bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of oxidation under accelerated conditions on fuel properties of methyl soyate (biodiesel)
Authors: Dunn Robert O. 
Published: November 2006

AbstractBiodiesel derived from transesterification of soybean oil and methanol is an attractive alternative fuel for combustion in direct‐injection compression ignition (diesel) engines. During long‐term storage, oxidation due to contact with air (autoxidation) presents a legitimate concern with respect to maintaining fuel quality of biodiesel. This work examines the effects of oxidation under controlled accelerated conditions on fuel properties of methyl soyate (SME). SME samples from four separate sources with varying storage histories were oxidized at elevated temperature under a 0.5 standard cm3/min air purge and with continuous stirring. Results showed that reaction time significantly affects kinematic viscosity (ν). With respect to increasing reaction temperature, ν, acid value (AV), PV, and specific gravity (SG) increased significantly, whereas cold flow properties were minimally affected for temperatures up to 150°C. Antioxidants TBHQ and α‐tocopherol showed beneficial effects on retarding oxidative degradation of SME under conditions of this study. Results indicated that ν and AV have the best potential as parameters for timely and easy monitoring of biodiesel fuel quality during storage.
Effect of scraped‐surface tube cooler temperatures on the physical properties of palm oil margarine
Authors: Miskandar M. S. , Che Man Y. B. , Yusoff M. S. A. , Abdul Rahman R. 
Published: November 2006

AbstractThe effects of scraped‐surface tube cooler temperatures on the isothermal solid fat content (SFC) of palm oil margarine during processing and on margarine consistency (yield value, g/cm2), SFC, and polymorphic changes in storage were studied. SFC was measured in the mixing tank after leaving the tube cooler and the pin worker. The SFC at the tube cooler exit was proportional to the amount of cooling; a higher SFC was produced by more extreme cooling treatment. The SFC of all margarines were reduced in the pin worker, and the reduction was related to the initial SFC profile of palm oil. Margarine samples were stored at 28°C for 28 d and tested daily. Margarine processed at 25°C in the tube cooler had the highest consistency and the least change in SFC, but by the second week crystals had transformed into the β form. Uniform product consistency and SFC were observed in margarines processed at 20 and 15°C. These margarines retained the β′ crystal form for 3 and 4 wk, respectively. The best palm oil margarine was obtained with a tube cooler temperature of 15°C and a residence time of 1.8 min.
Immersion vs. percolation in the extraction of oil from oleaginous seeds
Authors: Pramparo M. , Gregory S. , Mattea M. 
Published: November 2006

AbstractThe influence of the two contact modes, percolation and immersion, during the extraction of oilseeds by means of a solvent are presented. Experiments were performed in lab‐scale equipment with soybean flakes, arranged in beds that reproduce these two contact modes. The extractions were carried out with hexane at constant temperature. To simulate the performance of shallow‐and deep‐bed extractors, two different bed height/diameter ratios were used. The experimental results are explained in terms of the basic transfer phenomena that occur during extraction. These phenomena are addressed to develop a mathematical model, which is used to simulate extraction under both contact modes. The immersion scheme yielded greater efficiency than the percolation mode to extract soybean flakes for the two bed height/diameter ratios studied. The mathematical model predicts very well the experimental findings. It also predicts the solvent retained by the solid mass after extracting the oil.
Rheological characterization of yellow grease and poultry fat
Authors: Goodrum John W. , Geller Daniel P. , Adams Thomas T. 
Published: November 2006

AbstractThe rheological properties of yellow grease and poultry fat and their liquid density at 25.0°C were experimentally determined. Dynamic viscosities of these industrial recycled fat products were measured for shear rates of 0.65 to 32.34 s−1 at temperatures of 15.6 to 71.1°C. The resulting measurements were fitted to a power law model to obtain values for the consistency coefficient and the flow behavior index. The data was also fit to Andrade's equation to relate viscosity to temperature. These results indicated pseudoplastic flow behavior for both products, with increasing non‐Newtonian behavior at higher temperatures and shear rates.
GC determination of synthetic hydrocarbon‐based thermal heating fluid in vegetable oils
Authors: Mon M. H. , Tang T. S. , Tan G. H. 
Published: November 2006

AbstractA combination of alumina column chromatography and GC procedures was developed for the determination of synthetic hydrocarbon‐based thermal heating fluid (trademarked as Therminol 55™) in vegetable oils. In each run, 3 g of sample solution was loaded onto the alumina (50 g) column and was eluted with 200 mL hexane. The eluate was then concentrated to 1 mL with the aid of a nitrogen stream prior to GC analysis. The GC chromatogram of the thermal heating fluid was characterized by the presence of a bell‐shaped hump that could not be resolved into individual peaks. The lowest detection limit based on various spiked palm olein samples was 20 μg/g. The CV obtained were 6.5–8.9% for the intra‐day study and 8.1–9.7% for the inter‐day study. Overall recoveries of these samples ranged from 68.0 to 85.7% and the method was found to be good enough for quality control purposes.
Effect of processing conditions on microstructure of milk fat fraction/sunflower oil blends
Authors: Martini S. , Herrera M. L. , Hartel R. W. 
Published: November 2006

AbstractThe effect of processing conditions on the crystallization of blends of a high‐melting milk fat fraction and sunflower oil was investigated. Two cooling rates were selected for all studies: 0.1°C/min (slow rate) and 5.5°C/min (fast rate). Blends were crystallized in two conditions: (i) with agitation in an 80‐mL crystallizer (dynamic), and (ii) on a microscope slide without agitation (static). The selected crystallization temperatures were 25, 30, and 35°C for both cooling rates. Photographs of the development of crystals with time were taken in both static and dynamic conditions, and the crystal size distribution was determined at the moment that the laser signal reached its peak. Photographs showed that when samples were cooled slowly, crystals had a more regular boundary, appeared to be more densely arranged, and were larger. In dynamic conditions, crystal sizes were smaller and the background contained numerous small crystals, which were not found in statically crystallized samples. All images showed that crystals were not single crystals, but grew by accretion.
Monitoring PV in corn and soybean oils by NIR spectroscopy
Authors: Yildiz Gülgün , Wehling Randy L. , Cuppett Susan L. 
Published: November 2006

AbstractNIR spectroscopy was used successfully in our laboratory to monitor oxidation levels in vegetable oils. Calibration models were developed to measure PV in both soy and corn oils, using partial least squares (PLS) regression and forward stepwise multiple linear regression, from NIR transmission spectra. PV can be measured successfully in both corn and soy oils using a single calibration. The most successful calibration was based on PLS regression of first derivative spectra. When this calibration was applied to validation sample sets containing equal numbers of corn and soy oil samples, with PV ranging from 0 to 20 meq/kg, a correlation coefficient of 0.99 between titration and NIR values was obtained, with a standard error of prediction equal to 0.72 meq/kg. For both types of oil, changes occurred in the 2068 nm region of the NIR spectra as oxidation levels increased. These changes appear to be associated with the formation of hydroperoxides during oxidation of the oils.
FA composition and regiospecific analysis of Acer saccharum (sugar maple tree) and Acer saccharinum (silver maple tree) seed oils
Authors: Destaillats Frédéric , Jean‐Denis Jean B. , Arul Joseph , Wolff Robert L. , Angers Paul 
Published: November 2006

AbstractGC analysis was performed to determine regiospecific distribution and FA composition in seed oils of the Aceraceae species, Acer saccharum and A. saccharinum. The oil content in the seeds was low at 5.0% in A. saccharum and 5.8% in A. saccharinum, and the main FA were linoleic (30.8 and 29.4%), oleic (21.3 and 27.6%), palmitic (10.1 and 10.5%), and cis‐vaccenic (9.4 and 7.9%) acids, respectively. In addition, both oils contained long‐chain monoenes of the n−9 and n−7 groups, including 11‐eicosenoic, 13‐docosenoic, 15‐tetracosenoic, 13‐eicosenoic, and 15‐docosenoic acids, whereas γ‐linolenic acid accounted for 0.8% of total FA in A. saccharum, and 0.5% in A. saccharinum. Regiospecific analysis, performed using the methodology of dibutyroyl derivatives of MAG, indicated that linoleic, oleic, and linolenic acids were mainly esterified at the internal position of TAG in both seed oils, whereas long‐chain monoenes of the n−7 group were almost exclusively esterified on the external positions.
Effect of oil degradation during frying on the color of fried, battered squid rings
Authors: Baixauli R. , Salvador A. , Fiszman S. M. , Calvo C. 
Published: November 2006

AbstractOil degradation caused by the number of fryings performed and the effect of oil degradation on the color of fried battered squid rings were studied. Spectrophotometric techniques with absorbance in the UV and visible ranges, and iodine, peroxide, and acid values were used to determine oil degradation. Determination of various CIELAB parameters in order to study the external color of the fried battered squid rings revealed no differences in color due to the number of fryings. A study of the color of the battered squid rings at various frying times and temperatures showed significant differences for both variables. Although there was some degradation in the oil after 20 fryings, appearing as a slight darkening, it did not affect the final color of the fried, battered squid rings.
Correlation of viscosities of vegetable oil blends with selected esters and hydrocarbons
Authors: Erhan S. Z. , Asadauskas S. , Adhvaryu A. 
Published: November 2006

AbstractBlending is often used to reduce the viscosity of vegetable oil lubricants. Experimental rheological results were compared with traditional blending charts and calculation methods. Kinematic viscosities of 90% oleic sunflower, canola, and soybean oils blended with adipates, oleates, polyalphaolefins, and mineral oil were determined at 40°C using capillary viscometers. Blending charts related the viscosities to blend composition with 5% inaccuracy compared with more than 10% deviation made by the cubic equation of Kendall and Monroe. Even more accurate and simpler correlations could be derived. A semilog relationship between viscosities and composition was more accurate than a cubic model. Higher accuracy was also achieved when relating viscosities to volume fractions rather than to weight or mole fractions. Mineral oil blends did not follow the observed rules.
Observations on the estimation of scavenging activity of phenolic compounds using rapid 1,1‐diphenyl‐2‐picrylhydrazyl (DPPH•) tests
Authors: Nenadis Nikolaos , Tsimidou Maria 
Published: November 2006

AbstractRapid 1,1‐diphenyl‐2‐picrylhydrazyl (DPPH•) tests are often applied to classify the scavenging activity of phenolic compounds (AH). Published analytical protocols differ in more than one experimental condition, and results for the relative order or magnitude of activity are often contradictory. In this work, parameters such as duration of test, [AH]/[DPPH•] molar ratio, and solvent effects were examined and discussed. The test duration and the value of the [AH]/[DPPH•] ratio did not influence the order of activity among tested antioxidants. Ethanol, commonly used as solvent in such tests, was compared with acetonitrile and tert‐butyl alcohol. Solvent properties such as the ability to form hydrogen bonds with the AH seem to influence the level of the relative activity (%RSA). Higher %RSA values were observed in ethanol. The activity of the most polar compounds was affected the most, and in some cases (caffeic, dihydrocaffeic, and rosmarinic acids) the order of activity was changed owing to different kinetics. Standardization of the analytical protocol should include a 20‐min reaction period and a molar ratio that permits attainment of a 60–80% RSA value for the most potent antioxidant. Solvent choice is critical for classifying activity. Safe classification can be based only on results from kinetic studies.
Synthesis of triglyceride estolides from lesquerella and castor oils
Authors: Isbell Terry A. , Cermak Steven C. 
Published: November 2006

AbstractTriglyceride (TG) estolides were synthesized from the hydroxy moieties of lesquerella and castor oils with oleic acid. Complete esterification of the hydroxy oils was possible when a slight excess of oleic acid was employed (1 to 1.5 mole equivalents). The estolides could be formed in the absence of catalyst at 175 to 250°C under vacuum or a nitrogen atmosphere. The optimal reaction conditions were found to be under vacuum at 200°C for 12 h for lesquerella and 24 h for castor oil. The lesquerella esterification reaction was completed in half the time of the for castor and with lower equivalents of oleic acid due to the difunctional hydroxy nature of lesquerella TG compared to the trifunctional nature of castor TG. Interesterification or dehydration of the resulting estolides to conjugated FA was not a significant side reaction, with only a slight amount of dehydration occurring at the highest temperature studied, 250°C. Use of a mineral‐or Lewis‐acid catalyst increased the rate of TG‐estolide formation at 75°C but resulted in the formation of a dark oil, and the reaction did not go to completion in 24 h. Estolide numbers (i.e., degree of estolide formation) for the reaction and characterization of the products were made by 1H NMR and 13C NMR. The decrease in the hydroxy methine signal at 3.55 ppm was used to quantify the degree of esterification by comparing this integral to the integral of the alpha methylene protons on the glycerine at 4.28 and 4.13 ppm.
Concentration of sterols and tocopherols from olive oil with supercritical carbon dioxide
Authors: Ibáñez Elena , Hurtado Benavides Andrés M. , Señoráns Francisco J. , Reglero Guillermo 
Published: November 2006

AbstractA process based on the use of a semicontinuous countercurrent supercritical fluid extraction has been developed to isolate and concentrate minor compounds, such as sterols and tocopherols, from olive oil. In the present work, an evaluation of the efficiency of different random packing materials (Raschig rings, Dixon rings, Fenske rings, and glass beads) to selectively separate sterols and tocopherols from olive oil has been performed. Parameters such as recovery, enrichment, and selectivity vs. TG are discussed. Considering the importance of supercritical fluid extraction as a clean processing technology and the interest in minor compounds with nutraceutical properties from olive oil, the process studied represents an alternative to the reuse of low‐quality olive oil to extract high added‐value products.
Microwave‐assisted catfish liver oil extraction and FA analysis
Authors: Sathivel Subramaniam , Prinyawiwatkul Witoon , King Joan M. , Grimm Casey C. , Lloyd Steven 
Published: November 2006

AbstractFA profiles of catfish liver oils were analyzed after microwave‐assisted (without solvent extraction) and/or conventional (with solvent extraction) preparation methods. Microwave heating of the smaples was performed at 100, 80, 60, or 40% power at 1,000 W and 2,450 MHz, each for 80, 60, 40, or 20 s. Significant differences in the content of recovered FA were observed among the microwave‐heated samples, except for C20∶0 and C20∶4. Recovery of C16∶0, C20∶0, and C20∶4 from the samples analyzed by the microwave‐assisted method was lower than that of the samples analyzed by the conventional method. Much greater recovery was observed for C18∶1, C18∶2, and C22∶6; however, the recovery was not different from or was only slightly lower than that of the conventional method when microwave heating was set at 40% power for 20 s. This was also observed for the total unsaturated or saturated FA. Compared to other microwave treatments, heating at 100% power for 80 s yielded the greatest recovery of C14∶0, C18∶0, C18∶1, C18∶2, C18∶3, C20∶1, C20∶2, and C22∶6.
Characterization of a double emulsion system (oil‐in‐water‐in‐oil emulsion) with low solid fats: Microstructure
Authors: Jahaniaval Firouz , Kakuda Yukio , Abraham Varghese 
Published: November 2006

AbstractA double emulsion system [oil‐in‐water‐in‐oil (O/W/O)] with 16.3% (w/w) water and 83% (w/w) oil was prepared and stabilized using a novel method of mixing two oil‐in‐water (O/W) emulsions together. The first emulsion consisted of 85% (w/w) liquid canola oil, 14.4%(w/w) water, 0.5% (w/w) sodium caseinate, and 0.1% (w/w) lecithin and the second emulsion contained 73% (w/w) canola oil, 8% (w/w) palm‐cotton stearin (50∶50), 0.2% (w/w) lecithin, 18.2% (w/w) water, and 0.6% (w/w) sodium caseinate. Mixing the two emulsions (50∶50) by weight produced a product with 79% (w/w) liquid canola oil and 4% (w/w) palm‐cotton stearin. The two O/W emulsions were prepared separately at 50°C, mixed together at 45°C for 2–5 min, and then supercooled in a −5°C ice/salt bath while mixing at low shear rates (2,000–3,000 rpm). Under supercooling conditions the fat globules in the second emulsion (containing liquid oil and stearin) began to break down as a result of fat crystal growth and shearing action and release plastic fat. During this stage, the continuous aqueous phase underwent a phase transition and the emulsion viscosity dropped from 37,000–50,000 to 250 cP. The released plastic fat continued to harden as the temperature dropped and stabilized the first O/W emulsion (containing only liquid oil). The low shear rate mixing was stopped when the temperature dropped below 15°C and before the O/W/O emulsion hardens. Microstructural analysis of the first emulsion before and after supercooling showed essentially intact fat globules. The microstructure of the second emulsion before supercooling showed the same intact globules as the first emulsion, but after supercooling, an amorphous mass with only a few intact globules was seen. By mixing the two emulsions together and supercooling, a stable O/W/O emulsion was formed with plastic fat as the continuous phase and the first O/W emulsion as the dispersed phase.
Enzymatic fractionation and enrichment of n−9 PUFA
Authors: Shimada Yuji , Watanabe Yomi , Kawashima Akiko , Akimoto Kengo , Fujikawa Shigeaki , Tominaga Yoshio , Sugihara Akio 
Published: November 2006

AbstractA single‐cell oil from a Mortierella alpina mutant (TGM17 oil) contains n−9 PUFA: 14.3 wt% 6,9‐octadecadienoic acid (18∶2n−9; n−9 LnA) and 17.1 wt% Mead acid (20∶3n−9; MA). Lipase screening indicated that Pseudomonas aeruginosa lipase acted strongly on n−9 LnA and weakly on MA, and Candida rugosa lipase acted weakly on the two PUFA. Hence, fractionation and enrichment of the two FA were conducted with the lipases. The first step was selective hydrolysis of IGM17 oil with P. aeruginosa lipase. The hydrolysis fractionated the oil into FFA containing 20.4 wt% n−9 LnA and 6.3 wt% MA, and acylglycerols containing 10.7 wt% n−9 LnA and 23.7 wt% MA. The FFA fraction was used for preparation of n−9 LnA‐rich FFA. After removal of saturated FA, the FFA were esterified with lauryl alcohol (LauOH) using C. rugosa lipase. Two selective esterifications increased the n−9 LnA content to 54.0 wt% with 38.2% recovery of the initial content of TGM17 oil. The acylglycerol fraction obtained in the hydrolysis with P. aeruginosa lipase was used for preparation of MA‐rich FFA. The acylglycerol fraction was hydrolyzed under alkaline conditions, and saturated FA were eliminated by urea adduct fractionation. Two selective esterifications of the FFA with LauOH increased the MA content to 60.2 wt% with 53.5% recovery. Thus, the two‐step enzymatic process was effective for fractionation and enrichment of n−9 LnA and MA.
Protein solubility characteristics of commercial soy protein products
Authors: Lee K. H. , Ryu H. S. , Rhee K. C. 
Published: November 2006

AbstractSolubility characteristics of commerical soy protein products (flours, concentrates, and isolates) were determined under various conditions. From the solubility profiles at various pH values and NaCl concentrations, soy protein isolates can be divided into three groups. One group had high solubility near the pl. Another group had low solubility near the pl, but high solubility at pH 11. The third group had low solubility even at pH 11. Except for the hydrolyzed products, the protein solubilities of the soy protein products at various salt concentrations were very low. Temperature did not significantly affect the protein solubility, although a few products showed more than a 20% increase at temperatures >50°C. Soy protein concentrates and soy protein isolates showed similar solubility profiles. The proteins in all commercial products (except flours) tested were denatured, as evident from the solubility profiles in the presence of salt and the enthalpy values from DSC.
Monitoring milk fat fractionation: Filtration properties and crystallization kinetics
Authors: Vanhoutte Bert , Dewettinck Koen , Vanlerberghe Brecht , Huyghebaert André 
Published: November 2006

AbstractThe effect of fractionation temperature, residence time, and agitation rate on the chemical composition of the stearin and olein milk fat fractions was studied. During fractionation, filtration properties of the crystal suspension were monitored; crystallization kinetics was determined by 1H NMR. Higher fractionation temperatures result in a lower stearin yield, more oil entrapment, and a lower final solid fat content of the crystal suspension. On the other hand, the chemical composition of the resulting fractions is not influenced. Longer residence times lead to longer filtration times and lower oil entrapment, whereas the yield is not affected. Longer residence times induced lower growth rates, but chemical composition is not influenced. Agitation rates varying from 10 to 15 rpm have no influence on the chemical composition of stearin and olein milk fat fractions. Higher agitation rates decrease the filtration quality and increase stearin yield, causing a softer stearin. In designing and monitoring milk fat fractionation, filtration experiments and the assessment of crystallization kinetics are valuable techniques, but compositional chemical analysis is not favorable.
Identification and quantification of neuroactive N‐acylethanolamines in cottonseed processing fractions
Authors: Chapman Kent D. , Venables Barney J. , Dian Emese E. , Gross Guenter W. 
Published: November 2006

AbstractN‐Acylethanolamines (NAE) include lipid species that have been identified as potent endocannabinoid mediators in mammalian physiology. Here we have isolated, identified, and quantified the NAE naturally present in cottonseed refining fractions. Among the fractions examined, NAE were most prevalent in finished meal, totaling approximately 8.5 μg/g fresh weight. These NAE were identified by GC‐MS as ethanolamides of myristic (14∶0), palmitic (16∶0), stearic (18∶0), oleic (18∶1), and linoleic (18∶2) acids, with NAE18∶2 and NAE16∶0 being the most abundant. NAE were not detected in refined, bleached, and deodorized oil, although they were present in less‐purified oil fractions. At micromolar concentrations, both NAE18∶2 and NAE16∶0 exhibited neuromodulatory activities in murine neuronal networks cultured and evaluated on microelectrode arrays. It follows that oilseed processing fractions may represent a novel, natural source of bioactive NAE.