bluuebunny/crossref_metadata_2025_split huggingface dataset:
Gas‐Liquid chromatography of fatty derivatives. I. Separation of homologous series ofa‐olefins, n‐hydrocarbons, n‐nitriles, and n‐alcohols
Authors: Link W. E. , Hickman H. M. , Morrissette R. A. 
Published: January 2007

SummaryGas‐liquid chromatography has been shown to be applicable to the analysis of several fatty derivatives. The difficulties inherent in conventional separation schemes such as liquid‐liquid chromatography, fractional distillation, and crystallization can be overcome through the use of gas‐liquid chromatography. It becomes the preferred procedure for several reasons: a) fractions are more nearly pure, b) analysis time is a fraction of the time required for conventional separations, c) operational procedures are simple and highly reproducible, d) sample size requirements are low, e) the cost per unit analysis is low.These factors suggest that gas‐liquid chromatography is highly useful as an analytical tool in fat research. In many cases the determination of chainlength distribution has already become a routine function.There remain areas in which gas‐liquid chromatography has not been completely successful. Until very recently the separation of fatty methyl esters of similar chain length and varying degrees of unsaturation has been time‐consuming and tedious. Several new partitioning agents hold out great promise in the separation of the isomeric C18 fatty acids. More selective partitioning agents and refined techniques undoubtedly will equally improve the resolution of unsaturated alcohols and other unsaturated fatty derivatives.
Equilibrium distributions of key components of spearmint oil in sub/supercritical carbon dioxide
Authors: Platin Sevan , Özer Elif Ö. , Akman Ugur , Hortaçsu Öner 
Published: January 2007

AbstractEffects of temperature (at 35, 45 or 55°C) and pressure (10–110 atm) on the relative distribution coefficients of the twelve key components of spearmint oil (essential oil ofMentha cardiaca; Scotch spearmint) at equilibrium in dense CO2 were investigated under conditions ranging from subcritical to supercritical regions. Effects of vapor pressure, molecular weight and polarity of the key components on their equilibrium distributions in sub/supercritical CO2 are discussed. At 35°C, all key components of spearmint oil are equally soluble in dense CO2 within the 12–102 atm pressure region. At 45 and 55°C, the key components are equally soluble for pressures greater than about 60 atm. However, around either 45°C/27 atm or 55°C/35 atm conditions, the relative distribution coefficients of all monoterpene hydrocarbons and of isomenthone (an oxygenated monoterpene) exhibit maxima, which are due to significantly higher vapor pressures of these components and significantly lower solvating power of the dense‐gas solvent at these particular temperatures and pressures. Vapor‐pressure effects, coupled with the decrease in solvating power, dominate the effects of polarity and molecular mass of the key components. Deterpenation of spearmint oil with dense CO2 is possible around either 45°C/27 atm or 55°C/35 atm, where the monoterpene hydrocarbons tend to concentrate in the CO2‐rich phase.
Benefits and limitations of a novel chlorophyll adsorbent
Authors: Chapman D. M. 
Published: January 2007

AbstractSilica hydrogels acidified with strong mineral acids, such as sulfuric acid, are highly effective chlorophyll and phospholipid adsorbents relative to traditional acid‐activated bleaching earth (ABE), but they are not effective β‐carotene adsorbents. When an acidified silica is used as the only bleaching agent, sulfuric acid leaches into the oil, and after deodorization, Tintometer red and yellow (R/Y) numbers are higher than those for ABE‐bleached and deodorized oils. The fixed R/Y colors do not arise solely from the decomposition of β‐carotene during deodorization. Sequential treatments of canola oils with sulfuric acid/silica and ABE can be performed to overcome all of the drawbacks associated with sulfuric acid/silica treatment alone, such that finished oils can be produced by lower overall adsorbent dosages.
The formation of oxo‐ and hydroxy‐fatty acids in heated fats and oils
Authors: Schwartz Daniel P. , Rady Aly H. , Castañeda Soledad 
Published: January 2007

AbstractA fast‐food fat (mostly tallow), olive oil and safflower oil were heated in air for 4 d and periodically analyzed for oxofatty acids (OFA), monohydroxy‐fatty acids (HFA) and polyhydroxy‐fatty acids (PHFA). After transmethylation, the OFA were estimated as 2,4‐dinitrophenylhydrazones, and the HFA and PHFA were quantitated as pyruvic acid 2,6‐dinitrophenylhydrazone esters. At least half of the maximum concentration attained for OFA, HFA and PHFA was generated between 16–24 h of heating of each oil. Safflower oil contained greater concentrations of HFA and PHFA than either olive oil or the fast‐food fat. The fastfood fat sample contained a greater concentration of OFA than did the other oils. The sum of the concentrations of OFA, HFA and PHFA at the time of maximum formation in the oils was approximately 260 μmoles/g at 48–72 h for safflower, 200 μmoles/g at 48–72 h for olive and 170 μmoles/g at 72 h for the fast‐food fat.
Triacylglycerol consumption during spore germination of vesicular‐arbuscular mycorrhizal fungi
Authors: Gaspar M. L. , Pollero R. J. , Cabello M. N. 
Published: January 2007

AbstractLipids and fatty acids of spores of the vesicular‐arbuscular mycorrhizal fungusGlomus versiforme were identified and quantitatively determined at different times of germination. Triacylglycerols were, by far, the most abundant lipid (38% on a wet‐weight basis). Phosphatidylethanolamine, together with minor quantities of other phospholipids, was the main polar lipid. Palmitoleic, palmitic and oleic acids were quantitatively the most important fatty acids in total lipids, and even more so in the triacylglycerol fraction. Minor percentages of fatty acids, identified as ω3 and ω6 polyunsaturated, completed the fatty acid spectra. Germination ofG. versiforme spores evokes a continuous decrease of triacylglycerols and an increase of phospholipids. The balance of fatty acids during germination suggests either a degradation or a transference of fatty acids from triacylglycerols to phospholipids.
Selectivity control in substituted fatty amines synthesis from esters or nitriles in the presence of bifunctional catalysts
Authors: Barrault J. , Brunet S. , Suppo‐Essayem N. , Piccirilli A. , Guimon C. 
Published: January 2007

AbstractCopper chromite‐type catalysts, supported by alumina or graphite and promoted with barium, were used for the onestep synthesis of tertiary fatty amines [R2NCH3 or RN(CH3)2] from ester, acid or nitrile and ammonia, methanol and hydrogen. The surface composition of the catalysts, studied by X‐ray photoelectron spectroscopy and by adsorption experiments, showed that there was a correlation between selectivity and the presence of a well‐dispersed CuCrO2 phase, stabilized with barium. Moreover, the elements influencing the stability of the copper catalysts were also studied, and the promoter or/and the support increased the copper surface area and the stability of the catalyst in the presence of water or ammonia.
Technological and economical aspects of the metathesis of unsaturated esters
Authors: Sibeijn M. , Poels E. K. , Bliek A. , Moulijn J. A. 
Published: January 2007

AbstractThe metathesis of alkenes is a well‐established reaction that is applied in various commercial processes. The meta‐thesis of functionalized olefins has not yet been commercialized despite its considerable potential. The conversion of oleochemical feedstocks into specialty chemicals appears especially attractive. In this paper, a process scheme is proposed for the production of 1,18‐dimethyl octadecanedioate from pure methyl oleate by metathesis. The chemical and technological bottlenecks are explored, and a rough economic evaluation of this route is given. From these considerations, it is concluded that such a process for the metathesis of functionalized alkenes could be viable only if certain conditions are met. Rapid catalyst deactivation is identified as one of the main obstacles. Feedstock purity, efficient recycling of unreacted feed and multiple catalyst regeneration are crucial for economic feasibility. Rhenium‐based catalysts are to be preferred over molybdenum ones because their activation is easier and regenerability is superior. Finally, the direction for future technological and catalysis research is given based upon the results of this work.
Effects of the degree of unsaturation of coexisting triacylglycerols on cholesterol oxidation
Authors: Li Nan , Ohshima Toshiaki , Shozen Kei‐ichi , Ushio Hideki , Koizumi Chiaki 
Published: January 2007

AbstractIn order to evaluate the effects of the degree of unsaturation of triacylglycerols on cholesterol oxidation, mixtures of purified sardine oil triacylglycerols (iodine value, IV=182.6) and cholesterol; of partially hydrogenated sardine oil triacylglycerols (IV=174.5) and cholesterol; and of fully hydrogenated sardine oil triacylglycerols (IV=92.0) and cholesterol were incubated at 25°C in the dark. The oxidative stability of the samples decreased with increasing degree of unsaturation of the triacylglycerols in the sample mixtures; the induction period for peroxide values (PV) of the sardine oil triacylglycerols and cholesterol was shorter than that of the partially hydrogenated sardine oil triacylglycerols and cholesterol. Certain polyunsaturated fatty acids (PUFAs) in the constituent fatty acids of sardine oil triacylglycerols started to decrease after a shorter induction period compared with that of the partially hydrogenated triacylglycerols. The prominent cholesterol oxides accumulated in the samples were 7β‐hydroxycholesterol, 7‐ketocholesterol, β‐epoxide and cholestane triol. The tendency for accumulation of cholesterol oxides in the time course coincided with the changes in PV as well as the decrease in PUFAs. Cholesterol was oxidized in conjunction with autoxidation of coexisting fish oil triacylglycerols. Although lowering the degree of unsaturation of fish oil triacylglycerols was effective in prolonging the induction period of cholesterol oxidation, the rate of cholesterol oxidation in the cholesterol oxides' formation phase after the induction period was not affected by the difference in the proportion of highly unsaturated fatty acids in the natural and partially hydrogenated triacylglycerols of fish oils.
Pilot‐plant selective hydrogenation of soybean oil: Activation and evaluation of copper‐containing catalysts
Authors: Moulton K. J. , Moore D. J. , Beal R. E. 
Published: January 2007

AbstractIn pilot‐plant tests, the linolenate content of soybean oil was reduced to less than 1% without increasing the saturates, by hydrogenation to an IV of about 115 with an active copper‐chromite catalyst. The linolenate‐linoleate selectivity ratio (KLe/KLo) was from 9 to 12. Several commercial copper‐chromite catalysts were used in hydrogenation tests. The activities of four of five commercial catalysts tested were improved to various degrees by heating in air at 350 C (one was inactive both before and after heating). Examination by differential thermal analysis (DTA) of each catalyst, just as received and then after being heated at 350 C, demonstrated that heating greatly diminished or removed peak areas from the DTA curve. Studies made with one commerical copper‐chromium‐barium catalyst showed that heating the catalyst was also necessary to gain maximum linolenate‐linoleate selectivity in hydrogenating soybean oil.
Relationship of structure to properties of surfactants. 15 Isomeric sulfated polyoxyethylenated Guerbet alcohols
Authors: Murphy D. S. , Zhu Z. H. , Yuan X. Y. , Rosen M. J. 
Published: January 2007

AbstractThe properties at 25°C in aqueous 0.1M NaCl at the aqueous solution/air, aqueous solution/hexadecane, and aqueous solution/hydrophobic solid interfaces of two isomeric Guerbet alcohol‐derived surfactants C8H17CH(C6H13)CH2(OC2H4)5SO4Na, one in which the octyl and hexyl groups are both linear (L isomer), the other in which they are both highly branched (B isomer), have been investigated and compared in some cases with commercial sodium linear dodecylbenzene‐sulfonate (LAS). The cmc value increases, the pC20 value decreases, and the ΔGoad value becomes less negative in the order: L isomer—B isomer—LAS. The minimum area/molecule at the aqueous solution/air interface increases in the order: LAS≪L isomer<B isomer.The L isomer is slightly more hydrophobic than the B isomer, and both are considerably more surface‐active than LAS. The greater steric inhibition to micellization in the B isomer results in the lowest minimum surface tension. Both isomers have similar minimum interfacial tension values against hexadecane. Unusually small minimum area/molecule values for the two isomers at the aqueous solution/hydrophobic solid interface may indicate multilayer adsorption there. Both isomers are more efficient at reducing the contact angle than LAS. Mixtures of the B isomer with the corresponding unsulfated Guerbet alcohol show only weak interaction between the two. No synergism in surface (or interfacial) tension reduction efficiency or micelle formation exists at either the aqueous solution/air or aqueous solution interface but the mixture does show synergism in surface (or interfacial) tension reduction effectiveness, yielding a surface tension value of 28.2 dynes/cm, and an interfacial tension value of 0.1 dyne/cm against hexadecane. Draves wetting times increase in the order: B isomer<LAS<L isomer, and Ross‐Miles initial foam heights decrease in the order B isomer ≈LAS>L isomer.
Influence of interesterification on the oxidative stability of marine oil triacylglycerols
Authors: Kimoto Hiromi , Endo Yasushi , Fujimoto Kenshiro 
Published: January 2007

AbstractTo understand the relationship between triacylglycerol structure of marine oils and their oxidative stability, peroxide values and absorbed oxygen levels of whale, sardine, cod liver and skipjack oils, interesterified by lipase and NaOCH3, were compared with those of native oils during storage at 40°C. Triacylglycerol structures of marine oils were characterized by high‐performance liquid chromatography and differential scanning calorimetry analyses. Enzymatically interesterified fish oils were more stable than native oils because the level of highly unsaturated triacylglycerols was decreased. However, the oxidative stability of interesterified whale oil was more susceptible to oxidation than the native oil.
Enzymatic phosphatidylcholine hydrolysis in organic solvents: An examination of selected commercially available lipases
Authors: Haas M. J. , Scott K. , Jun W. , Janssen G. 
Published: January 2007

AbstractEight commercial lipase preparations were examined for the ability to hydrolyze phosphatidylcholine (PC) in hexane solutions. Only the enzymes fromHumicola lanuginosa, Rhizopus delemar andCandida rugosa displayed appreciable activity. Solvent polarity was the largest single factor affecting activity. TheH. lanuginosa sample was most active in polar solvents. TheR. delemar preparation was most active in polar (2‐hexamone) and nonpolar (decane) solvents and least active in solvents of intermediate polarity (hexane). The solvent dependence of the activity of theC. rugosa enzyme varied with the ratio of substrate to enzyme. Different degrees of activity were retained by the three enzymes after passive immobilization on Celite, controlled‐pore glass, polypropylene and Amberlite XAD‐7 resins. No single resin yielded the best retained activity for all three preparations. When examined in 2‐octanone, hexane and isooctane, the Celite‐immobilizedR. delemar andH. lanuginosa enzymes exhibited highest activity in 2‐octanone, while immobilizedC. rugosa was most active in isooctane. The water content at which maximum activity was observed was relatively independent of solvent polarity and the amount of catalyst but was proportional to the amount of PC in the reaction. The retention of activity by immobilizedRhizomucor miehei lipase (Lipozyme) during multiple hydrolytic cycles required a reduction in the water content of the system below that yielding optimal activity in a single cycle.
Kinetics of catalytic transfer hydrogenation of soybean oil
Authors: Smidovnik A. , Kobe J. , Leskovsek S. , Koloini T. 
Published: January 2007

AbstractThe catalytic transfer hydrogenation of soybean oil was studied by using various concentrations of sodium formate solutions, an emulsifier and paladium on a carbon catalyst. Sodium formate concentration and addition of the emuldifier significantly affect the reaction rate because of their influence on the liquid/liquid interface. Under conditions in which diffusion effects are eliminated, all reactions carried out in diluted sodium formate solution obey first‐order kinetics with respect to fatty acids. This allows control over the hydrogenation process of soybean oil, needed to obtain partially hydrogenated oil containing about 1% linolenic acid and a relatively high level of linoleic acid with no increase in the stearic acid concentration.
Oil and minor components of sesame (Sesamum indicum L.) strains
Authors: Tashiro T. , Fukuda Y. , Osawa T. , Namiki M. 
Published: January 2007

Oil and mior components of sesamin and sesamolin were studied in 42 strains ofSesamum indicum L. The oil contents of the seed ranged from 43.4 to 58.8% and varied inversely with the percentage of hull (r=−0.804, significant at the 1% level). The hull percentage was used as a criterion to predict oil content. The percentage of sesamin in the oil ranged from 0.07 to 0.61% and that of sesamolin from 0.02 to 0.48%. There was a significant positive correlation between the oil content of the seed and the sesamin content of the oil (r=0.608, significant at the 1% level); no correlation was found between the oil and sesamolin contents.The average oil content found for the white‐seeded strains was 55.0% and for the black‐seeded strains 47.8%, the difference of 7.2% being significant at the 1% level. The white‐ and black‐seed strains also differed significantly in sesamin content, but not in sesamolin content.
Oxidative stability of soybean oil at different stages of refining
Authors: Kwon T. W. , Snyder H. E. , Brown H. G. 
Published: January 2007

AbstractOxidative stabilities of soybean oil samples at 7 different stages of commercial refinement were measured by weight increases. Also, a method was developed for isolating essentially pure soybean triglyceride, and its oxidative stability was measured. Crude oil was most stable and the highly purified soybean triglyceride was least stable, with other samples being intermediate in stability. Adding phospholipids and tocopherols to the highly purified soybean triglyceride gave its oxidative stability, and in combination they were synergistic in delaying oxidation. The weight increase method demonstrated that surface exposure is an important variable in rates of autoxidation.
Sensory characteristics and oxidative stability of soybean oil and flour extracted with aqueous isopropyl alcohol
Authors: Warner K. , Baker E. C. 
Published: January 2007

AbstractSoybean flakes extracted with hexane or aqueous isopropyl alcohol (85%, 87.7% and 90.5% IPA by weight) were processed to toasted flours and the miscellas to refined soybean oils. These products were evaluated for sensory characteristics and oxidative stability. Sensory analyses of initial oils and flours indicated good quality products. Initial flavor scores of IPA‐extracted oils and flours were not significantly different from those of hexane‐extracted oil and flour. Flour samples aged at 49 C for 1 mo and 37 C for 3 mo were rated slightly lower in flavor score than the initial flours. Flavor scores of oils decreased after aging but remained acceptable. Oils extracted with aqueous IPA concentrations of 85% and 90.5% received significantly lower scores than oils extracted with hexane or 87.7% IPA after 8 hr of fluorescent light exposure. Oxidative stability measured by the induction of weight increases of the oils during aging was similar. Residual solvent flavors were slightly detectable in unaged IPA flours and in those aged 3 mo at 37 C.
Use of a gas chromatographic reactor to study lipid photooxidation
Authors: Faria J. A. F. , Mukai M. K. 
Published: January 2007

AbstractA gas chromatographic reactor can be used to investigate the prooxidant activities of different light sources on polyunsaturated lipids, including linoleic acid and safflower oil. The rate of oxidation was followed from the early stages of oxygen uptake, using a thermal conductivity detector (TCD). The experiments were made at low O2 concentrations and at a broad range of temperatures. To monitor the effect of light on the oxidation of linoleic acid, chlorophyll and methylene blue were used as sensitizers, and β‐carotene was used as a reported inhibitor of oxidation. The simultaneous measurements of oxygen uptake and volatiles formation were also monitored using a TCD and flame ionization detector (FID). The method is presently being developed as a technique to predict the stability of fatty foods packaged in transparent or translucent materials.
Solid phases of trimargarin: A comparison to tristearin
Authors: Simpson T. D. 
Published: January 2007

AbstractData from Raman spectroscopy, X‐ray diffraction, infrared spectroscopy and differential scanning calorimetry confirm the existence of four solid state phases for trimargarin. Results of the trimargarin investigation are compared to previous results of tristearin and examined in the light of odd vs even chain‐length triglycerides. The conclusion reached is that polymorphic properties of triglycerides result from a balance of three dominant interactions: end‐group planar interactions, lateral hydrocarbon chain interactions and glycerol units intermolecular interactions. This contrasts to a general belief that the end‐group planar interactions dictate physical behavior of lipids.
Polycarboxylic acids containing acetal functions: calcium sequestering compounds based on oxidized carbohydrates
Authors: Nieuwenhuizen M. S. , Kieboom A. P. G. , van Bekkum H. 
Published: January 2007

AbstractA number of polycarboxylic acids containing acetal functions have been prepared by a two‐step oxidation of carbohydrates. Their calcium sequestering behavior is compared with that of a series of model polycarboxylic acids. It is found that calcium sequestration by oxidized carbohydrates is less than that by corresponding ether polycarboxylates, since (a) acetal oxygens have a lower coordinating power than ether oxygens, and (b) there is extra steric repulsion upon calcium complexation by both the additional CH2 OH groups and the unfavorable natural configuration of the oxidized carbohydrates investigated. Some of the oxidized carbohydrates show greater calcium sequestering capacities than corresponds to the stability constant. This is probably caused by crystal growth inhibition or precipitation‐inhibition phenomena. Two model compounds illustrate that the acetal moiety is sufficiently stable under washing conditions, whilst it hydrolyses under acidic waste water conditions into small (hydr)oxycarboxylates.