bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of Alcalase™ on olive pomace protein extraction
Authors: Vioque J. , Clemente A. , Sánchez‐Vioque R. , Pedroche J. , Millán F. 
Published: November 2006

AbstractThe effect of Alcalase™ treatment on olive pomace protein extraction has been studied. Alcalase improves protein extraction from 5 to 30% of total protein. This improvement is not accompained by an increase in degree of protein hydrolysis, probably because protease activity is inhibited by secondary metabolites and the substrate is highly denatured and resistant to hydrolysis. The increase in protein extraction is attributed to fiber solubilization as a result of secondary activities of Alcalase. Protein extracts with a high content of soluble fiber have improved functional properties, with respect to olive pomace, such as water and oil absorption. Emulsifying and foaming activities were inappreciable. The products obtained represent a suitable source of soluble fiber and protein and may contribute to the improvement of the economic status of olive pomace by‐product.
Isolation and separation of tocopherols from olive by‐products with supercritical fluids
Authors: Ibáñez E. , Palacios J. , Señoráns F. J. , Santa‐María G. , Tabera J. , Reglero G. 
Published: November 2006

AbstractSupercritical fluid extraction of olive pomace, the semisolid residue obtained using two‐phase olive oil production systems, and supercritical fluid chromatographic separation of the extracts were performed to study the content of tocopherols, a group of compounds of interest for the food industry owing to their antioxidant activity. The developed method consists of supercritical CO2 extraction at pilot plant scale and subsequent fractionation by two successive depressurizations. Enrichment of α‐, β‐, and γ‐tocopherol was achieved in separator 2 when working at low densities in the first separator. Fractions obtained using high densities in separator 1 contained major proportions of triglycerides, waxes, and sterols. Tocopherols from olive by‐products were separated and quantified in an environmentally friendly way by using supercritical fluid chromatography with packed capillary columns coated with polyethylene glycol and neat CO2 according to a method previously optimized in our laboratory. The studied olive by‐products can be considered a natural source of antioxidants because substantial concentration of tocopherols have been obtained in the extracts. The isolation and separation of tocopherols from olive pomace by applying supercritical fluid technology provides an interesting approach to exploit such by‐products in an environmentally friendly way.
The effect of the refining process on the interfacial properties of palm oil
Authors: Ho C. C. , Chow M. C. 
Published: November 2006

AbstractThe interfacial tension of palm oil against water at 60°C was determined in the presence of monoglycerides with (i) different acyl chain lengths, (ii) the same acyl chain length but with different unsaturation, and (iii) different phospholipids. The interfacial tensions of the oil/water interface were depressed, albeit to different extents, by the presence of these substances, depending on the acyl chain length, unsaturation, and the chemical structure of the species adsorbed. The adsorption of the saturated monoglycerides C12∶0, C14∶0, C16∶0, C18∶0 and the unsaturated monoglycerides of C18∶1 and C18∶3 is consistent with a Langmuir isotherm at the palm oil/water interface. However, fitting of the data for C18∶2, l‐α‐phosphatidylcholine, and lysophosphatidylcholine to the Langmuir isotherm is less satisfactory. The surface areas of the materials adsorbed at the palm oil/water interface are much larger than those of liquid condensed films and closer to those for liquid expanded films. The influence of the nature of the oil (triglycerides), the minor components in the oil, and thier interactions with the added lipids at the oil/water interface are briefly discussed. The effect of the refining process on the interfacial properties of palm oil against water was also studied. The efficiency of the refining process in minor oil contaminants’ removal and the quality of the oil obtained as reflected by the interfacial properties of the oil is discussed.
Urea‐based fractionation of seed oil samples containing fatty acids and acylglycerols of polyunsaturated and hydroxy fatty acids
Authors: Hayes Douglas G. , Van Alstine James M. , Setterwall Fredrik 
Published: November 2006

AbstractThe selectivity and efficiency of urea complex (UC) formation‐based fractionation of free fatty acids (FFA) were examined. A rapid, simple, and inexpensive procedure recently developed for urea fractionation was applied to lipid mixtures containing various polyunsaturated and hydroxy FFA species. Urea treatment proved useful for isolating polyunsaturated FFA (PUFA) from FFA derived from fish, borage, and linseed oils by removal of saturated and monounsaturated FFA, but was not effective for isolating hydroxy FFA from the FFA derived from castor, Lesquerella, and Dimorphotheca oils. In situations where FFA within the crystalline or UC phase were rich in PUFA, the urea/FFA mole ratio of the UC was relatively higher, with lower recovery of FFA in this phase. The distribution of urea between the crystalline phase and the solvent was not significantly affected by the FFA composition of feed nor the overall ratio of FFA to urea. It was strongly dependent on the overall mass fraction of solvent. Phospholipids and mono‐, di‐, and triacylglycerols were poor templates for UC formation relative to FFA. Their inclusion in acylglycerol mixtures containing FFA reduced UC formation.
Determination of oxidative stability of lipids in solid samples
Authors: Tian Kang , Dasgupta Purnendu K. , Shermer William D. 
Published: November 2006

AbstractA gas‐phase flow injection analysis (FIA) method for the direct determination of the oxidative stability of solid fat/oil samples is described. Samples are confined with a low level of oxygen in a reactor of adjustable temperature. The oxygen consumption by the sample is automatically monitored after a preset period. The temperature‐dependent data exhibit Arrhenius behavior. Normally, it is difficult to directly determine the stability at ambient temperatures because of inordinately long time requirements. The close correspondence to Arrhenius behavior makes it possible to use the results obtained at higher temperature to calculate the stability of samples at lower temperature conditions, such as at ambient storage temperature. The effects of sample size, sample particle size, sample fat content and the reproducibility of the method over time were studied using synthetic and bone meal samples. The oxygen consumption was found to be linearly dependent on the amount of sample taken, inversely dependent on the particle diameter, and independent of the exact lipid content, given some minimum lipid content. The results exhibited high day‐to‐day reproducibility. The gasphase FIA system developed in this work is easy to operate. Compared with the currently used method, the sample throughput rate is much faster (2–3h for complete multitemperature characterization of a sample) and the sample requirement is much lower (∼1 g). Furthermore, it eliminates the need to extract and recover the fat from the sample for further processing as is required by the other methods commonly used to measure oxidative stability.
Fatty acid derivatives as corrosion inhibitors for mild steel and oil‐well tubular steel in 15% boiling hydrochloric acid
Authors: Quaraishi M. A. , Jamal Danish , Tariq Saeed Mohd 
Published: November 2006

AbstractSelected hydrazides and thiosemicarbazides of fatty acids with 11, 12, and 18 carbon atoms were synthesized and evaluated as corrosion inhibitors on mild steel and oil‐well steel (N‐80) in boiling 15% hydrochloric acid solution, by weight loss method. Potentiodynamic polarization studies carried out on mild steel and N‐80 steel at room temperature showed that all the tested compounds are of mixed type. Adsorption studies showed that all the investigated compounds followed Temkin's adsorption isotherm.
The speed of sound and isentropic bulk modulus of biodiesel at 21°C from atmospheric pressure to 35 MPa
Authors: Tat Mustafa E. , Van Gerpen Jon H. , Soylu Seref , Canakci Mustafa , Monyem Abdul , Wormley Samuel 
Published: November 2006

AbstractBiodiesel, an alternative diesel fuel consisting of the alkyl monoesters of fatty acids from vegetable oils and animal fats, can be used in existing diesel engines without modification. However, property changes associated with the differences in chemical structure between biodiesel and petroleumbased diesel fuel may change the engine's injection timing. These injection timing changes can change the exhaust emissions and performance from the optimized settings chosen by the engine manufacturer. This study presents the results of measurements of the speed of sound and the isentropic bulk modulus for methyl and ethyl esters of fatty acids from soybean oil and compares them with No. 1 and No. 2 diesel fuel. Data are presented at 21±1°C and for pressures from atmospheric to 34.74 MPa. The results indicate that the speed of sound and bulk modulus of the monoesters of soybean oil are higher than those for diesel fuel and these can cause changes in the fuel injection timing of diesel engines. Linear equations were used to fit the data as a function of pressure, and the correlation constants are given.
Characterization of semisolid fats and edible oils by Fourier transform infrared photoacoustic spectroscopy
Authors: Yang Hong , Irudayaraj Joseph 
Published: November 2006

AbstractThe potential of Fourier transform infrared photoacoustic spectroscopy (FTIR‐PAS) for the analysis of semisolid fat and edible oil was demonstrated with butter, soybean oil, and lard as representative materials. Results of Fourier transform infrared attenuated total reflectance (FTIR‐ATR) spectroscopy analysis was compared with FTIR‐PAS results. The PAS technique is simple and requires no sample preparation unlike ATR. Optimal PAS instrumental parameters for obtaining quality spectra are a scanning speed of 5 kHz, number of scans of 256 scans/sample, and a resolution of 4 cm−1. The PAS spectra of soybean oil and lard are similar because they have similar functional groups. Results for soybean oil compare well with those available in the literature. The ATR spectra of butter were better than those from its PAS counterpart. Functional groups corresponding to vibration mode and intensity are provided for soybean oil and lard.
Crystallization kinetics of palm stearin in blends with sesame seed oil
Authors: Toro‐Vazquez J. F. , Briceño‐Montelongo M. , Dibildox‐Alvarado E. , Charó‐Alonso M. , Reyes‐Hernández J. 
Published: November 2006

AbstractThis study investigates the crystallization kinetics of palm stearin (PS), a palm oil fraction, in blends with sesame seed oil. The results indicate that the crystallization behavior of PS in sesame oil is mainly associated with the crystallization of tripalmitin. Therefore, crystallization of blends of 26, 42, 60, and 80% (wt/vol) PS in sesame oil was described by equations developed for simpler systems (e.g., Fisher and Turnbull equation). The isothermal crystallization, melting profile, and fitting of the kinetics of nucleation to the Fisher and Turnbull equation showed that the 26, 42, and 60% PS/sesame oil blends crystallized mainly in the β1′ polymorph state. In contrast, the 80% blend crystallized in two different polymorph states (i.e., β1′ at T≼307.6 K and β1 at T≽308.2 K). The data indicated that, in spite of the higher concentration of PS in the 80% PS/sesame oil system, crystallization in the β1 state required more free energy for nucleation (δGc) than β1′ crystallization in the 26, 42, and 60% PS/sesame oil. At the low cooling rate used (1 K/min) it was observed that, for a particular PS blend, the higher the effective supercooling the higher the viscosity of the oil phase and the smaller the induction time of crystallization (Ti). Additionally, the β1′ crystals from PS, developed at the highest effective supercooling investigated, were smaller than the β1 crystals obtained at lower effective supercooling.
Hydrogenation of soybean oil triglycerides: Effect of pressure on selectivity
Authors: List G. R. , Neff W. E. , Holliday R. L. , King J. W. , Holser R. 
Published: November 2006

AbstractSoybean oil contains five triglycerides that account for over 70% of the total. These include LLL, LLO, LLP, LOO, and LOP and their isomers (where L=linoleic, O=oleic, P=palmitic). High‐performance liquid chromatographic analysis of samples taken during a typical hydrogenation run in which the iodine value (IV) was reduced from 130 to about 70 showed that the linoleate‐containing triglycerides were reduced at a much faster rate than the linolenate‐containing triglycerides. Results clearly show that hydrogenation proceeds through definite pathways rather than by random saturation of fatty acids within the triglyceride molecules. Pressure has a significant effect on the course of hydrogenation. At higher pressures (500 psi), the reaction is truly nonselective, since di‐and trisaturated glycerides are formed at about 70 IV, whereas at 50 psi, the reaction becomes selective. At higher pressures, fat functionality and solid fat result primarily from di‐and trisaturated fatt acid triglycerides as well as trans fatty acid triglycerides. At lower pressures, functionality results from trans acid triglyceride formation. Although the reactivity of linoleate containing triglycerides followed the pattern 6 double bonds>5 double bonds>4 double bonds, other factors may be important. For example, LLP is reactive and undergoes hydrogenation, while LLS remains unchanged. Triolein, which constitutes less than 3% of the total triglyceride in natural soybean oil, is a significant product of hydrogenation, which suggests that LLL and LLO are reduced directly while adsorbed on the catalyst surface.
Simple, high‐efficiency synthesis of fatty acid methyl esters from soapstock
Authors: Haas Michael J. , Bloomer Scott , Scott Karen 
Published: November 2006

AbstractWe report a simple method that efficiently esterifies the fatty acids in soapstock, an inexpensive, lipid‐rich by‐product of edible oil production. The process involves (i) alkaline hydrolysis of all lipid‐linked fatty acid ester bonds and (ii) acid‐catalyzed esterification of the resulting fatty acid sodium salts. Step (i) completely saponified all glycerides and phosphoglycerides in the soapstock. Following water removal, the resulting free fatty acid sodium salts were rapidly and quantitatively converted to fatty acid methyl esters (FAME) by incubation with methanol and sulfuric acid at 35°C and ambient pressure. Minimum molar reactant ratios for full esterification were fatty acids/methanol/sulfuric acid of 1∶30∶5. The esterification reaction was substantially complete within 10 min and was not inhibited by residual water contents up to ca. 10% in the saponified soapstock. The product FAME contained >99% fatty acid esters, 0% triglycerides, <0.05% diglycerides, <0.1% monoglycerides, and <0.8% free fatty acids. Free fatty acid levels were further reduced by washing with dilute sodium hydroxide. Free and total glycerol were <0.01 and <0.015%, respectively. The water content was <0.04%. These values meet the current specifications for biodiesel, a renewable substitute for petroleum‐derived diesel fuel. The identities and proportions of fatty acid esters in the FAME reflected the fatty acid content of soybean lipids. Solids formed during the reaction contained 69.1% ash and 0.8% protein. Their sodium content indicated that sodium sulfate was the prime inorganic component. Carbohydrate was the predominant organic constituent of the solid.
Partially hydrolyzed rapeseed protein isolates with improved functional properties
Authors: Vioque Javier , Sánchez‐Vioque Raul , Clemente Alfonso , Pedroche Josto , Millán Francisco 
Published: November 2006

AbstractLimited rapeseed protein hydrolysates ranging from 3.1 to 7.7% hydrolysis were produced from isoelectric‐precipitated protein isolate. Water absorption, oil absorption, whippability, foam capacity and stability, emulsifying activity, and emulsion stability of the hydrolysates were determined. All protein hydrolysates showed better functional properties than the original protein isolate. Foam and emulsion stability decreased as the degree of hydrolysis increased. The hydrolysate with the lowest degree of hydrolysis showed the best functional properties. These improved functional properties make rapeseed protein hydrolysates a useful product to be used in foods such as breads, cakes, ice creams, meat products, desserts, and salad dressings.
Analysis of triacylglyceride hydroperoxides in vegetable oils by nonaqueous reversed‐phase high‐performance liquid chromatography with ultraviolet detection
Authors: Bauer‐Plank Christina , Steenhorst‐Slikkerveer Lisette 
Published: November 2006

AbstractTriacylglyceride hydroperoxides (HPO‐TAG), the primary autoxidation products of triacylglycerides (TAG), have been analyzed in polyunsaturated vegetable oils by means of nonaqueous reversed‐phase high‐performance liquid chromatography (HPLC) with ultraviolet detection. Using a retention time model based on equivalent carbon numbers, mono‐ and bishydroperoxy TAG and hydroxy TAG could be identified. The correlation between the peroxide value (POV) determined by iodometric titration and quantitative HPLC results for HPO‐TAG was established for sunflower oil samples with POV between 0.5 and 50 meq/kg. The recovery of HPO‐TAG in the HPLC procedure was found to be close to 100% in the POV range of 4 to 71 meq/kg. Absolute quantitative results for HPO‐TAG in sunflower oil samples could not be obtained accurately, as molar extinction coefficients of HPO‐TAG occurring in natural oils deviate from those of available HPO‐TAG reference compounds.
Monitoring a progressing transesterification reaction by fiber‐optic near infrared spectroscopy with correlation to 1H nuclear magnetic resonance spectroscopy
Authors: Knothe Gerhard 
Published: November 2006

AbstractBiodiesel is a promising alternative diesel fuel obtained from vegetable oils, animal fats, or waste oils by transesterifying the oil or fat with an alcohol such as methanol. In an extension of previous work, fiber‐optic near infrared spectroscopy was used to quantitatively monitor the transesterification reaction (6‐L scale) of a vegetable oil (soybean oil) to methyl soyate. The results were correlated with 1H nuclear magnetic resonance spectroscopy. The method described here can be applied to the transesterification of other vegetable oils.
Regioselective analysis of the fatty acid composition of triacylglycerols with conventional high‐performance liquid chromatography
Authors: Arcos Jose A. , Garcia Hugo S. , Hill Charles G. 
Published: November 2006

AbstractA new method for regioselective analysis of triacyglycerols via conventional high‐performance liquid chromatography (HPLC) has been developed. The method is simple and avoids the time‐consuming purification processes normally characteristics of regioselective analyses. The procedure utilizes an sn‐1,3‐specific lipase from Rhizopus arrhizus to deacylate the fatty acid residues located at the sn‐1 and sn‐3 positions of triacylglycerols. The fatty acid residues esterified at the sn‐2 position are determined by subtraction of the results of the sn‐1,3 analysis from an overall composition analysis based on complete saponification of the original sample. The fatty acid mixtures are converted to p‐bromophenacyl esters and analyzed using conventional HPLC techniques. The analytical procedure has been verified using a standard structured triacylglycerol. The analytical results for three edible vegetable oils are compared with those obtained via the method proposed by P.J. Williams and co‐workers.
Lipase‐catalyzed synthesis of ferulate esters
Authors: Compton David L. , Laszlo Joseph A. , Berhow Mark A. 
Published: November 2006

AbstractFour commercially available esterases were screened for their ability to esterify ferulic acid (4‐hydroxy‐3‐methoxy cinnamate). Novozym® 435 was found to be the only one of those screened to convert ferulic acid to ethyl and octyl ferulate at 20 and 14% yields, respectively. The highest percentage conversion was obtained using a 1∶1 mole ratio of alcohol to ferulic acid in stirred batch reactions in anhydrous 2‐methyl‐2‐propanol at 60°C using one equivalent (wt/wt based on ferulic acid) of Novozym 435. Increased water content and a higher alcohol/ethyl ferulate ratio had adverse effects on the lipase‐catalyzed esterification. The Novozym 435 activity was tested in less polar solvents (anhydrous toluene and hexane) by monitoring the alcoholysis of ethyl ferulate with 1‐octanol, which resulted in a 50% yield of octyl ferulate. The alcoholysis was improved to 83% by applying a 16 mm Hg vacuum for 5 min every 24 h to remove the ethanol co‐product. The optimal alcoholysis parameters were applied to the alcoholysis of ethyl ferulate with monoolein and the transesterification with triolein. The transesterification of ethyl ferulate with triolein in anhydrous toluene produced a combined 44% yield of ferulyl monoolein and ferulyl diolein, a 20% greater yield than that obtained for alcoholysis using monoolein. The highest yield, 77%, of ferulyl monoolein and ferulyl diolein was achieved using a threefold excess of neat triolein. The lipase‐catalyzed transesterification of ethyl ferulate with triolein appears to be a technically feasible route to ferulyl‐substituted acylglycerols, which are potentially useful sunscreen ingredients.
The study of epoxidized rapeseed oil used as a potential biodegradable lubricant
Authors: Wu Xuedong , Zhang Xingang , Yang Shengrong , Chen Haigang , Wang Dapu 
Published: November 2006

AbstractThe application of epoxidized rapeseed oil as a biodegradable lubricant is described. The epoxidation treatment has no adverse effect on the biodegradability of the base stock. Epoxidized rapeseed oil has superior oxidative stability compared to rapeseed oil based on the results of both oven tests and rotary oxygen bomb tests. Moreover, the oxidative stability can be dramatically promoted by the addition of a package of antioxidants. The epoxidized rapeseed oil has better friction‐reducing and extreme pressure abilities according to tribological investigations. Formation of a tribopolymerization film is proposed as explanation of the tribological performance of epoxidized rapeseed oil.
Physical refining of coconut oil: Effect of crude oil quality and deodorization conditions on neutral oil loss
Authors: Petrauskaitè V. , De Greyt W. F. , Kellens M. J. 
Published: November 2006

AbstractIn the present study, neutral oil loss (distillative and mechanical carry‐over) during physical refining of coconut oil was quantified. Neutral oil loss seems to depend on both the crude oil quality and the process conditions during deodorization. The distillation of volatile glyceridic components (monoand diglycerides), originally present in the crude oil, was confirmed as the major cause for the neutral oil loss. The amount of these volatile components in crude coconut oils cannot be derived as such from the initial free fatty acid content. A lower deodorization pressure with less sparge steam resulted in a larger neutral oil loss than a higher pressure with more steam. A “deodorizability” test on a laboratory scale under standardized conditions (temperature=230°C, pressure=3 mbar, time=60 min, sparge steam=1%), to evaluate crude oil quality and to obtain a more accurate prediction of the expected neutral oil loss and free fatty acid content in the fatty acid distillate, is described.