bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of processing on oxidative stability of sesame oil extracted from intact and dehulled seeds
Authors: Abou‐Gharbia H. A. , Shahidi F. , Adel A. , Shehata Y. , Youssef M. M. 
Published: May 2007

AbstractOxidative stability of oils extracted from intact and dehulled sesame seeds was determined by monitoring changes in fatty acid composition, iodine value (IV), peroxide value (PV), conjugated diene (CD), para‐anisidine value (p‐AV), and 2‐thiobarbituric acid (TBA) value and by nuclear magnetic resonance spectroscopy after storage under Schaal oven conditions at 65°C for up to 35 d. The oils from coated seeds were more stable, as reflected in PV, CD, p‐AV and TBA values, than those extracted from dehulled seeds after roasting at 200°C, steaming at 100°C, roasting at 200°C plus steaming, or microwaving at 2450 MHz, except for TBA values of oil from microwaved seeds. After 35 d of storage at 65°C, the CD, p‐AV, and TBA values of extracted oil from dehulled microwaved seeds were 17.72, 10.20, and 1.22, respectively, while those of their coated counterparts were significantly (P<0.05) different at 14.20, 16.47, and 1.26, respectively. Few significant changes were evident in the fatty acid composition of oil obtained from either coated and dehulled seeds subjected to different treatments. Nuclear magnetic resonance analyses found that Rao (aliphatic to olefinic protons) and Rad (aliphatic to diallylmethylene protons) ratios increased steadily over the entire storage period, which indicated progressive oxidation of unsaturated fatty acids.
Preparation and characterization of methyl 11‐amino‐(N‐p‐toluenesulfonyl)‐9‐E‐octadecenoate and methyl 8‐amino‐(N‐p‐toluenesulfonyl)‐9‐E‐octadecenoate
Authors: Herron Barry F. , Bagby Marvin O. , Isbell Terry A. , Byrdwell Wm. Craig , Plattner Ron , Weisleder David 
Published: May 2007

AbstractAllylic amination of methyl oleate with bis(N‐p‐toluenesulfonyl) sulfodiimide results in a mixture of methyl 11‐amino‐(N‐p‐toluenesulfonyl)‐9‐E‐octadecenoate and methyl 8‐amino‐(N‐p‐toluenesulfonyl)‐9‐E‐octadecenoate in 58% yield. These novel products were isolated and characterized by nuclear magnetic resonance, infrared spectroscopy, mass spectrometry, and melting point. The reaction was analyzed by highperformance liquid chromatography and thin‐layer chromatography.
Synthesis of alkyloxy (di)alkylamino propanols, hydroxy alkyloxy (di)alkylamino propanols, and the dimer compounds for use as fuel additives
Authors: de Caro Pascale Satgé , Mouloungui Zéphirin , Gaset Antoine 
Published: May 2007

AbstractAlkyl glycidyl ethers and bis glycidyl ethers, synthesized in a heterogeneous weakly hydrous medium, were condensed with primary or secondary amines to obtain 3‐alkyloxy propanolamines or bis alkyloxy propanolamines in a regioselective manner. The compounds were characterized by conventional spectroscopic methods, and complete nuclear magnetic resonance data are given. Their high‐temperature stability, their good emulsifying power, their oxidation, and corrosion inhibition make these compounds suitable for solubilizing ethanol‐diesel fuel blends.
Synthesis of derivatives of alkylamino alkyloxy propanol structures by N‐alkylation, acylation, and nitration. Application as fuel additives
Authors: de Caro Pascale Satgé , Mouloungui Zéphirin , Gaset Antoine 
Published: May 2007

AbstractPolyfunctional compounds were prepared by alkylation, acylation, and nitration of hydroxyl and amine functions of the following alkanolamine ether structures: (di)alkylamino alkyloxy propanol, hydroxy alkyloxy (di)alkylamino propanol, and their dimer compounds. The resulting compounds were characterized by conventional spectroscopic methods, and complete nuclear magnetic resonance data are given. These reactions extented the application of these propanic compounds to use as multipurpose fuel additives. In particular, they enhance phase stability and improve the cetane number in ethanol‐diesel fuel blends.
Lipase PS‐catalyzed transesterification of citronellyl butyrate and geranyl caproate: Effect of reaction parameters
Authors: Yee Lisa N. , Akoh Casimir C. , Phillips Robert S. 
Published: May 2007

AbstractPseudomonas sp. lipase PS was immobilized by adsorption and tested for its ability to catalyze the synthesis of citronellyl butyrate and geranyl caproate by transesterification in n‐hexane. The reaction parameters investigated were: enzyme load, effect of substrate concentration, added water, temperature, time course, organic solvent, pH memory, and enzyme reuse. Yields as high as 96 and 99% were obtained for citronellyl butyrate and geranyl caproate, respectively, with 300 units (approx. 15% w/w of reactants) of lipase PS. Increasing amounts of terpene alcohol inhibited lipase activity, while excess acyl donor (triacylglycerol) concentration enhanced ester production. Optimal yields were obtained at temperatures from 30–50°C after 24‐h incubation time. Yields of 90 and 99% were obtained for citronellyl and geranyl esters, respectively, with 2% added water. Solvents with log P values ≥ 2.5 showed the highest conversion yields. pH 7 and 6–8 seemed to be ideal for citronellyl butyrate and geraniol caproate, respectively. The lipase remained active after reusing 12 times.
Enzymatic modification of triolein: Incorporation of caproic and butyric acids to produce reduced‐calorie structured lipids
Authors: Fomuso Lydia B. , Akoh Casimir C. 
Published: May 2007

AbstractLipase‐catalyzed acidolysis of triolein with caproic and butyric acids was performed to produce reduced‐calorie structured lipids (SL). The SL were obtained by incubating a 1:4:4 mole ratio of triolein, caproic acid, and butyric acid, respectively, with 10% of lipase (w/w of total substrates) in 1.5 mL hexane at 55°C for 24 h. Of nine commercially avaialble lipases screened, IM60, which contains the lipase from Rhizomucor miehei, was the most effective and produced 13 mol% unreacted triolein, 49% disubstituted, and 38% monosubstituted triacylglycerols that contained short‐chain fatty acids. The products were analyzed by reverse‐phase high performance liquid chromatography with an evaporative light‐scattering detector. Reaction parameters studied included time course, temperature, enzyme load, and substrate mole ratio. The yields obtained demonstrate that a structured lipid with long‐chain and short‐chain fatty acids can be synthesized by using IM60 lipase in organic medium.
Nondestructive single‐seed oil determination of meadowfoam by near‐infrared transmission spectroscopy
Authors: Patrick Brett E. , Jolliff Gary D. 
Published: May 2007

AbstractNear‐infrared transmission spectroscopy (NITS) was explored for single‐seed oil determination of meadowfoam. Two calibration sets were determined by principle component analysis of recorded spectra. Nuclear magnetic resonance (NMR) spectroscopy was used for oil content determination. The calibrations had standard errors of cross‐validation of 3.6 and 4.4%, respectively, with an oil content ranging from 0.8 to 45.7%. This error is similar to that reported for NITS of single maize kernels, relative to the respective oil content ranges. Although not as accurate as NMR spectroscopy, NITS does provide a fast, efficient, and nondestructive method of predicting oil content of individual meadowfoam seeds.
Analysis of seed oil from ricinus communis and dimorphoteca pluvialis by gas and supercritical fluid chromatography
Authors: Borch‐Jensen Christina , Jensen Benny , Mathiasen Kim , Mollerup Jørgen 
Published: May 2007

AbstractThe seed oils from Dimorphoteca pluvialis and Ricinus communis contain hydroxy fatty acids. Dimorphoteca pluvialis contains Δ‐9‐hydroxy‐10t, 12t‐octadecadienoic acid (dimorphecolic acid) and R. communis contains Δ‐12‐hydroxy‐9c‐octadecenoic acid (ricinoleic acid). The oils were derivatized and analyzed to determine the content of hydroxy fatty acids. The trimethylsilyl fatty acid methyl ester (TMS‐FAME) derivatives were analyzed by capillary gas chromatography (GC), and the free fatty acid (FFA) derivatives and the oils were analyzed by capillary supercritical fluid chromatography (SFC). Further, mass spectroscopy of the TMS‐FAME derivatives was performed to check the purity of the derivatives. The results from the GC analyses of TMS‐FAME corresponded to the results found by SFC analysis of the FFA. The content of ricinoleic acid in the glycerolipids of R. communis was 87.7 wt%, and the content of dimorphecolic acid in D. pluvialis was 54.0 wt%. The methods were evaluated with respect to the cost, ease, and time needed for sample preparation and analysis.
A method for determining kernel moisture content and aflatoxin concentrations in peanuts
Authors: Dorner Joe W. , Cole Richard J. 
Published: May 2007

AbstractA method was developed to determine kernel moisture content (KMC) and aflatoxin concentration in discrete peanut samples. Shelled peanuts were weighed to the nearest 0.01 g, and a water slurry was made by blending the peanuts for 2 min with 2.2 ml of water per g of peanuts. The slurry (10 g) was withdrawn and dried at 130°C for 3 h to determine KMC. Methanol was added to the remaining slurry and blended for an additional 1 min, and aflatoxins were quantitated with high‐performance liquid chromatography. Comparison of the slurry method with an official peanut moisture method showed good agreement between the two over a range of moisture levels. Recovery of aflatoxin B1 from spiked samples averaged 97% with an average coefficient of variation of 3.6%. The method enables determination of both KMC and aflatoxin content in peanut samples without degradation of aflatoxin that would occur when using the official moisture method.
Diffuse reflectance fourier transform infrared spectroscopy of triacylglycerol and oleic acid adsorption on synthetic magnesium silicate
Authors: Yates R. A. , Caldwell J. D. , Perkins E. G. 
Published: May 2007

AbstractDiffuse reflectance fourier transform infrared (FTIR) was used to observe adsorption complexes of triacylglycerol and oleic acid on silica gel and synthetic magnesium silicate. The spectra provide evidence of the nature of the surface interaction. Triacylglycerol was shown to be physically adsorbed to both adsorbents. Oleic acid was physically adsorbed to the silica gel, but both physically and chemically adsorbed to the magnesium silicate. The FTIR spectrum of magnesium silicate that was used to treat a degraded frying oil was similar to that of oleic acid adsorbed on magnesium silicate.
Identification and function of antioxidants from oat groats and hulls
Authors: Xing Youmin , White Pamela J. 
Published: May 2007

AbstractAntioxidant components of methanolic extracts of groats and hulls from Ogle oats were identified and quantified by using gas chromatography‐mass spectrometry (GC‐MS) and gas chromatography after N,O‐bis(trimethylsilyl)acetamide derivatization. Ferulic, p‐coumaric, vanillic, p‐hydroxybenzoic, 4‐hydroxyphenylacetic acids and vanillin and catechol were quantified in groat and hull extracts. Additionally, caffeic acid in groat extracts, and o‐coumaric, sinapic and slaicylic acids in hull extracts were quantified. Extracts from groats and hulls at levels of 0.05, 0.1, 0.2, and 0.3% w/w, based on total phenolic content, were added to soybean oil, and their antioxidant effectiveness was compared with that of 0.02% w/w tertiary butylhydroquinone (TBHQ) and a control (no additives) at 60°C in the dark by measuring peroxide values. Antioxidant activities of both extract sources increased with increased concentration. During 20 d of storage, the groat extract (0.3%) was not significantly different from TBHQ after day 16, and hull extracts (0.2 and 0.3%) were not significantly different from TBHQ on day 20. Oils containing pure phenolics at the same concentrations measured in the groat and hull extracts oxidized more quickly than did oils containing the extracts.
Determination of environmentally relevant physical‐chemical properties of some fatty acid esters
Authors: Krop Hildo B. , Velzen Martin J. M. v. , Parsons John R. , Govers Harrie A. J. 
Published: May 2007

AbstractFat models frequently use input parameters that are defined at environmental conditions. In a recently developed gas‐liquid chromatography method (GC‐VAP), vapor pressures, heats of vaporization, and heat capacity differences (gas‐liquid) of fatty acid esters are determined over a large temperature range that includes environmental temperatures. This method also allows an accurate determination of the normal boiling point temperature of a substance. Literature values of vapor pressure, boiling point temperature, and heat of vaporization at 298.15 K for the chosen esters are all in excellent agreement with those determined with the developed method. Correlations between carbon number and heat of vaporization are high.
Stability of furanoid fatty acids in soybean oil
Authors: Guth Helmut , Grosch Werner 
Published: May 2007

AbstractAnalysis of the positional distribution of the furanoid fatty acids, 10,13‐epoxy‐11,12‐dimethyloctadeca‐10, 12‐dienoic acid (F20) and 12,15‐epoxy‐13,14‐dimethyleicosa‐12,14‐dienoic acid (F22), in soybean oil (SBO) indicated that they were preferentially esterified with the primary‐OH groups of glycerol molecules. Hydrogenation of SBO reduced the concentrations of F20 and F22 somewhat. During exposure of SBO to daylight, F20 and F22 were completely degraded within two days, whereas linoleic acid and linolenic acid were not affected. β‐Carotene inhibited both the degradation of the furanoid fatty acids and their oxidation to the odorant 3‐methyl‐nonane‐2,4‐dione (MND), which contributes strongly to the light‐induced off‐flavor of SBO. A model experiment indicated that two days of light exposure of SBO, followed by filtration through silica gel and further refining, prevented the formation of MND during subsequent storage of the oil.
Comparison of rancimat evaluation modes to assess oxidative stability of fish oils
Authors: Méndez Eduardo , Sanhueza Julio , Speisky Hernán , Valenzuela Alfonso 
Published: May 2007

AbstractTwo Rancimat evaluation modes, the induction period (IP), and the time needed to achieve a selected difference in conductivity (tΔK) were compared for assessing relative stability of anchovy, sardine, and hake liver oils. Mean coefficients of variation were 2.5 and 2.4% for IP and tΔK values, respectively, for oils oxidized in the range 55–90°C. Natural logarithms of IP and tΔK values varied linearly with temperature (P<0.001). A linear relationship (r=0.999) was established between the IP and tΔK values (P<0.001). Relative oxidative stability of fish oils was determined with the same degree of confidence by either IP or tΔK values.
Isothermal crystallization of tripalmitin in sesame oil
Authors: Dibildox‐Alvarado Elena , Toro‐Vazquez Jorge F. 
Published: May 2007

AbstractCrystallization of tripalmitin (TP) in sesame oil was investigated under isothermal conditions at a cooling rate similar to the one achieved in industrial crystallizers (1 K/min). The results obtained indicated that, at TP concentrations <0.98%, triacylglycerides of sesame oil developed mixed crystals with TP. However, at concentrations within the interval of 0.98 to 3.44%, tripalmitin crystallized independently from sesame oil. Within this concentration interval, discontinuities were observed in the behavior of the induction time of TP crystallization (Ti) in sesame oil as evidenced by differential scanning calorimetry, polarized microscopy studies, and determination of the Avrami index (n). In general, the discontinuities in Ti were associated with different polymorph states developed by TP in sesame oil as a function of its concentration and crystallization temperature. Thus, TP crystals obtained at temperatures above 296 K with 1.80 and 2.62% TP solutions had n values close to 3 and developed lamellar‐shaped crystals that are characteristic of β tripalmitin. In contrast, the crystals obtained at temperatures of 296 K and below with 1.80% and 2.62% TP solutions provided n values close to 3. Axialite‐shaped β′ TP crystals were obtained under these conditions. For the 0.98% TP solution, simultaneous production of α and β′ crystals occurred below 291 K. However, at temperatures above 291 K, a crystallization process with n=3 was obtained, and it developed a different polymorph state, i.e., β, with lamellar‐shaped TP crystals.
Synthesis of phosphatidylglycerol from soybean lecithin with immobilized phospholipase D
Authors: Wang XingGuo , Qiu AiYong , Tao WenYi , Shen PeiYing 
Published: May 2007

AbstractPhosphatidylglycerol (PG) was synthesized from soybean lecithin with the help of phospholipase D (PLD) that was immobilized with calcium alginate gel‐enveloped polyethyleneimine‐glutarald ehyde. The immobilization conditions were optimized with response surface analysis: Ca‐alginate 1.39%, polyethyleneimine 7.78%, glutaraldehyde 1.22%. The conversion of phosphatidylglycerol was 87%. The properties of the immobilized PLD were: optimal temperature 25–30°C, optimal pH 8.2, ratio of ether phase and water phase 1.5–2.5:1 (vol/vol), repeated 15 batches operating with stabilizing conversion percentage of phosphatidylglycerol.
Alteration of steryl ester content and positional distribution of fatty acids in triacylglycerols by chemical and enzymatic interesterification of plant oils
Authors: Ferrari R. Ap. , Esteves W. , Mukherjee K. D. 
Published: May 2007

AbstractSteryl ester content of refined and interesterified corn, soybean, and rapeseed oils has been measured via clean‐up on a short silica gel column, followed by high performance liquid chromatography with evaporative light‐scattering mass detector. Chemical interesterification, catalyzed by sodium methoxide, led to random positional distribution of fatty acids in triacylglycerols and some increase in the steryl ester content of all three oils. Enzymatic interesterification, catalyzed by the immobilized lipase from Rhizomucor miehei (Lipozyme), resulted in a distinct reduction in steryl ester content, but essentially no alteration in positional distribution of fatty acids in triacylglycerols occurred. Formation of steryl esters during chemical and enzymatic interesterification was also examined by radioactive tracer technique with [4‐14C]β‐sitosterol added as marker to refined rapeseed oil and measurement of the radioactive steryl esters formed. Chemical interesterification of rapeseed oil resulted in moderate formation (10% of total radioactivity) of radioactive β‐sitosteryl esters. Enzymatic interesterification of the oil, catalyzed by Lipozyme, led to little formation of radioactive β‐sitosteryl esters, whereas with the lipase from Candida cylindracea high proportions (>90% of total radioactivity) of 14C‐labeled β‐sitosteryl esters were formed.
Lipase‐catalyzed glycerolysis of soybean oil in supercritical carbon dioxide
Authors: Jackson Michael A. , King Jerry W. 
Published: May 2007

AbstractThe transesterification of soybean oil with glycerol, 1,2‐propanediol, and methanol by an immobilized lipase in flowing supercritical carbon dioxide for the synthesis of monoglycerides is described. A lipase from Candida antarctica was used to catalyze the reaction of soybean oil with glycerol, 1,2‐propanediol, ethylene glycol, and methanol. Reactions were performed in supercritical carbon dioxide at a density of 0.72 g/L and at a flow rate of 6 µL/min (expanded gas). The substrates were added at flows ranging from 2.5 to 100 µL/min. Monoglycerides were obtained at up to 87 wt%, and fatty acid methyl esters at nearly 100 wt%. The reactivity of the alcohols paralleled the solubility of the substrate in liquid carbon dioxide. Glycerol has the slowest reaction rate, only 2% of that of methanol.
Immobilization of lipases on porous polypropylene: Reduction in esterification efficiency at low loading
Authors: Bosley John A. , Peilow Alan D. 
Published: May 2007

AbstractRhizomucor miehei, Humicola sp., Rhizopus niveus, and Candida antarctica B lipases were immobilized by physical adsorption onto a macroporous polypropylene support. In an esterification reaction, the enzyme efficiency, and therefore cost‐effectiveness, is greatly affected by enzyme loading, with an apparent suppression of efficiency at low lipase loadings for both R. miehei and Humicola sp. lipases. This results in the appearance of a pronounced maximum in the efficiency‐loading relationship at approximately 100,000 lipase units (LU)/g for R. miehei lipase (10% of its saturation loading) and at approximately 200,000 LU/g for Humicola sp. lipase (50% of its saturation loading). The other lipases studied do not show similar trends. At low loadings, only a small portion of the surface area is occupied and gives the lipase the opportunity to spread; it is hypothesized that the reduction in efficiency at low loadings is due to a distortion of the active molecular conformation caused by the lipase maximizing its contact with the support as a result of its high affinityfor the support surface. The relationship between efficiency and loading was different for each of the lipases studied, which may reflect both differences in the strength of the affinity of the lipase for the support and in the ease at which the molecular conformation of the lipase can be distorted.
Alcoholysis of palm oil mid‐fraction by lipase from Rhizopus rhizopodiformis
Authors: Basri M. , Heng A. C. , Razak C. N. A. , Wan Yunus W. M. Z. , Ahmad M. , Rahman R. N. A. , Ampon K. , Salleh A. B. 
Published: May 2007

AbstractA mycelial lipase from Rhizopus rhizopodiformis was prepared in fragment form. The lipase was examined to catalyze the alcoholysis of palm oil mid‐fraction (PMF) in organic solvents. High percentage conversions of PMF to alkyl esters were achieved when methanol or propanol was used as acyl acceptor. Of the two most prevalent fatty acids in PMF, palmitic acid seemed to be preferred over oleic acid in the formation of methyl and propyl esters. The optimal ratio of oil to methanol in the alcoholysis reaction is 1 to 2 moles. The lipase exhibited high alcoholysis activities in nonpolar solvents (log P>2), such as hexane, benzene, toluene, and heptane. The enzyme showed exceptionally high thermostability.
Microwave roasting and phospholipids in soybeans (Glycine max. L.) at different moisture contents
Authors: Yoshida Hiromi , Takagi Sachiko , Kajimoto Goro , Yamaguchi Maki 
Published: May 2007

AbstractThe effects of microwave roasting on phospholipids in soybeans were investigated in relation to moisture. Whole soybeans at different moistures (9.6, 38.2, and 51.9%) were roasted by exposure to microwaves at a frequency of 2,450 MHz. During microwave treatments, the lower the moisture content, the higher was the internal temperature in soybeans at the end of microwave roasting. Total lipids were extracted from the beans after microwave treatment, and the phospholipids were separated with thin‐layer chromatography. Phosphatidylcholine was the principal phospholipid in the extracted lipids from all unroasted and roasted bean samples. After microwave roasting, phospholipids containing an amino group, especially phosphatidylethanolamine, decreased substantially (P<0.05) in lower‐moisture soybeans. However, increasing the moisture content depressed a rise in the internal temperature of soybeans and prevented a reduction in phospholipids and/or polyunsaturated fatty acids in the phospholipids. Based on the changes in the composition and fatty acid distribution of phospholipids in soybeans during microwave roasting, it is necessary to consider the moisture content in soybeans when roasting in a microwave oven.