bluuebunny/crossref_metadata_2025_split huggingface dataset:
Selective binding of docosahexaenoic acid ethyl ester to a silver‐ion‐loaded porous hollow‐fiber membrane
Authors: Shibasaki Akio , Irimoto Yasumitsu , Kim Min , Saito Kyoichi , Sugita Kazuyuki , Baba Takashi , Honjyo Isao , Moriyama Shigeru , Sugo Takanobu 
Published: May 2007

AbstractSilver ions were loaded at a density of 1 mmol/g onto a sulfonic acid group‐containing porous hollow‐fiber membrane prepared by radiation‐induced graft polymerization of an epoxy group‐containing monomer with subsequent modification by reaction with sodium sulfite. The permeability (i.e., permeation flow rate per inside surface area of the hollow fiber) of 4.6% wt/vol bonito oil ethyl ester solution in water/ethanol (7.5:92.5, vol/vol) was 1.7 m/h at a permeation pressure of 0.1 MPa. Breakthrough curves (i.e., concentration changes of the effluent with increasing effluent volume) obtained with docosahexaenoic acid ethyl ester (DHA‐Et) overlapped, irrespective of the permeation flow rate. This indicates that a higher rate of DHA‐Et adsorption onto the silver ions on the membrane was attained with increasing permeation flow rate. DHA‐Et, which was selectively bound to the membrane, was quantitatively eluted with acetonitrile as an eluent. The adsorption characteristics (i.e., binding rate, selectivity and durability for repeated use) of DHA‐Et using the silver ion loaded porous hollow‐fiber membrane were demonstrated. Feasibility studies will enable comparison of the purification cost of DHA‐Et among the other purification techniques.
Effect of moisture content on immobilized lipase‐catalyzed triacylglycerol hydrolysis under supercritical carbon dioxide flow in a tubular fixed‐bed reactor
Authors: Hampson J. W. , Foglia T. A. 
Published: May 2007

AbstractSurplus fats and oils were reacted with several lipases under supercritical fluid conditions for the purpose of obtaining value‐added products. Lipases, however, require sufficient moisture content to act as effective biocatalysts. An immobilized lipase from Candida antarctica was chosen to examine the rate of enzyme moisture loss under laboratory ambient conditions and also under supercritical fluid conditions. A more important aspect was to determine the effect of lipase moisture content on the hydrolysis of triacylglycerols under the same supercritical fluid conditions. Under ambient conditions at constant air flow, the immobilized lipase lost water at the rate of 4 to 5%/h, from 48.3% moisture to a final moisture content of 0.2%. Water is known not to be very soluble in supercritical carbon dioxide (SC‐CO2). Nevertheless, under supercritical fluid conditions of 60°C, 4000 psi, and carbon dioxide flow rates of 0.5 or 1 L/min measured as expanded gas, the enzyme moisture loss was approximately 2 to 6%/h. To determine the effect of moisture loss on enzymatic hydrolysis, lipase beds in a tubular reactor with moisture contents of 1.5 to 23.5% were reacted with tripalmitin under supercritical conditions. A lipase with an initial moisture content of 1.5% gave little evidence of hydrolysis whereas those containing 5.4 to 23.5% moisture content resulted in products that contained only palmitic acid and unreacted tripalmitin. Thus, optimal parameters for continuous lipase hydrolysis of tripalmitin require: enough enzyme moisture to compensate for complete substrate hydrolysis; sufficient enzyme moisture for losses due to water solubility in SC‐CO2; temperature and pressure sufficient to solubilize the tripalmitin; high carbon dioxide total flow to solubilize all the tripalmitin; and a relatively large enzyme bed volume to increase the solubilized substrate contact time with the enzyme.
Monitoring chemical interesterification
Authors: Liu Linsen , Lampert Dan 
Published: May 2007

AbstractChemical interesterification has long been used to modify oils and fats into functional products. Many chemical compounds can be used as the catalysts, such as sodium metal and sodium methoxide. With addition of the catalyst, the oil turns a well documented distinctive reddish brown. Many believe that this color compound may be the real catalyst in interesterification. The spectral changes of an oil undergoing interesterification were examined in the visible and ultraviolet wavelength ranges. An absorbance peak was found from 320–450 nm. Because this range is the wavelength of blue light, this absorption gives the oil a reddish brown color, the compensated color of blue light. The peak increases as the amount of sodium methoxide increases. To initiate and complete interesterification, the oil absorbance must reach levels of 0.4 and 1.0 at 374 nm, respectively. Controlled partial interesterification is now also possible by controlling the absorbance between 0.4 and 1.0. A novel patent‐pending technology, based on this observation, was developed to monitor the progress of interesterification on‐line using fiber optic technology. The reaction time and the dosage of sodium methoxide used for randomization have been significantly reduced on bench‐scale when using this new tool. Furthermore, the oils interesterified with monitoring have higher oxidative stability and tocopherol contents compared to those by conventional randomization.
Conversion of vegetable oil to biodiesel using immobilized Candida antarctica lipase
Authors: Shimada Yuji , Watanabe Yomi , Samukawa Taichi , Sugihara Akio , Noda Hideo , Fukuda Hideki , Tominaga Yoshio 
Published: May 2007

AbstractBiodiesel derived from vegetable oils has drawn considerable attention with increasing environmental consciousness. We attempted continuous methanolysis of vegetable oil by an enzymatic process. Immobilized Candida antarctica lipase was found to be the most effective for the methanolysis among lipases tested. The enzyme was inactivated by shaking in a mixture containing more than 1.5 molar equivalents of methanol against the oil. To fully convert the oil to its corresponding methyl esters, at least 3 molar equivalents of methanol are needed. Thus, the reaction was conducted by adding methanol stepwise to avoid lipase inactivation. The first step of the reaction was conducted at 30°C for 10 h in a mixture of oil/methanol (1:1, mol/mol) and 4% immobilized lipase with shaking at 130 oscillations/min. After more than 95% methanol was consumed in ester formation, a second molar equivalent of methanol was added and the reaction continued for 14 h. The third molar equivalent of methanol was finally added and the reaction continued for 24 h (total reaction time, 48 h). This three‐step process converted 98.4% of the oil to its corresponding methyl esters. To investigate the stability of the lipase, the three‐step methanolysis process was repeated by transferring the immobilized lipase to a fresh substrate mixture. As a result, more than 95% of the ester conversion was maintained even after 50 cycles of the reaction (100 d).
Rapid monitoring of transesterification and assessing biodiesel fuel quality by near‐infrared spectroscopy using a fiber‐optic probe
Authors: Knothe Gerhard 
Published: May 2007

AbstractVegetable oil esters, particularly methyl esters, are being explored and used as alternative diesel fuel (biodiesel). The transesterification reaction which yields the methyl esters can be monitored for completion by near‐infrared (NIR) spectroscopy using a fiber‐optic probe. Although the NIR method is less sensitive than gas chromatography (GC) for quantifying minor components, by correlation with existing GC or other analytical data, biodiesel fuel quality can be assessed through the NIR method. The NIR method is easier and faster to use than GC.
Preparation of ω‐hydroxynonanoic acid and its ester derivatives
Authors: Kula Jozef , Smigielski Krzysztof , Quang Thuat B. , Grzelak Iwona , Sikora Magdalena 
Published: May 2007

AbstractMethyl ricinoleate was ozonized in methanol or in acetic acid and the intermediate hydroperoxides were reduced electrochemically on Pb‐cathode to give 9‐hydroxynonanoic acid 1 in high yields. The acid 1 was also prepared by direct castor oil ozonolysis in methanol followed by sodium borohydride reduction of the intermediate hydroperoxides. The cost of the electricity for the electroreduction was at least 30 times lower as compared with sodium borohydride consumption. 9‐Hydroxynonanoic acid was then transformed to alkyl 9‐acetoxynonanoates 3a–3d, for which 1H nuclear magnetic reasonance, mass, and infrared spectra are given. Esterification of the hydroxy acid 1 with boric acid and pyrolysis of the resultant orthoborates produced 8‐nonenoic acid 4 in a 45% yield. Reaction of 4 with lower aliphatic alcohols in presence of Amberlyst 15 produced alkyl 8‐noneates 5a–5d along with some amounts of a cis/trans mixture of alkyl 7‐noneates.
Production and characterization of an extensive rapeseed protein hydrolysate
Authors: Vioque Javier , Sánchez‐Vioque Raul , Clemente Alfonso , Pedroche Justo , Bautista Juan , Millan Francisco 
Published: May 2007

AbstractRapeseed protein isolate has been used as starting material for the generation of an extensive protein hydrolysate. Protein hydrolysis was produced by using sequentially an endopeptidase (Alcalase) and an exopeptidase (Flavourzyme). The final hydrolysate has a 60% degree of hydrolysis and was completely soluble between pH values 2.5 and 7. Molecular weight profile of the protein hydrolysate was characterized by gel filtration chromatography. A reduction in protein size was observed during the hydrolysis process with accumulation of small peptides and free amino acids after Flavourzyme digestion. Amino acid composition of fractions with different molecular weights of the final hydrolysate was analyzed. Some of these fractions, enriched or poor in certain amino acids, could be used for supplementation or treatment of determined clinical syndromes.
γ‐Linolenic acid‐rich triacylglycerols derived from borage oil via lipase‐catalyzed reactions
Authors: Huang Fang‐Cheng , Ju Yi‐Hsu , Chiang Jen‐Chung 
Published: May 2007

Abstractγ‐Linolenic acid (GLA), a precursor of arachidonic acid, possesses physiological functions of modulating immune and inflammatory response. Highly purified GLA is desired both as a medicine and as an ingredient of cosmetics. In this work, urea fractionation and lipase‐catalyzed reactions were employed for the enrichment of GLA in borage oil. GLA content in free fatty acids from saponified borage oil can be increased from 23.6 to 94% by the method of urea fractionation. Partial hydrolysis of borage oil catalyzed by immobilized Candida rugosa lipase raises GLA content in the unhydrolyzed acylglycerols from 23.6 to 52.1%. The IM‐60 catalyzed acidolysis reaction between the GLA‐rich free fatty acid and the unhydrolyzed acylglycerols increases the GLA content in the acylglycerols from 52.1 to 75%. The acylglycerols in the reaction product contains ca. 90% triacylglycerol. The effects of temperature, water content, substrate weight ratio, and organic solvents on the GLA content in the acylglycerols were examined.
Enzymatic synthesis of symmetrical 1,3‐diacylglycerols by direct esterification of glycerol in solvent‐free system
Authors: Rosu Roxana , Yasui Mamoru , Iwasaki Yugo , Yamane Tsuneo 
Published: May 2007

Abstract1,3‐Diacylglycerols were synthesized by direct esterification of glycerol with free fatty acids in a solvent‐free system. Free fatty acids with relatively low melting points (<45°C) such as unsaturated and medium‐chain saturated fatty acids were used. With stoichiometric ratios of the reactants and water removal by evaporation at 3 mm Hg vacuum applied at 1 h and thereafter, the maximal 1,3‐diacylglycerol content in the reaction mixture was: 84.6% for 1,3‐dicaprylin, 84.4% for 1,3‐dicaprin, 74.3% for 1,3‐dilinolein, 71.7% for 1,3‐dieicosapentaenoin, 67.4% for 1,3‐dilaurin, and 61.1% for 1,3‐diolein. Some of the system's parameters (temperature, water removal, and molar ratio of the reactants) were optimized for the production of 1,3‐dicaprylin, and the maximal yield reached 98%. The product was used for the chemical synthesis of 1,3‐dicapryloyl‐2‐eicosapentaenoylglycerol. The yield after purification was 42%, and the purity of the triacylglycerol was 98% (both 1,3‐dicapryloyl‐2‐eicosapentaenoylglycerol and 1,2‐dicapryloyl‐3‐eicosapentaenoylglycerol included) by gas chromatographic analysis, of which 90% was the desired structured triacylglycerol (1,3‐dicapryloyl‐2‐eicosapentaenoylglycerol) as determined by silver ion high‐performance liquid chromatographic analysis.
Kinetics of enzymatic synthesis of isopropylidene glycerol esters by goat pregastric lipase
Authors: Lai Douglas T. , Hattori Norikatsu , O’Connor Charmian J. 
Published: May 2007

AbstractThe goat pregastric lipase‐catalyzed esterification of isopropylidene glycerol with caproic acid, to form isopropylidene glycerol caproate, followed a ping pong bi bi mechanism incorporating an acyl‐enzyme intermediate. The maximum rate was estimated to be 96 µmol min−1 mg−1 in isooctane at 35°C, and the Michaelis‐Menten constants for isopropylidene glycerol and caproic acid were 0.23 and 0.32 M, respectively. The catalyzed rate also correlated well with the partition coefficient of caproic acid between the organic and aqueous phases. The results suggest that the desolvation energy of the substrate from the bulk medium to the active site of the enzyme dominates the reaction rate for the enzyme‐catalyzed reaction in organic media.
Two‐dimensional surface properties of 2‐methoxy ethyl oleate at the air/water interface
Authors: Baskar Geetha , Venkatesan S. , Dhathathreyan Aruna , Mandal A. B. 
Published: May 2007

AbstractMethoxy ethyl oleate, a nonionic surfactant, has been investigated at the air/water interface for various surface properties by employing the Langmuir film balance technique. The ester forms an expanded isotherm at the air/water interface. The minimum area of packing (A0), initial area of increase of surface pressure (Ai), collapse pressure (πc), and area/molecule at collapse pressure (Ac) have been estimated from the isotherm curve. The higher compressibility coefficient (K) suggests that the ester forms a more expanded liquid film than the parent oleic acid. Besides, the ester film is fairly stable as suggested by only about 30% loss in area over a period of 20 min. The relaxation rates of the ester film at different surface pressures of 10, 15, and 20 mN·m−1 have been estimated from changes in the surface area/molecule with time. Interestingly, the surface area (54.2 Å2/molecule) that corresponds to a minimized structure projected for the ester, calculated theoretically, agrees reasonably well with the experimental value (57.2 Å2/molecule).
Practical nuclear magnetic resonance analysis of liquid oil in oilseeds: I factors affecting peak width
Authors: Reaney Martin J. T. , Tyler Nancy J. , Brown Keith 
Published: May 2007

AbstractIf proton nuclear magnetic resonance (NMR) spectra of single seeds can be improved, a rapid, low‐cost method of screening seeds for oil composition could be developed for use as a selection tool in plant breeding. NMR spectroscopy was performed on single seeds of borage, flax, and canola to evaluate methods for improving spectra quality (narrowing peak widths and increasing signal‐to‐noise ratio) to a degree necessary to measure differences among seeds in a breeding program. Immersion of seeds in a variety of solvents, including deuterated chloroform, deuterated acetone, deuterated dimethyl sulfoxide (DMSO) and completely fluorinated hydrocarbons (FC‐77), narrowed peaks obtained from seeds when compared with spectra from seeds analyzed in the absence of a solvent. Deuterated chloroform and FC‐77 were free of interfering solvent proton peaks while deuterated acetone and deuterated DMSO contributed interfering peaks. The spectra of dehulled seeds had narrower peak widths than did seeds with hulls. Treatments that decreased seed oil viscosity failed to substantially narrow spectra peak widths of seeds. High magnetic field strength did not improve the spectral quality of seeds, as peak widths increased with field strength. Conversely, low field strength limited resolution of oil spectra. Although the 300 MHz spectrum of vegetable oil had greater resolution (narrower peaks) than the 60 MHz spectrum, spectra of seeds produced at 60 MHz had superior resolution to 300 MHz spectra.
Rapid analysis of oxidized cholesterol derivatives by high‐performance liquid chromatography combined with diode‐array ultraviolet and evaporative laser light‐scattering detection
Authors: Osada Kyoichi , Ravandi Amir , Kuksis Arnis 
Published: May 2007

AbstractExtensive evidence of the deleterious biological effects of oxidized 5‐cholesten‐3β‐ol (cholesterol) derivatives has led to great interest in their detection. We observed that known oxidized cholesterol derivatives can be rapidly quantitated by combining reversed‐phase high‐performance liquid chromatography (HPLC) with ultraviolet (UV) absorption and evaporative laser light‐scattering (ELSD) detection. Using a 20 × 0.46 cm C18 HPLC column and methanol/acetonitrile (60:40, vol/vol) as the mobile phase at 1.0 mL/min, 10 species of oxidized cholesterol derivative were measured by UV (205, 234, and 280 nm) while 5‐cholestan‐5α,6α‐epoxy‐3β‐ol (5α‐epoxycholesterol), 5‐cholestan‐5β,6β‐epoxy‐3β‐ol (5β‐epoxycholesterol), and 5‐cholestan‐3β,5α,6β‐triol (cholestanetriol) were detected by only ELSD. The minimal limits of detection ranged from 100 to 500 ng depending on sterol and detector. The response was linear in the range 0–1000 or 0–2000 ng depending on detector. These oxidized cholesterol derivatives were also identified by HPLC/mass spectrometry analysis combined with UV detector. Heated tallow contained cholestanetriol, 5‐cholesten‐3β,7α‐diol (7α‐hydroxycholesterol), 5‐cholesten‐3β,7β‐diol (7β‐hydroxycholesterol), 5‐cholesten‐3β‐ol‐7‐one (7‐ketocholesterol), 5α‐ and 5β‐epoxycholesterols under the developed analysis condition. Photooxidized cholesterol had cholestanetriol, 7α‐ and 7β‐hydroxycholesterols and 3,5‐cholestadien‐7‐one. On the other hand, 7α‐ and 7β‐hydroxycholesterols, 7‐ketocholesterol, 5α‐ and 5β‐epoxycholesterols and 3,5‐cholestadien‐7‐one were observed in copper‐oxidized low‐density lipoprotein. Thus, this developed HPLC analysis method could be applied to identification of oxidized cholesterol derivatives in food and biological specimen.
High‐performance liquid chromatography evaluation of phenols in olive fruit, virgin olive oil, vegetation waters, and pomace and 1D‐ and 2D‐nuclear magnetic resonance characterization
Authors: Servili Maurizio , Baldioli Maura , Selvaggini Roberto , Miniati Enrico , Macchioni Alceo , Montedoro Gianfrancesco 
Published: May 2007

AbstractPhenolic compounds are the most important antioxidants of virgin olive oil. This paper reports on the application of solid phase extraction (SPE) in the separation of phenolic compounds from olive fruit, olive oil, and by‐products of the mechanical extraction of the oil and the complete spectroscopic characterization by nuclear magnetic resonance of demethyloleuropein and verbascoside extracted from olive fruit. SPE led to a higher recovery of phenolic compounds from olives than did liquid/liquid extraction. SPE also was used to separate phenolic compounds from pomaces and vegetation waters. Phenylacid and phenyl‐alcohol concentrations in extracts obtained from SPE and liquid/liquid extraction were not significantly different (P<0.05). The recovery of the dialdehydic form of elenolic acid linked to 3,4‐(dihydroxyphenyl)ethanol and an isomer of oleuropein aglycon, however, was low.
Enzymatic modification of triacylglycerols of high eicosapentaenoic and docosahexaenoic acids content to produce structured lipids
Authors: Jennings Brenda H. , Akoh Casimir C. 
Published: May 2007

AbstractImmobilized lipase, IM60, from Rhizomucor miehei was used as a biocatalyst for the incorporation of capric acid (C10:0) into fish oil originally containing 40.9 mol% eicosapentaenoic (20:5n‐3) and 33.0 mol% docosahexaenoic (22:6n‐3) acid. Acidolysis was performed with and without organic solvent. Pancreatic lipase‐catalyzed sn‐2 positional analysis was performed after enzymatic modification. Tocopherol analysis was performed before and after enzymatic modification. Products were analyzed by gas‐liquid chromatography. After a 24‐h incubation in hexane, there was an average of 43.0±1.6 mol% incorporation of C10:0 into fish oil, while 20:5 and 22:6 decreased to 27.8±2.2 and 23.5±1.3 mol%, respectively. The solvent‐free reaction produced an average of 31.8±8.5 mol% C10:0 incorporation, while 20:5 and 22:6 decreased to 33.2±3.3 and 28.3±3.9 mol%, respectively. The effect of incubation time, substrate molar ratio, enzyme load, and added water were also studied. In general, as the enzyme load, molar ratio, and incubation time increased, mol% C10:0 incorporation also increased. The optimal mol% C10:0 incorporation was 41.2% at 48 h for the reaction in hexane and 46.4% at 72 h for the solvent‐free reaction. The highest C10:0 incorporation (65.4 mol%) occurred at a molar ratio of 1:8 (fish oil triacylglycerols/capric acid) in hexane. For the solvent‐free reaction, the optimal mol% C10:0 incorporation (56.1 mol%) occurred at a molar ratio of 1:6. An enzyme load of 10% gave the highest mol% C10:0 incorporation (41.4 mol%) in hexane; the highest incorporation (38.3 mol%) for the solvent‐free reaction occurred at 15% enzyme load. Mol% incorporation of C10:0 declined with increasing amounts of added water. The optimal mol% C10:0 incorporation occurred at 1% added water (47.9 mol%) for the reaction in hexane, and at zero added water for the solvent‐free reaction (21.8 mol%). Fish oil containing capric acid was successfully produced and may be nutritionally more beneficial than unmodified oil.
Enzymatic synthesis of l‐menthyl esters in organic solvent‐free system
Authors: Shimada Yuji , Hirota Yoshinori , Baba Takashi , Kato Shinichiro , Sugihara Akio , Moriyama Shigeru , Tominaga Yoshio , Terai Tadamasa 
Published: May 2007

Abstractl‐Menthol has been widely used as a food additive and an ingredient of cosmetics, and it is esterified to moderate the strong flavor. We attempted esterification of l‐menthol with long‐chain unsaturated fatty acid in an organic solvent‐free enzymatic system. Commercially available lipases were screened, and Candida rugosa lipase was selected as a catalyst. Several factors affecting the esterification were investigated, and the reaction conditions were determined as follows: A reaction mixture of l‐menthol/fatty acid (1:3, mol/mol), 30% water, and 700 units of the lipase per gram of reaction mixture was incubated at 30°C with stirring. After 24 h under these conditions, the esterification extents of l‐menthol with oleic, linoleic, and α‐linolenic acids reached 96, 88, and 95%, respectively. The structure of the esterified product was confirmed by mass, infrared, and nuclear magnetic resonance spectroscopies. Bacause Candida lipase acted strongly on l‐menthol and very weakly on d‐menthol, dl‐menthol was esterified with oleic acid under the same conditions. The reaction showed high enantioselectivity; the enantiomeric ratio (E) was 31, and enantiomeric excess (ee) of l‐menthyl oleate reached 88% after 32 h.