bluuebunny/crossref_metadata_2025_split huggingface dataset:
Unusual predominance of even‐carbon hydrocarbons in an antarctic food chain
Authors: Nachman Ronald J. 
Published: November 2006

AbstractA comparative study of lipids was conducted inEuphausia crystallorophias, Pleuragramma antarcticum andDissostichus mawsoni, representing three trophic levels of an Antarctic food chain. Very large concentrations of triglycerides were found inP. antarcticum andD. mawsoni, but the nature of the free fatty acids and triglyceride fatty acid distributions of all three species was unremarkable. The larger amounts of free fatty acids obtained inEuphausia crystallorophias, when compared to a previous analysis, may have been due to enzymatic hydrolyses of lipid esters during cold storage. In contrast, the hydrocarbon distributions in the three organisms were found to contain an unusual predominance of even‐carbonn‐alkane constituents. A different biochemical pathway to hydrocarbons may be operating in members of this food chain that is so well adapted to the low temperatures of Antarctic waters.
The effects of ethanol content and emulsifying agent concentration on the stability of vegetable oil‐ethanol emulsions
Authors: Xu Qingyi , Nakajima Mitsutoshi , Nabetani Hiroshi , Iwamoto Satoshi , Liu Xinqi 
Published: November 2006

AbstractIn vegetable oil‐ethanol emulsions ethanol is the polar phase and vegetable oil is the nonpolar phase. The primary advantage of vegetable oil‐ethanol emulsions over conventional water‐oil emulsions is that they enable the incorporation of water‐and oil‐insoluble or poorly soluble functional compounds and/or drugs into emulsions. A number of nonionic surfactants were used to select appropriate stabilizers for stable vegetable oil‐ethanol emulsions. We found decaglycerol mono‐oleate (MO750) to be the best stabilizer for ethanol‐in‐oil (E/O) emulsions. The effects of ethanol content and of emulsifying agent concentration on the stability of vegetable oil‐ethanol emulsions were examined with MO750. After emulsification, two turbid layers formed simultaneously when ethanol content exceeded 20 wt%. The top layers (oil‐in‐ethanol emulsions; O/E emulsions) were very unstable, whereas the stability of the bottom layers (E/O emulsions) depended on the ethanol content. The stability of E/O emulsions is closely related to the effective concentration of MO750 aggregates, which play an important role in the film thickness stability of interfacial films formed by surfactant aggregates. Instability of E/O emulsion at 5 wt% MO750 is probably due to the polydispersity (i.e., nonuniform size and shape) of MO750 aggregates at high MO750 concentration. E/O emulsions prepared with 0.1, 0.5, and 1 wt% MO750 were stable, suggesting that the interfacial films formed were effective in protecting the droplets against coalescence and Ostwald ripening.
Comparison of lipase‐transesterified blend with some commercial solid frying shortenings in Malaysia
Authors: Chu B. S. , Ghazali H. M. , Lai O. M. , Che Man Y. B. , Yusof S. , Tee S. B. , Yusoff M. S. A. 
Published: November 2006

AbstractA transesterified experimental solid frying shortening was prepared from a palm stearin/palm kernel olein blend at 1∶1 ratio (by weight) by using Rhizomucor miehei lipase at 60°C for 6 h. The fatty acid (FA) and triacylglycerol compositions, polymorphic forms, melting and cooling characteristics, slip melting point (SMP), and solid fat content (SFC) of the transesterified blend were then compared with five commercial solid frying shortenings (three domestic and two imported) found in Malaysia. All the domestic shortenings contained nonhydrogenated palm oil or palm olein and palm stearin as the hard stock, whereas the imported frying shortenings were formulated from soybean oil and cottonseed oil and contained high level of β′ crystals. Trans FA were also found in these samples. The lipase‐transesterified blend was found to be more β′‐tending than the domestic samples. The SMP of the transesterified blend (47.0°C) fell within the range of the domestic samples (37.8–49.7°C) but was higher than the imported ones (42.3–43.0°C). All samples exhibited similar differential scanning calorimetry cooling profiles, with a narrow peak at the higher temperatures and a broad peak at the lower temperatures, even though their heating thermograms were quite different. Imported samples had flatter SFC curves than both the experimental and domestic samples. The domestic samples were found to have better workability or plasticity at higher temperatures than the imported ones, probably because they were formulated for a tropical climate.
Definition of a model fat for crystallization‐in‐emulsion studies
Authors: Lopez C. , Riaublanc A. , Lesieur P. , Bourgaux C. , Keller G. , Ollivon M. 
Published: November 2006

AbstractNumerous food products are dispersed in droplet emulsions in which fat is partially crystallized. A model fat allowing the study of crystallization in emulsion, obtained by the mixing of two fats (one solid and one liquid at room temperature) with simple triacylglycerol (TG) composition, is defined and characterized. Cocoa butter (CB), a vegetable fat mainly composed of monounsaturated long‐chain fatty acids (POP, POST, StOSt, where P=palmitic, O=oleic, St=stearic), and miglyol, a synthetic oil made from capric and caprylic fatty acids, were chosen, respectively. The thermal behaviors of CB, miglyol, and their mixtures are studied using high‐sensitivity differential scanning calorimetry (DSC). The CB/miglyol ratio was optimized (i) in order to make stable emulsions as a function of time, (ii) so that the mixture displays several solid phases on cooling that result from CB polymorphism, and (iii) in order to keep, even at low temperature, a liquid moiety facilitating the phase transitions. The CB 75%/miglyol 25% composition is defined as the model mixture. This mixture is characterized on cooling at 0.5°C/min by coupled X‐ray diffraction as a function of temperature and DSC experiments. First and α 2L (49.3 Å) variety is formed. Then, co‐crystallization of both CB and miglyol TG shows the simultaneous formation of longitudinal stackings of 44.5 and 34.5 Å with a lateral organization of β′ form. An unusual TG packing corresponding to compound formation is proposed to explain the observation of a 34.5 Å long‐spacing. The crystallization behavior of the model fat mixture dispersed in emulsion droplets is also monitored in order to validate its use.
Photometric assay for polyphenol oxidase activity in olives, olive pastes, and virgin olive oils
Authors: Valgimigli Luca , Sanjust Enrico , Curreli Nicoletta , Rinaldi Augusto , Pedulli Gian F. , Rescigno Antonio 
Published: November 2006

AbstractA photometric method is proposed that allows the determination of phenolase activity in olive fruits, olive pastes, and virgin olive oil. The method can also be used to quantify partially purified phenolase from olives, and is based on the coupling between 4‐methyl‐o‐benzoquinone, the reaction product of phenolase toward its substrate 4‐methylcatechol, and the aromatic amine 4‐amino‐N,N‐diethylaniline. The deep‐blue adduct arising from this reaction has been characterized by means of nuclear magnetic resonance and mass spectrometric techniques and identified as 4‐(4′‐diethylaminophenylimino)‐2‐hydroxy‐5‐methyl‐cyclohexa‐2,5‐dienone. This compound shows an absorption band, centered (in dichloromethane) at 617 nm, with an ε of 11,080 M−1cm−1. The main advantage of the proposed method resides in the high absorption coefficient of the adduct and its ultraviolet/visible absorption pattern, with a λmax in a spectral region void of significant interferences by the pigments that ultimately will probably be present in the extracts to be tested by this proposed method. The method has proven to be sensitive, specific, and reliable.
Off‐line coupling of high‐performance liquid chromatography and 1H nuclear magnetic resonance for the identification of filbertone in hazelnut oil
Authors: Ruiz del Castillo M. L. , Herraiz M. , Molero M. D. , Herrera A. 
Published: November 2006

AbstractA new procedure is presented for off‐line coupling of high‐performance liquid chromatography and proton nuclear magnetic resonance spectroscopy (1H NMR) in hazelnut oil analysis. The optimization of some parameters affecting both the liquid chromatography preseparation step and the effective multiple‐solvent suppression required for the NMR study enabled us to determine the presence in a hazelnut oil of (E)‐5‐methyl‐hept‐2‐en‐4‐one (filbertone), a marker previously proposed to detect the adulteration of olive oil with hazelnut oil. The described procedure requires the filtration of the oil prior to its introduction into the chromatographic system and combines the advantages of providing sufficient sensitivity and selectivity with simple methodology and reduced sample handling.
Free fatty acid formation and lipid oxidation on milled rice
Authors: Lam Henry S. , Proctor Andrew , Meullenet Jean‐François 
Published: November 2006

AbstractMilled rice was stored at 37°C and 70% humidity and sampled regularly for 50 d. Rice surface lipid was extracted with isopropanol and analyzed for free fatty acids (FFA) and conjugated diene (CD) contents. Diffuse reflectance Fourier transform infrared (DRIFTS) spectra of the rice samples were also obtained. FFA and CD levels increased together during rice storage and exhibited three distinct phases. DRIFTS identified a decrease in intensity at 1746 cm−1 (ester, −C=O) and increases in intensity at 1731 cm−1 (aldehyde, −CO) and 1714 cm−1 (fatty acid, −C=O) during storage, which correlated well with the chemical analysis data. DRIFTS spectral data were analyzed by a partial least squares regression method to identify spectral regions that correlate strongly with measured FFA and construct prediction models. Overall, the mid‐infrared region (4000–400 cm1) gave the best model (R=0.98, root mean square error of cross‐validation=0.05) and also predcted the FFA content of milled rice well. The DRIFTS technique has potential for use in studying qualitative chemical changes on the milled rice surface lipids and for predicting FFA on milled rice.
Hepatic lipid characteristics and histopathology of laying hens fed CLA or n−3 fatty acids
Authors: Cherian Gita , Goeger Mary P. 
Published: November 2006

AbstractThe effect of dietary CLA and n−3 PUFA on hepatic TAG accumulation, histopathology, and FA incorporation in lipid classes by laying chickens was investigated. One hundred twenty 30‐wk‐old single‐comb white leghorn laying hens were distributed randomly to four treatments (3 replications of 10 birds) and were fed diets containing CLA and animal fat (Diet I), 18∶3n−3 (Diet II), or long‐chain n−3 FA (Diet III). A sunflower oil (n−6 FA)‐based diet was the control. Feeding Diet I resulted in an increase in hepatic total lipids (P<0.05). The liver TAG content was 32.2, 18.9, 29.4, and 18.7 mg/g for hens fed Diet I, Diet II, Diet III, and the control diet, respectively (P<0.05). The serum TAG was lowest in bilds fed Diet II (P<0.05). Diet I resulted in an increase in the total number of fat vacuoles and lipid infiltration in hepatocytes (P<0.05). The number of cells with 75% or higher lipid vacuolation was observed only in birds fed Diet I. Feeding diets containing CLA resulted in an increase in the content of the c9,t11 CLA isomer in liver TAG and PC (P<0.05). No difference was observed in the CLA concentration of hepatic PE fractions. The content of DHA (22∶6n−3) was higher in the TAG, PC, and PE of hens fed Diet II and Diet III than Diet I and the control (P<0.05). Feeding CLA resulted in an increase in total saturated FA in the TAG and PC fractions (P<0.05). Long‐term feeding of CLA in laying birds leads to an increase in liver TAG and may predispose birds to fatty liver hemorrhagic syndrome.
Alterations of fatty acid metabolism and membrane fluidity in peroxisome‐defective mutant ZP102 cells
Authors: Nagura Michiaki , Saito Makiko , Iwamori Masao , Sakakihara Yoichi , Igarashi Takashi 
Published: November 2006

AbstractWe investigated lipid composition and FA metabolism in Chinese hamster ovary (CHO‐K1) cells and Pex5‐mutated CHO‐K1 (ZP102) cells to clarify the biochemical bases of peroxisome biogenesis disorders (PBD). ZP102 cells have defective peroxisomes and exhibit impairments of peroxisomal β‐oxidation of FA and plasmalogen biosynthesis. In addition, we identified FA metabolic alterations in the synthesis of several classes of lipids in ZP102 cells. The concentration of FFA in ZP102 cells was twice that in CHO‐K1 cells, but methyl esters and TAG were decreased in ZP102 cells in comparison with control cells. Also, ceramide monohexoside (CMH) concentration with ZP102 cells was significantly increased compared with the control cells. The FA molecular species, particularly the saturated to unsaturated ratios, of individual lipids also differed between the two cell types. The rate of incorporation of [14C]‐labeled saturated acids into sphingomyelin (SM) and CMH in ZP102 cells was lugher than that in CHO‐K1 cells. Lignoceric acid incorporated into cells was predominantly utilized for the synthesis of SM at 24 h after removal of [14C] lignoceric acid from the culture medium. ZP102 cells showed higher fluorescence anisotropy of 1,3,5‐diphenylhexatriene, corresponding to lower membrane mobility than in CHO‐K1 cells. In particular, alteration of lipid metabolism by a Pex5 mutation enhanced metabolism of saturated FA and sphingolipids. This may be related to the reduced membrane fluidity of ZP102 cells, which has been implicated in the dysfunction of membrane‐linked processes in PBD.
Fatty acids of serine, ethanolamine, and choline plasmalogens in some marine bivalves
Authors: Kraffe Edouard , Soudant Philippe , Marty Yanic 
Published: November 2006

AbstractThe FA composition of glycerophospholipid (GPL) classes and subclasses was investigated in whole animals of three marine bivalve mollusks: the Japanese oyster Crassostrea gigas, the blue mussel Mytilus edulis, and the Manila clam Ruditapes philippinarum. Individual organs (gills, mantle, foot, siphon, and muscle) of the Manila clam also were examined. The PS plasmalogen (PSplsm), PE plasmalogen (PEplsm), and PC plasmalogen (PCplsm) subclasses were isolated by HPLC, and their individual FA compositions were examined using GC. Plasmalogen forms of PS and PE, when compared to their respective diacyl forms, were found to be specifically enriched with non‐methylene‐interrupted (NMI) FA (7,15–22∶2, 7, 13–22∶2, and their precursors) and 20∶1n−11 FA. Such a clear specific association was not found for PCplsm. Interestingly, this trend was most apparent in PSplsm, and the above FA were found to be, respectively, the predominant PUFA and monounsaturated FA in the PSplsm isolated from the three species. This specificity was maintained in all the analyzed organs of the Manila clam but varied in proportions: The highest level of plasmalogens, NMI FA, and 20∶1n−11 was measured in gills and the lowest was in muscle. These results represent the first comprehensive report on a FA composition of the PSplsm subclass isolated from mollusks. The fact that NMI FA and 20∶1n−11, which are thought to be biosynthesized FA, were mainly associated with aminophospholipid plasmalogens (PE and PS) is likely to have a functional significance in bivalve membranes.
Steam‐explosion pretreatment of olive cake
Authors: Felizón B. , Fernández‐Bolaños J. , Heredia A. , Guillén R. 
Published: November 2006

AbstractOlive cake was processed by steam‐explosion under different steam conditions, followed by fractionation to separate the main components. In the water‐soluble fraction, the main compounds were carbohydrates. Glucose represented a significant part of the total monosaccharide content, especially under conditions of mild severity, followed by arabinose, but the solubilization of sugars occurred predominantly in the oligomeric fraction. Mannitol was also found in significant amounts (1.5%), similar to that in the initial material. In the ethyl acetate extract, low molecular weight phenols were identified, the most aboundant being hydroxytyrosol, which is present in the olive pulp. Hydroxytyrosol is abundant and has great antioxidant activity, reaching 149 mg/100 g of dry olive cake. The procedure used in this study obtained all the hydroxytyrosol residual present in the by‐product. The constitutive polymers were quantified in the insoluble fraction, and the sugar composition showed that cellulose was associated with a high proportion of xylans and other polysaccharides rich in arabinose and galactose. This cellulose was nearly amorphous, as it was highly susceptible to hydrolytic enzymes. The extractables in dilute alkali (not true lignins) increased as steaming became more severe; the residual “lignin” in this fraction decreased. Enzymatic hydrolysis of the insoluble fraction using a cellulolytic complex was also studied. The slight increase in the extent of saccharification was not proportional to the high alkaline delignification. However, when the residues were efficiently delignified with chlorite treatment, the susceptibility to enzymatic hydrolysis greatly increased.
Rheological study of dispersions prepared with modified soybean protein isolates
Authors: Puppo M. C. , Sorgentini D. A. , Añón M. C. 
Published: November 2006

AbstractStructural modifications of modified soy protein isolates (SPI) were distinguished by rheological behavior. SPI were prepared by acidic (pH 2.5) and thermal‐acidic treatment without (pH 1.6) and with neutralization (pH 8.0). Dynamic properties of dispersions were determined through the variation of storage and loss moduli with frequency, and loss tangent behavior was analyzed. Changes in viscoelastic parameters with protein concentration (10–12% wt/vol) and time of heating (15–60 min) were also determined. Flow properties of dispersions were estimated through apparent viscosity and flow and consistency index measurements. Rheological behavior of dispersions was compared with those found by experiment with commercial mayonnaise, mustard, and salad dressing. The analysis of rheological parameters showed that thermally treated isolates formed dispersions with high elastic modulus and consistency index with a structure mainly stabilized by hydrophobic interactions, although no gelation process after cooling was observed. From the rheological point of view, it was deduced that thermally treated isolates could be used as ingredients in the formulation of salad dressings. The alkaline sample would be more versatile because, depending on protein concentration and thermal treatment, the consistency of its dispersions was like that in salad dressing, or similar to those of mustard and mayonnaise.
10(S)‐Hydroxy‐8(E)‐octadecenoic acid, an intermediate in the conversion of oleic acid to 7,10‐dihydroxy‐8(E)‐octadecenoic acid
Authors: Kim Hakryul , Gardner Harold W. , Hou Ching T. 
Published: November 2006

AbstractThe new microbial isolate Pseudomonas aeruginosa (PR3) has been reported to produce from oleic acid a new compound, 7,10‐dihydroxy‐8(E)‐octadecenoic acid (DOD), with 10‐hydroxy‐8‐octadecenoic acid (HOD) being a probable intermediate. The production of DOD involves the introduction of two hydroxyl groups at carbon numbers 7 and 10, and a rearrangement of the double bond from carbons 9–10 to 8–9. It has been shown that the 8–9 unsaturation of HOD was possibly in the cis configuration. Now we report that the rearranged double bond of HOD is trans rather than cis, as determined by spectral data. Also, it was found that the 10‐hydroxyl was in the S‐configuration as determined by gas chromatographic separation of R‐ and S‐isomers after preparation of the (−)‐menthoxycarbonyl derivative of the hydroxyl group followed by oxidative cleavage of the double bond and methyl esterification. This latter result coincides with our recent finding that the main final product, DOD, is in the 7(S),10(S)‐dihydroxy configuration. In addition, a minor isomer of HOD (about 3%) with the 10(R)‐hydroxyl configuration was also detected. From the data obtained herein, we concluded that 10(S)‐hydroxy‐8(E)‐octadecenoic acid is the probable intermediate in the bioconversion of oleic acid to 7(S),10(S)‐dihydroxy‐8(E)‐octadecenoic acid by PR3.
Determination of trans fatty acids and fatty acid profiles in margarines marketed in spain
Authors: Alonso L. , Fraga M. J. , Juárez M. 
Published: November 2006

AbstractTwo gas chromatography (GC) procedures were compared for routine analysis of trans fatty acids (TFA) of vegetable margarines, one direct with a 100‐m high‐polarity column and the other using argentation thin‐layer chromatography and GC. There was no difference (P>0.05) in the total trans 18∶1 percentage of margarines with a medium level of TFA (∼18%) made using either of the procedures. Both methods offer good repeatability for determination of total trans 18∶1 percentage. The recoveries of total trans isomers of 18∶1 were not influenced (P>0.1) by the method used. Fatty acid composition of 12 Spanish margarines was determined by the direct GC method. The total contents of trans isomers of oleic, linoleic, and linolenic acids ranged from 0.15 to 20.21, from 0.24 to 0.99, and from 0 to 0.47%, respectively, and the mean values were 8.18, 0.49, and 0.21%. The mean values for the ratios [cis‐polyunsaturated/(saturated +TFA)] and [(cis‐polyunsaturated + cis‐monounsaturated)/(saturated +TFA)] were 1.25±0.39 and 1.92±0.43, respectively. Taking into account the annual per capita consumption of vegetable margarine, the mean fat content of the margarines (63.5%), and the mean total TFA content (8.87%), the daily per capita consumption of TFA from vegetable margarines by Spaniards was estimated at about 0.2 g/person/d.
Differential scanning calorimetric analysis of edible oils: Comparison of thermal properties and chemical composition
Authors: Tan C. P. , Che Man Y. B. 
Published: November 2006

AbstractThe thermal profiles of 17 edible oil samples from different plant origins were examined by differential scanning calorimetry (DSC). Two other confirmatory analytical techniques, namely gas‐liquid chromatography (GLC) and high‐performance liquid chromatography (HPLC), were used to determine fatty acid (FA) and triacylglycerol (TAG) compositions. The FA and TAG compositions were used to complement the DSC data. Iodine value (IV) analysis was carried out to measure the degree of unsaturation in these oil samples. The DSC melting and crystallization curves of the oil samples are reported. The contrasting DSC thermal curves provide a way of distinguishing among these oil samples. Generally, the oil samples with a high degree of saturation (IV<65) showed DSC melting and crystallization profiles at higher temperature regions than the oil samples with high degree of unsaturation (IV>65). Each thermal curve was used to determine three DSC parameters, namely, onset temperature (To), offset temperature (Tf) and temperature range (difference between To and Tf). Reproducibility of DSC curves was evaluated based on these parameters. Satisfactory reproducibility was achieved for quantitation of these DSC parameters. The results show that To of the crystallization curve and Tf of the melting curve differed significantly (P<0.01) in all oil samples. Our observations strengthen the premise that DSC is an efficient and accurate method for characterizing edible oils.