 0.0252±0.0008 h−1. Triolein contained >20% polymer after 60 h of heating, EPG‐08 oleate contained >20% polymer after 36 h of heating, and both trilinolein and EPG‐08 linoleate contained >20% polymer after 24 h of heating.
A multivariate study of the correlation between tocopherol content and fatty acid composition in vegetable oils
Authors: Kamal‐Eldin Afaf , Andersson Roger 
Published: May 2007

AbstractThe main biochemical function of the tocopherols is believed to be the protection of polyunsaturated fatty acids (PUFA) against peroxidation. A critical question that must be asked in reference to this is whether there is a biochemical link between the tocopherol levels and the degree of unsaturation in vegetable oils, the main source of dietary PUFA and vitamin E. We used a mathematical approach in an effort to highlight some facts that might help address this question. Literature data on the relative composition of fatty acids (16:0, 16:1, 18:0, 18:1, 18:2, and 18:3) and the contents of tocopherols (α‐, β‐, δ‐, and γ‐tocopherol) in 101 oil samples, including 14 different botanical species, were analyzed by principal‐component analysis and linear regression. There was a negative correlation between α‐ and γ‐tocopherols (r=0.633, P<0.05). Results also showed a positive correlation between linoleic acid (18:2) and α‐tocopherol (r=0.549, P<0.05) and suggested a positive correlation between linolenic acid (18:3) and γ‐tocopherol.
High‐temperature stabilities of oils from soybeans that lack lipoxygenases
Authors: Shen N. , Fehr W. , White P. 
Published: May 2007

AbstractOils from normal or low‐linolenic acid (18:3) soybeans that lack lipoxygenase (LOX) 2 or LOX 2 plus LOX 3 activities were evaluated for their stability during frying and for oxidative stability in bread cubes stored after frying. Soybean oils were extracted by a pilot‐plant system and were refined, bleached, and deodorized in the laboratory. Citric acid was added to oils during the cool‐down stage of deodorization. Two replications, separated at the point of conditioning, were evaluated for each genotype. Each sample (250 g) was heated to 180±5°C in a minifryer. Bread cubes were fried at the beginning of heating and after 20 h of heating. Heating of the oils was continued for 10 h each day for three consecutive days. Soybean oils with low 18:3 contents were significantly (P ≤ 0.05) more stable, as measured by conjugated dienoic acids and polymer values, than were oils with normal 18:3 contents. Low‐LOX 2 or low‐LOX 2 + 3 activity had no effect on peroxide values of soybean oils extracted from bread cubes. Sensory evaluation did not differentiate between oils that contained low or high 18:3 amounts or among oils from beans that lacked different LOX enzymes.
Gas chromatographic study on high‐temperature thermal degradation products of methyl linoleate hydroperoxides
Authors: Toschi Tullia Gallina , Costa Arianna , Lercker Giovanni 
Published: May 2007

AbstractChromatographic techniques were used to separate secondary products generated by thermal degradation of methyl linoleate hydroperoxides (MLHP). The MLHP were obtained by oxidation, selected, and concentrated by solid‐phase extraction (SPE) and thin‐layer chromatography (TLC). The purified MLHP were then thermo‐degraded in the gas‐chromatographic glass liner and analyzed on‐line by gas chromatography‐mass spectrometry (GC‐MS). The MLHP were also thermodegraded and collected in a short silicic acid‐packed column, eluted, separated by TLC, and then analyzed by GC. By considering the elution in TLC, the GC retention times and the GC‐MS analyses, it was possible to characterize the mono‐ and the dioxygenated secondary products, particularly those having a boiling point higher than methyl linoleate. The peaks that corresponded to the mono‐oxygenated products (epoxy, hydroxy, and keto) were identified, and, on the basis of their MS spectra, molecular structures were proposed. A specific elution order was suggested for keto derivatives: 9‐keto,Δ10,12‐ and 13‐keto,Δ9,11‐octadecadienoate. The hydroxy derivatives, which show the typical fragmentations of 9‐hydroxy,Δ10,12‐ and 13‐hydroxy,Δ9,11‐octadecadienoate, were also identified. On the other hand, identification of the di‐oxygenated compounds was more difficult, and, therefore, it was not possible to indicate each positional isomer; however, their elution order could be epoxy‐hydroxy and epoxy‐keto derivatives.
Kinetics of epoxidation of alkyl esters of undecylenic acid: Comparison of traditional routes vs. ishii‐venturello chemistry
Authors: Yadav G. D. , Satoskar D. V. 
Published: May 2007

AbstractEpoxidation of undecylenic acid and its methyl and ethyl esters with aqueous H2O2 was carried out by using different traditional routes, ion exchange resin, and the newly developed synergistic usage of heteropoly acids and phase transfer catalysis in a biphasic system. The so‐called Ishii‐Venturello chemistry was employed to develop a kinetic model. Interesting selectivities are obtained.
Castor oil dehydration kinetics
Authors: Guner F. Seniha 
Published: May 2007

AbstractThe dehydration reaction kinetics of castor oil was investigated with sodium bisulfate‐sodium bisulfite mixture (SB‐SB) or p‐toluenesulfonic acid as catalyst. Reactions were carried out at 210, 220, and 230°C, and a kinetic model was determined for each case. The reactions with SB‐SB catalyst at 210 and 220°C and with p‐toluenesulfonic acid at 210°C followed second‐order kinetics. A first‐order rate equation showed the best fit to the experimental data for the reaction with SB‐SB at 230°C. p‐Toluenesulfonic acid‐catalyzed reactions at 220 and 230°C were also first‐order reactions. Additionally, some mathematical equations were derived between iodine value, refractive index, viscosity, and reaction time.
Fractionation of squalene from amaranth seed oil
Authors: Sun H. , Wiesenborn D. , Tostenson K. , Gillespie J. , Rayas‐Duarte P. 
Published: May 2007

AbstractAmaranth seed oil was fractionated in a bench‐scale short‐path distillation unit to obtain fractions rich in squalene. Fractionations were conducted with degummed amaranth oil, alkali‐refined amaranth oil, and simulated amaranth oil. Squalene concentration was increased about sevenfold with a squalene recovery of 76.0% in the distillate when degummed amaranth oil was fractionated at 180°C and 3 mtorr vacuum. Free fatty acids codistilled with squalene, lowering the squalene content of the distillate, and resulted in a semisolid distillate at room temperature. Alkali‐refining was subsequently used to reduce the free fatty acid content before fractionation. A simulated oil (7% squalene/93% soybean oil) and alkali‐refined amaranth oil were fractionated at three temperatures (160, 170, and 180°C) and five vacuum settings (10, 100, 200, 400, and 600 mtorr). The highest squalene recoveries from simulated oil and alkali‐refined amaranth oil were 73.4 and 67.8%, respectively, both at 180°C and 100 mtorr, which translates to 12.1‐and 9.2‐fold increases in squalene concentration, respectively. The squalene recovery of the alkali‐refined amaranth oil at 180°C was not significantly different at 10 mtorr vs. 100 mtorr. The results of this study can be used as a component to assess the economic feasibility of fractionating amaranth seed for starch, oil, meal, and squalene.
Synthesis of structured triglycerides from peanut oil with immobilized lipase
Authors: Soumanou Mohamed M. , Bornscheuer Uwe T. , Menge Ulrich , Schmid Rolf D. 
Published: May 2007

AbstractStructured triglycerides (ST) that contain medium‐ and long‐chain fatty acids were synthesized by lipase‐catalyzed interesterification between tricaprylin and peanut oil. To select appropriate enzymes, we investigated nine commercial lipase preparations for their ability to hydrolyze pure triglycerides as well as natural oils. Three microbial lipases from Rhizomucor miehei (RML), Candida sp. (CSL), and Chromobacterium viscosum (CVL) gave good results, and immobilized preparations were used in the interesterification. RML gave the highest yields of ST (73%, 40°C), although its hydrolytic activity toward triolein was low. As the temperature was raised to 50°C, the yield of ST increased to 79%. After 120 h reaction time, remaining activities were high for CSL (71%), moderate for CVL (48%), and low for RML (20%).
Stereoselective acylation of Dl‐menthol in organic solvents by an immobilized lipase from Pseudomonas cepacia with vinyl propionate
Authors: Wu Wen‐Hsin , Akoh Casimir C. , Phillips Robert S. 
Published: May 2007

AbstractAn effective lipase‐catalyzed stereoselective transesterification of (±)‐menthol in organic solvent with vinyl propionate as acylating agent is described. Immobilization by adsorption and the presence of molecular sieves improved the formation of (±)‐menthyl propionate by lipase (PS‐30) from Pseudomonas cepacia. The reaction time course, mole ratio of substrates, temperature, amount of enzyme, as well as the effect of various organic solvents, were examined for their influence on the enzymatic stereoselective formation of (−)‐menthyl propionate. Among the parameters studied, the stereospecificity toward (−)‐menthol decreased significantly as temperature increased but the yields of both enantiomers increased. Organic solvents with log P (partition coefficient) values above 3.5 gave higher yield and stereoselectivity than solvents with lower log P values.