bluuebunny/crossref_metadata_2025_split huggingface dataset:
General properties and the fatty acid composition of the oil from the mophane caterpillar,Imbrasia belina
Authors: Motshegwe S. M. , Holmback J. , Yeboah S. O. 
Published: May 2007

AbstractA preliminary investigation of the bulk properties of the oil from the edible mophane caterpillar (phane),Imbrasia belina, showed a significant difference in the iodine values of the oils from mature and young phane. Detailed analysis of the fatty acid composition of the two oil samples was thus carried out by capillary gas chromatography (GC) and complemented with1H and13C nuclear magnetic resonance (NMR) studies to investigate the degree of unstauration in the two oil samples. While these studies showed that the oil samples from the mature and young mophane caterpillar were much the same in fatty acid composition, the data revealed a significant divergence from a literature report on phane oil. This earlier report puts the ratio of total saturated to total unsaturated fatty acids at approximately 1:1 (48.2:48.8, in percentages) and estimates the fatty acid composition for the major fatty acids as 16:0 (31.9%), 18:0 (15.2%), 18:1 (20.4%), 18:2 (9.9%), and 18:3 (19%). The data collected from the present work, however, showed the fatty acid composition for total saturated and total unsaturated fatty acids to be 40.5 and 57.0%, respectively. This work estimated the fatty acid composition for the major fatty acids as 16:0 (27.2%), 18:0 (12.3%), 18:1 (16.1%), 18.2 (10.7%), and 18:3 (29.0%). Thus, linolenic acid was the most abundant fatty acid in the phane oil. The GC results of the present analysis were largely corroborated by studies of the composition of fatty acid classes in the phane oil estimated from integrals of1H and13C NMR signals. Oils from other edible Lepidoptera larvae are also known to be much richer in unsaturated than saturated fatty acids.
Effect of xanthan gum on enhancing the foaming properties of soy protein isolate
Authors: Xie Y. R. , Hettiarachchy N. S. 
Published: May 2007

AbstractThe foaming properties of soy protein isolate (SPI) in the presence of xanthan gum (XG) were investigated. The XG solution alone did not exhibit any foaming ability. The optimal foaming properties were obtained from the SPI‐XG dispersion that contained 0.1% SPI and 0.2% XG. This SPI‐XG dispersion gave higher foaming capacity than that of SPI or egg white (P<0.05). The foam stability of SPI‐XG dispersion was nine times higher than that of SPI and egg white (P<0.05). The SPI‐XG foams were stable over wide ranges of ionic strength (0.1 to 1.0 M NaCl) and pH (4.5 to 9.0), and when heated (85°C, 1 h).
Concentration and stabilization of n‐3 polyunsaturated fatty acids from sardine oil
Authors: Ganga Angélica , Nieto Susana , Sanhuez Julio , Romo Claudio , Speisky Hernán , Valenzuela Alfonso 
Published: May 2007

AbstractA simple and relatively inexpensive procedure to obtain 90% eicosapentaenoic acid + docosahexaenoic acid concentrates from sardine oil involved a two‐step winterization of the oil (10 and 4°C), followed by saponification and selective precipitation of saturated and less unsaturated free fatty acids by an ethanolic solution of urea. Antioxidant effects of butylated hydroxytoluene, dl‐α‐tocopherol, and two natural antioxidants, quercetin and boldine, added to the concentrate (0.5% wt/vol), were compared in the Rancimat at 60°C. dl‐α‐Tocopherol was unable to inhibit concentrate oxidation. Butylated hydroxyanisole and butylated hydroxytoluene had induction periods of 1.7–1.8 h compared to the control (1.0 h). A mixture of quercetin + boldine (2:1 w/w) significantly increased the induction period to 4.5 h.
Quality and compositional studies of some edible leguminosae seed oils in Botswana
Authors: Ketshajwang K. K. , Holmback J. , Yeboah S. O. 
Published: May 2007

AbstractSeed oils were extracted with n‐hexane from three edible Leguminosae seeds: Tylosema esculentum, Xanthocercis zambesiaca, and Bauhinia petersiana, giving yields of 48.2, 17.6, and 20.8% (w/w), respectively. Some physical and chemical parameters were determined to ascertain the general characteristics of the oils. The saponification and iodine values indicated that all three oil samples could be classified among the olive group of oils. This inference was supported by the results of the detailed fatty acid composition of the oils as determined by capillary gas chromatography. The ratio of total unsaturated to total saturated fatty acids in all three oil samples was approximately 70:30, with either oleic or linoleic acid being the dominant fatty acid. These results were in agreement with a proton nuclear magnetic resonance analysis of the fatty acid classes in the seed oils. Thus, the analysis served to justify the use of the three Leguminosae seed oils in food preparations. The work has further indicated that, with their attractive properties, the seed oils from T. esculentum, X. zambesiaca, and B. petersiana are good candidates for further studies to evaluate their future commercial prospects in the Southern African region.
Preparation of monoglycerides by guanidine‐catalyzed processes
Authors: Aguiar Leila M. Guimarães , Vargas Rogério Matheus 
Published: May 2007

AbstractGlycerolysis of methyl stearate and tristearin has been carried out in the presence of alkylguanidines—strong nonionic bases—as catalysts. When applied at 10 mol%, 1,5,7‐triazabicyclo [4.4.0]dec‐5‐ene, 1,2,3‐tricyclohexylguanidine, and 1,3‐dicyclohexyl‐2‐n‐octylguanidine give monoglycerides in more than 90% selectivity, in a maximum of 6 h reaction time.
Properties of rapeseed oil for use as a diesel fuel extender
Authors: McDonnell K. , Ward S. , Leahy J. J. , McNulty P. 
Published: May 2007

AbstractChemical and thermal analyses were carried out on degummed and filtered (5 µm) rapeseed oil (referred to as SRO, i.e., semirefined rapeseed oil) to determine its suitability as a diesel fuel extender. The upper rate for inclusion of SRO with diesel fuel is 25%. This fuel blend had a phosphorus level of 2.5 ppm, which was comparable to rape methyl esters (1.0 ppm phosphorus). Thermogravimetric analyses were used to estimate the cetane ratings of the fuels. A 25% SRO/diesel blend had an estimated cetane index of 32.4 compared to 38.1 for diesel fuel only. Differential scanning calorimetry and thermogravimetric analyses were used to compare the volatility ranges of the fuels. SRO needed higher temperatures for volatilization (i.e., 70–260°C for diesel fuel vs. 280–520°C for SRO). This indicated poorer cold‐starting performance of SRO compared with diesel fuel. SRO fuel is a low‐sulfur, high‐oxygen fuel giving SRO a more favorable emissions profile than pure diesel fuel.
Transesterification of heated rapeseed oil for extending diesel fuel
Authors: Mittelbach M. , Enzelsberger H. 
Published: May 2007

AbstractFatty acid methyl esters are well established as an alternative fuel called “biodiesel.” For economic reasons, used frying oil is an interesting alternative feedstock for biodiesel production. The chemical changes that occur during heating of rapeseed oil, especially the formation of polymers, were investigated. Heated rapeseed oil samples were transesterified with methanol and analyzed by size‐exclusion chromatography. During heating, the amount of polymers in the starting oil increased up to 15 wt%, but only up to 5 wt% in the transesterified samples. So during transesterification, dimeric and trimeric triglycerides in the starting oil were mainly converted into monomeric and dimeric fatty acid methyl esters. The amount of polymeric fatty acid methyl esters had a negative influence on fuel characteristics. After 6 h of heating, the amount of Conradson carbon residue and after 16 h the viscosity exceeded that of the existing specifications for biodiesel. Therefore, the amount of polymers in waste oil is a good indicator for the suitability for biodiesel production.
Preparation of fatty epoxy alcohols using oat seed peroxygenase in nonaqueous media
Authors: Piazza George J. , Foglia Thomas A. , NuɁez Alberto 
Published: May 2007

AbstractPeroxygenase is an enzyme of higher plants that is capable of using hydroperoxide and hydrogen peroxide for oxidation of a double bond to an epoxide. A microsomal fraction was prepared from dry oat (Avena sativa) seeds. The peroxygenase activity of this fraction was tested using fatty acid hydroperoxide 2a [13(S)‐hydroperoxy‐9(Z), 11(E)‐octadecadienoic acid] and its methyl ester 2b as sources of peroxygen. These were prepared by the action of soybean lipoxygenase on linoleic acid. A high‐performance liquid chromatographic assay was used to differentiate between peroxygen cleavage and peroxygen cleavage with accompanying double‐bond oxidation Higher activity was obtained with 2b compared to 2a, and peroxygen cleavage activity was observed in both aqueous and organic solvent media. Double‐bond oxidation activity was high only in aqueous media and nonpolar organic solvents. Structural elucidation of the epoxidized product showed it to be the oxylipid, methyl cis‐9,10‐epoxy‐13(S)‐hydroxy‐11(E)‐octade‐cenoate 4b, demonstrating specificity for epoxidation of the cis double bond. Trihydroxy product was not detected, demonstrating that the epoxide was not hydrolyzed.
Borago officinalis oil: Fatty acid fractionation by immobilized Candida rugosa lipase
Authors: Schmitt‐Rozieres Murielle , Vanot Guillaume , Deyris Valérie , Comeau Louis‐Claude 
Published: May 2007

Abstractγ‐Linolenic acid (Z,Z,Z‐6,9,12‐octadecatrienoic acid), a very important polyunsaturated fatty acid is found in the free fatty acid fraction prepared by the hydrolysis of borage oil. Our aim was to enrich this fraction in γ‐linolenic acid using selective esterification. Candida rugosa lipase was used as catalyst after immobilization on the following ion‐exchange resins: Amberlite IRC50, IRA35, IRA93, and Duolite A7, A368, A568. In every case, immobilization modified the lipae's specificity: palmitic, stearic, oleic, and linoleic acids were preferentially esterified compared to γ‐linolenic acid, thus allowing a γ‐linolenic acid enrichment of 3.0.
Enzymatic synthesis of structured lipids from single cell oil of high docosahexaenoic acid content
Authors: Iwasaki Yugo , Han Jeong Jun , Narita Miho , Rosu Roxana , Yamane Tsuneo 
Published: May 2007

AbstractThe lipase‐catalyzed acidolysis of a single‐cell oil (SCO) containing docosahexaenoic acid (DHA) and docosapentaenoic acid (DPA) with caprylic acid (CA) was investigated. The targeted products were structured lipids containing CA residues at the sn‐1 and ‐3 positions and a DHA or DPA residue at the sn‐2 position of glycerol. Rhizomucor miehei lipase (RML) and Pseudomonas sp. KWI‐56 lipase (PSL) were used as the biocatalysts. When PSL was used > 60 mol% of total SCO fatty acids (FA) were exchanged with CA, with DHA and DPA as well as the other saturated FA being exchanged. The content of the triacylglycerols (TG) containing two CA and one DHA or DPA (number of carbon atoms = 41, i.e., C41) residue was high (36%), and the isomer with the desired configuration (unsaturated FA residue at the sn‐2 position) represented 77–78% of C41. In the case of RML, CA content reached only 23 mol% in the TG. A large amount of DHA and DPA residues remained unexchanged with RML, so that the resulting oil was rich in TG species containing two or three DHA or DPA residues (46%). TG C41 amounted to 22%, almost all of which had the desired configuration. This result suggested that the difference in the degree of acidolysis by the two enzymes was due to their different selectivity toward DHA and DPA, as well as the difference in their positional specificities.
Immobilization of lipase on poly(N‐vinyl‐2‐pyrrolidone‐co‐2‐hydroxyethyl methacrylate) hydrogel for the synthesis of butyl oleate
Authors: Basri M. , Wong C. C. , Ahmad M. B. , Razak C. N. A. , Salleh A. B. 
Published: May 2007

AbstractLipase from Candida rugosa was immobilized by entrapment on poly(N‐vinyl‐2‐pyrrolidone‐co‐2‐hydroxyethyl methacrylate) [poly(VP‐co‐HEMA)] hydrogel, cross‐linked with ethylene glycol dimethacrylate (EDMA). The immobilized enzyme was used in the esterification of oleic acid with butanol in hexane. The activities of the immobilized enzyme preparations and the leaching of the enzyme from the hydrogel supports with respect to composition were investigated. The thermal, solvent, and storage stability of the immobilized preparations also were determined. Increasing the percentage VP from 0 to 90, which corresponds to the increase in the hydrophilicity of the hydrogels, increased the activity of the immobilized enzyme. Lipase immobilized onto VP(%):HEMA(%), 90:10 hydrogel had the highest activity. Increasing the hydrophobicity of the hydrogel (increasing the percentage HEMA) seemed to decrease leaching of the enzyme from the support. Immobilized lipase on 100% HEMA hydrogel indicated highest entrapment and lowest leaching by hexane washing. The lipase immobilized on VP(%):HEMA(%), 50:50 hydrogel showed highest thermal, solvent, and storage stability compared to lipase immobilized on other hydrogel compositions as well as the native lipase.
Milk fat fractionation by solid‐layer melt crystallization
Authors: Peters‐Erjawetz Sandra , Ulrich Joachim , Tiedtke Michaela , Hartel Richard W. 
Published: May 2007

AbstractThe layer crystallization process has the potential to produce the same milk fat fractions as can be obtained by the suspension crystallization process. That is, milk fat fractions with solid fat content melting profiles similar to those obtained by suspension fractionation can be produced with this technique. The fatty acid profiles as well as the melting enthalpies of the different fractions confirm the separation of milk fat by the layer technique. Furthermore, there is potential to improve the results of separation presented in the first part of this paper. The two sources of improvement, temperature control of the process and controlled nucleation, lead to (i) a smooth crystalline layer with a low amount of entrapped mother liquor, contrary to the layers composed of agglomerated needles, and (ii) a good quality of attachment of the crystalline layer to the cooled surface. Moreover, the product quality can be increased using sweating as a postcrystallization step. “Sweating by warm gas” seems to have a better outlook concerning handling and controlling the process than “sweating by warm tube” because sloughing of the crystal layers can be avoided. Further investigations of the mass ratio of sweating fraction and amount of product as well as the aspect of energy consumption will determine the technical feasibility of solid‐layer crystallization for fractionation of milk fat.
Crystallization and pressure filtration of anhydrous milk fat: Mixing effects
Authors: Patience D. B. , Hartel R. W. , Illingworth D. 
Published: May 2007

AbstractMelt crystallization of anhydrous milk fat and subsequent filtration of the slurry is a common process for obtaining milk fat fractions with different physical and chemical properties. The crystallization mechanism is very complex and little is known about how the crystallizer conditions and the crystal size distribution (CSD) affect the filtration process. The objective of this study was to characterize the fractionation process and determine which geometric parameters of the crystallizer affect the filtration step. Two scales of fractionation were studied, 0.6 L and 3.6 L, with crystallization at 28°C. The slurry was pressure‐filtered after 24 h at 500 kPa in a 1‐L chamber. Impeller diameters and speeds were varied for both scales. Photomicroscopy and spectrophotometry were used to characterize the crystallization process, and filtration rates were measured by weighing the amount of filtrate passing through the filter. Filtration resistance values, calculated using the constant pressure filtration equation, as well as photomicroscopy results indicated that the agglomerates and crystals that formed had different morphological characteristics for the different mixing and flow regimes in the crystallizer. Crystallization conditions that provide an optimal filtration time, a solid fraction with minimal liquid entrainment, and a CSD with an intermediate range of sizes (80–500 µm) having good packing properties for filtration were found.
Crystal packing of a homologous series β′‐stable triacylglycerols
Authors: van Langevelde Arjen , van Malssen Kees , Sonneveld Ed , Peschar René , Schenk Henk 
Published: May 2007

AbstractFrom a homologous series of CnCn+2Cn (n = even) triacylglycerols which are β′‐stable, Guinier X‐ray powder diffraction photographs were used to determine cell parameters and space groups. The powder diffraction patterns are consistent with a pseudo‐orthorhombic unit cell with space group lc2a. Only one axis is changing as a function of chain lengthening. The experimental results were used to propose a β′‐crystal packing for triacylglycerols. In contrast to earlier proposed β′‐crystal structures, the acyl chains of this structure are not tilted with respect to the methyl‐end group plane. Furthermore, with only one molecule in the asymmetric unit, overall orthogonal chain packing is obtained when the intramolecular acyl zigzag planes are parallel.
Determination of olive oil free fatty acid by fourier transform infrared spectroscopy
Authors: Bertran Enriqueta , Blanco Marcelo , Coello Jordi , Iturriaga Hortensia , Maspoch Santiago , Montoliu Ivan 
Published: May 2007

AbstractA new procedure for determining free fatty acids (FFA) in olive oil based on spectroscopic Fourier transform infrared‐attenuated total reflectance spectroscopy measurements is proposed. The range of FFA contents of samples was extended by adding oleic acid to several virgin and pure olive oils, from 0.1 to 2.1%. Calibration models were constructed using partial least‐squares regression (PLSR). Two wavenumber ranges (1775–1689 cm−1 and 1480–1050 cm−1) and several pretreatments [first and second derivative; standard normal variate (SNV)] were tested. To obtain good results, splitting of the calibration range into two concentration intervals (0.1 to 0.5% and 0.5 to 2.1%) was needed. The use of SNV as a pretreatment allows one to analyze samples of different origins. The best results were those obtained in the 1775–1689 cm−1 range, using 3 PLSR components. In both concentration ranges, at a confidence interval of α = 0.05, no significant differences between the reference values and the calculated values were observed. Reliability of the calibration vs. stressed oil samples was tested, obtaining satisfactory results. The developed method was rapid, with a total analysis time of 5 min; it is environment‐friendly, and it is applicable to samples of different categories (extra virgin, virgin, pure, and pomace oil).
Influence of ecological cultivation on virgin olive oil quality
Authors: Gutiérrez Francisca , Arnaud Teresa , Albi Miguel A. 
Published: May 2007

AbstractThe quality of oil extracted from ecologically cultivated olives of the Picual variety was compared with oil extracted from Picual olives cultivated using conventional methods. Olive trees were grown in a two‐section plot. Fruits from each plot were harvested at various stages of ripeness, and acidity value, peroxide index, ultraviolet absorption at 232 and 270 nm, stability to oxidation, sensory analysis, fatty composition, and contents of tocopherols, phenolic compounds, and sterols were determined on oil extracted from each treatment. The results showed that the organic virgin olive oil was of a superior quality to the conventional virgin olive oil in all the quality parameters analyzed.
Classification of virgin olive oils of the two major cretan cultivars based on their fatty acid composition
Authors: Stefanoudaki E. , Kotsifaki F. , Koutsaftakis A. 
Published: May 2007

AbstractFatty acid composition was determined for 105 virgin olive oil samples of the two dominant Cretan olive cultivars, Koroneiki and Mastoides, harvested from different producing areas at different maturity stages. The oils of the Koroneiki cultivar were characterized by lower concentrations of oleic and decaheptanoic and higher concentrations of linoleic and palmitic acids. Oils obtained from high‐altitude locations were rich in monounsaturated fatty acids, while oils obtained from low‐altitude locations had higher content of saturated fatty acids. Palmitic and palmitoleic acids increased with increasing altitude in both cultivars examined. The statistical analysis of the compositional data showed significant potential for the classification of the samples according to cultivar and location of origin.
Frying performance of genetically modified canola oils
Authors: Petukhov I. , Malcolmson L. J. , Przybylski R. , Armstrong L. 
Published: May 2007

AbstractThe frying performance of low linolenic and high oleic canola oils was compared to regular and hydrogenated canola oils. The antifoaming agent dimethylpolysiloxane (2 ppm) was added to all frying oils. Potato chips were fried in the four oils over a 5‐d period for a total of 40 h of frying. Oil samples were collected each day and analyzed for conjugated dienoic acids, free fatty acids, polymers, oxidation products, and polar components. Polar components were determined by the gravimetric method and by thin‐layer chromatography with flame‐ionization detection. The initial quality of the four oils was similar except in the amount of tocopherols present. All oils deteriorated after 5 d of frying but differences were not as anticipated, possibly as a result of observed differences in tocopherol levels.
Antioxidant effect of the constituents of susabinori (Porphyra yezoensis)
Authors: Nakayama Reiko , Tamura Yoshiyuki , Kikuzaki Hiroe , Nakatani Nobuji 
Published: May 2007

AbstractThe antioxidant activities of several extracts from Susabinori (Porphyra yezoensis) were measured by the ferric thiocyanate method and the thiobarbituric acid method. The methanol, acetone, ethyl acetate, and hexane extracts, and the chloroform‐soluble and water‐soluble fractions from the chloroform‐methanol extract exhibited higher activities than α‐tocopherol. The hot water extract showed little activity. Thin‐layer chromatography analysis of the active extracts suggested the existence of several antioxidants. The activity of the chloroform soluble fraction was due to chlorophyll analogs. A strong antioxidant was isolated from the methanol extract, accompanied by several amino acids such as leucine and phenylalanine. This compound was identified as usujilene, a kind of mycosporine‐glycine like amino acid.
Recent advances in assessment of marine lipid oxidation by using fluorescence
Authors: Aubourg Santiago P. 
Published: May 2007

AbstractLipid changes during food processing are important because of their impact on the final product quality. Lipid damage detection is limited because of the ability of lipid oxidation products (i.e., hydroperoxides and carbonyl compounds) to produce interaction compounds by reacting with nucleophilic food constituents. Fluorescence quantification at a single excitation/emission maximum of these interaction compounds has been employed in a qualitative way as a complementary tool for food quality assessment. The present work reviews recent research where simultaneous detection at different excitation/emission maxima was employed to assess lipid oxidation and quality changes during fish processing. A fluorescence shift towards a higher wavelength maxima was detected as a result of lipid damage; the shift was calculated as the ratio (δF) between two of the maxima tested (393/463 nm and 327/415 nm) and was investigated along different fish processes (freezing and frozen storage, refrigerated storage, cooking, and canning) and in complementary model systems where the influence of different factors (time and temperature of processing, amine and aldehyde composition and content, formaldehyde presence, and pH value of the medium) was checked. Determination of the δF value provided better results for quality change assessment in fish products than most of the lipid quality indices, in addition to being rapid and sensitive.