bluuebunny/crossref_metadata_2025 huggingface dataset:
The Cd(1–x)Mn(x)In2S4 (0.5 ≤ x ≤ 1.0) spinel system: an X‐ray powder diffraction study
Authors: Delgado G. E. , Betancourt L. , Sagredo V. , Morón M. C.
Published: November 2006

Compositions of the Cd(1–x)Mn(x)In2S4 system (0.5 ≤ x ≤ 1.0) were synthesized by the melt and annealing technique and grown by the chemical vapor transport method. The magnetic cation distributions have been estimated by X‐ray powder diffraction structure refinements using the Rietveld method. These alloys form a solid solution in all the range of compositions and crystallize with cubic symmetry in the space group Fd 3m. All phases show a spinel structure with a random arrangement of cations. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Effect of localized B and N states on the magneto‐transport of (B,Ga,In)As and (Ga,In)(N,As)
Authors: Teubert J. , Klar P. J. , Heimbrodt W. , Gottschalch V. , Lindsay A. , O'Reilly E. P.
Published: November 2006

Magneto‐transport properties of n‐ and p‐type (B,Ga,In)As and (Ga,In)(N,As) were studied in the temperature range from 2 to 300 K and in magnetic fields up to 10 T and at hydrostatic pressures up to 16 kbar. The magneto‐transport in (B,Ga,In)As and (Ga,In)(N,As) is very similar. P‐type samples show normal semiconductor behaviour whereas the electron transport in both alloys is strongly affected by the interaction of the free carriers with the density of states of localized B and N impurity states, respectively. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Structure and stability of glycine–(H2O)3 cluster and anion: Zwitterion vs. canonical glycine
Authors: Park Sung‐Woo , Im Suk , Lee Sungyul , Desfrançois C.
Published: November 2006

Calculations are presented for the glycine–(H2O) cluster anion, with glycine in canonical or zwitterionic form. The zwitterionic anions are predicted to be considerably lower in energy than the canonical anions, and the latter forms are found to be prone to isomerization to the zwitterionic anions. Therefore, we predict that the zwitterionic anions would be observed predominantly in the gas phase at low temperature. In contrast, calculated stability of neutral glycine–(H2O)3 clusters indicates that only the canonical forms of the anions would be observed in photoelectron experiments, if anions are produced from preformed neutrals. © 2006 Wiley Periodicals, Inc. Int J Quantum Chem, 2007
Optimization of microfabricated nanoliter‐scale solid‐phase extraction device for detection of gel‐separated proteins in low abundance by matrix‐assisted laser desorption/ionization mass spectrometry
Authors: Chen Wenzhang , Shen Jing , Yin Xuefeng , Yu Yingnian
Published: November 2006

A nano‐scale solid‐phase extraction (SPE) device was developed for the detection of gel‐separated proteins in low abundance by matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry (MALDI‐TOF‐MS) with a simplified microfabrication technology. By using SU‐8 photoresist instead of epoxy glue to connect the microchannel and transfer capillary, polymeric contaminant signals in MS analysis were significantly reduced. Micro SPE columns with different capacities and geometric characteristics were investigated in order to increase the detection sensitivity and decrease spot size for MALDI‐TOF‐MS analysis. It is shown that enhancements in sensitivities for the detection of proteins in low abundance were correlated with the reduction in column capacity and increase in column aspect ratio. Fifty nanoliters of matrix solution were sufficient to elute the sample completely from the optimized micro SPE column with 3.5 nL capacity. The mass spectrum of a 5 fmol in‐gel tryptic digest of bovine serum albumin (BSA), processed by the micro SPE column, demonstrated that 29 peptides matched the protein giving a sequence coverage of 51%, which was better than that obtained from analysis of 25 fmol of the same sample prepared by the dried‐droplet method. With the micro SPE column treatment of 2 µL of digestion supernatant of a gel spot of the IQGAP1 protein, 15 peptides were detected from the mass spectrum with the highest individual score of 111, while, with a ZipTip procedure, only nine peaks were detected with the highest individual score of 71. Analytical results demonstrated that this approach greatly improved the sequence coverage and identification specificity for the tested protein. It can serve as a very useful tool in proteomics studies, especially for low abundance proteins. Copyright © 2006 John Wiley & Sons, Ltd.
Music intervention for 5th and 6th graders—effects on development and cortisol secretion
Authors: Lindblad Frank , Hogmark Åsa , Theorell Töres
Published: November 2006

Objective: To investigate effects of increased music education for 5–6th graders.

Design, subjects and interventions: During the school year 1 hour music education was added each week for two classes. These were compared with classes receiving 1 hour extra data education and classes following ordinary curriculum.

Outcome measures: Questionnaires: Students were given ‘I think I am’ (measuring self‐esteem) and Social Anxiety Scale for Children‐Revised (SASC‐R) (measuring social anxiety). Parents were given Social Phobia and Anxiety Inventory‐Parental version (SPAI‐P) (measuring social phobia) and Child Behaviour Check List (CBCL) (measuring psychopathology).

Biological measures: Saliva samples for cortisol were collected on three occasions during the school year, each day four samples (at awakening, 30min later, 1h after lunch, before going to bed).

Results: The music intervention group had significantly (F = 4.98, p = 0.01) lowered levels of cortisol during the afternoon at the end of the school year. Interaction (group and time) analyses concerning afternoon cortisol levels were not significant (F = 1.97, p = 0.11). There were no significant differences over time within or between the groups on the psychological instruments.

Conclusions: Even if not conclusive, the findings suggest that the music intervention may have been of benefit. For a full‐scale investigation larger study groups are recommended and special attention to the specificity of interventions and to motivating non‐intervention classes for participating. Copyright © 2006 John Wiley & Sons, Ltd.
Relation between stress and other life style factors
Authors: Roohafza Hamidreza , Sadeghi Masoumeh , Sarraf‐Zadegan Nizal , Baghaei Abdolmehdi , Kelishadi Roya , Mahvash Masoud , Sajjadi Firoozeh , Toghianifar Nafiseh , Talaei Mohammad
Published: November 2006

Objective: To describe and evaluate the relationship between stress and other lifestyle behaviors.

Methods: A cross‐sectional study within the context of an Isfahan Healthy Heart Program (IHHP). Demographic details (age, gender, marital status and educational level) and lifestyle variables including diet (fruit and vegetable consumption), smoking status, daily physical activity and psychological distress were recorded. Data were analyzed by t‐test, χ2 and logistic regression.

Setting: Central Iranian country of Isfahan, Najaf‐Abad and Arak.

Participants: Five thousand and eight hundred and ninety‐two adults over 19 years of age.

Results: Mean age of all participants was 40.5 (15.4) years and 36 per cent of them had high stress levels. High stress levels were negatively associated with fruit and vegetable consumption, non‐smoking and marriage. Conversely, the female gender and less than 6 years of education were positively associated with stress levels. Physical activity was not found to be associated with stress.

Conclusion: This study demonstrated an association between high stress levels and other unhealthy lifestyle factors. Hence, special attention must be paid to intervention programs aimed at modifying lifestyle and providing education on stress management techniques. Copyright © 2006 John Wiley & Sons, Ltd.
Individual differences in hostility and habituation of cardiovascular reactivity to stress
Authors: Hughes Brian M.
Published: November 2006

It is well established that people with hostile interpersonal styles are at increased risk for coronary heart disease. One mechanism thought to underlie such links is cardiovascular reactivity (CVR) to stress. Despite the fact that laboratory studies have demonstrated links between hostility and CVR, questions remain as to the generalizability of such findings over time and to extra‐laboratory settings. The present study sought to focus on the relationship between hostility and separate repeated measures of CVR, thereby capturing the potential for CVR to habituate. Ninety healthy adults (45 males, 45 females) underwent standardized CVR assessments. Participants were tested twice, allowing for scrutiny of habituation patterns. All participants provided assessments of hostility based on the Cook–Medley Hostility Scale, and were categorized as either high or low on hostility. As in previous research, hostility was found to exert significant influences on diastolic blood pressure but not on systolic blood pressure or heart rate. Revealing effects of hostility on CVR habituation were found. High‐hostile participants exhibited substantial CVR habituation to stress, whereas low‐hostile participants did not. The findings reveal influences of hostility on cardiovascular functioning that would not be captured in traditional laboratory research and may reveal psychosomatic pathways between hostility and disease not previously explored. Copyright © 2006 John Wiley & Sons, Ltd.
Gender, work‐based support and family outcomes
Authors: Thompson Briony M. , Cavallaro Lauren
Published: November 2006

Work‐based support has effects on family outcomes (Thompson, Kirk, & Brown, Stress and Health, 2005, 21, 199–207), suggesting that the effects of work‐based support are transmitted to the family environment through some mediating mechanism. This study examines two potential mediating mechanisms, emotional exhaustion and work interference with family (WIF). It was expected that women would report higher levels of work support, and work support would have a stronger relationship with outcomes for women. Gender as a moderator of the relationships between work support, and emotional exhaustion, WIF, and family environment (family cohesion, family conflict) was tested via regression analyses. Eighty‐one males (43.3 per cent) and 106 females (56.7 per cent), and their spouse/partners participated in the study. Women reported higher levels of coworker support than men, and support from supervisors predicted WIF only for women. Gender did not moderate the work support—family environment relationship. WIF, but not emotional exhaustion, mediated the relationship between supervisor and coworker support, and employee reports of family cohesion. Spouse/partner reports of family environment were not predicted by the study variables. Thus, work support reduces employee negative perceptions of the family environment through reduced work–family stress, and the impact is similar for men and women. Copyright © 2006 John Wiley & Sons, Ltd.
Lateral Manipulation of Single‐Walled Carbon Nanotubes on H‐Passivated Si(100) Surfaces with an Ultrahigh‐Vacuum Scanning Tunneling Microscope
Authors: Albrecht Peter M. , Lyding Joseph W.
Published: November 2006

Ultrahigh‐vacuum (UHV) scanning tunneling microscopy (STM) can be used for the manipulation of individual atoms and molecules into complex arrangements for sensitive electrical and structural characterization. However, the systematic UHV STM manipulation of single‐walled carbon nanotubes (SWNTs), high‐aspect‐ratio molecular wires derived from graphene that exist in both semiconducting and metallic forms, has yet to be reported. In this work, we demonstrate the room‐temperature lateral manipulation of ≈1‐nm‐diameter SWNTs on UHV‐prepared, hydrogen‐passivated Si(100) surfaces. We show the reproducible actuation of SWNTs having lengths as small as 13 nm, along with the partial division of a two‐tube bundle. Moreover, UHV STM desorption of H at the SWNT/Si interface is introduced as a means of locally strengthening the interaction between the tube and the surface. The UHV STM manipulation scheme described here is potentially extensible to the orientational control of SWNTs interfaced with atomically clean semiconducting surfaces, such as InAs(110), GaAs(110), and unpassivated Si(100), for which first‐principles calculations based on density functional theory have been reported recently in the literature.
Comparison of experimental techniques used in lipid crystallization studies
Authors: Wright A. J. , Narine S. S. , Marangoni A. G.
Published: November 2006

Four methods were used to monitor the crystallization behavior of anhydrous milk fat (AMF), milk fat triacylglycerols (MF‐TAG), and MF‐TAG plus diacylglycerols (MF‐DAG). The crystallization process was monitored by measuring the solid fat content, turbidity, and scattering intensity of the crystallizing material, as well as by imaging using polarized light microscopy combined with digital image processing. In general, induction times followed the order MF‐DAG>AMF>MF‐TAG for all techniques. However, the absolute value for the induction times differed substantially; on average 3 min by microscopy, 7 min by light‐scattering spectroscopy, 13 min by turbidimetry, and 25 min by pulsed nuclear magnetic resonance. Microscopic imaging coupled to image processing proved to be the most sensitive method, suitable for the study of early events in the crystallization of fats.
Optimization of coomassie staining for quantitative densitometry of soybean storage proteins in gradient gel electrophoresis
Authors: Kwanyuen Prachuab , Wilson Richard F.
Published: November 2006

Soybean (Glycine maxL. Merr., cv. Dare) protein subunits were separated by gradient gel electrophoresis and analyzed by two‐dimensional densitometry with computer‐aided volume integration. Significant differences in the time required to achieve equilibrium staining with Coomassie Blue were revealed among the various polypeptides. Bands corresponding to lipoxygenase reached staining equilibrium in 2.7 h, whereas longer periods were required for polypeptides of β‐conglycinin (5.5 to 6.7 h) and of glycinin (8.6 to 9.2 h). These differences among polypeptides could be attributed in part to changes in gradient concentration within the polyacrylamide gel. Optimal staining intensity among all soluble proteins extracted from soybean seed was reached after staining for 8 h. Shorter than optimal staining times lead to significant underestimation of parameters such as the percentage of β‐conglycinin and glycinin of total soluble protein.
Analysis of products, mechanisms of reaction, and some functional properties of soy protein hydrolysates
Authors: Molina Ortiz Sara E. , Cristina An Mara
Published: November 2006

Soybean protein isolates were hydrolyzed with papain, bromelain, cucurbita, hieronymin, and pomiferin. The highest hydrolysis rate for cucurbita and the lowest for papain was detected at 720 min. Gel filtration, reversed‐phase liquid chromatography, and electrophoresis showed that the action of each protease was different. Pomiferin acted on the native structure of β‐conglycinin and glycinin, generating a large number of small hydrolysis products with hydrophilic and hydrophobic characteristics. The hydrolysates obtained with cucurbita showed residual structures that were almost intact and very similar to the substrate and contained a low number of small peptides. The hydrolyzates obtained with papain, bromelain, and hieronymin had hydrolysis products with structures similar to the partially hydrolyzed native isolate. The molecular masses of these products were similar to or lower than the controls. Polypeptides of low molecular mass were also detected. The prevalence of one‐by‐one and zipper mechanisms was suggested for cucurbita and pomiferin, respectively. For the other proteases both mechanisms were likely to coexist. The solubility of hydrolysates and their ability to form and stabilize foams correlated well with the structural properties and with the suggested mechanisms of hydrolysis. The best properties were presented by the hydrolysates prepared with cucurbita. Foaming ability for pomiferin hydrolysates was as high as that for unhydrolyzed soy isolate, but the foams were extremely unstable.
Influence of triacylglycerol characterics on the determination of free fatty acids in vegetable oils by fourier transform infrared spectroscopy
Authors: Verleyen T. , Verhe R. , Cano A. , Huyghebaert A. , De Greyt W.
Published: November 2006

A rapid and direct Fourier transform infrared (FTIR) spectroscopic method using a 25‐μm NaCl transmission cell was developed for the determination of free fatty acids (FFA) in six important vegetable oils (corn, soybean, sunflower, palm, palm kernel, and coconut oils) that differ in fatty acid profile. The calibrations were established by adding either standard FFA (oleic, lauric acids) or a representative mixture of FFA obtained after saponification of the refined oils. For all oils, up to a FFA level of 6.5% for coconut oil, the best correlation coefficient was obtained by linear regression of the free carboxyl absorption at 1711 cm−1. All correlation coefficients were greater than 0.993, and no significant difference between the calibration methods could be detected. Upon validation of the calibration, no significant difference (α=0.05) between the “actual” and the “FTIR predicted” FFA values could be observed. The calibration models developed for the six oils differed significantly and indicate the need to develop a calibration that is specific for each oil. In terms of repeatability and accuracy, the FTIR method developed was excellent. Because of its simplicity, quick analysis time of less than 2 min, and minimal use of solvents and labor, the introduction of FTIR spectroscopy into laboratory routine for FFA determination should be considered.
Fourier transform infrared spectroscopy and chemometrics as a tool for the rapid detection of other vegetable fats mixed in cocoa butter
Authors: Goodacre Royston , Anklam Elke
Published: November 2006

The Fourier transform infrared (FTIR) technique in combination with multivariate data evaluation was used to analyze a wide variety of cocoa butters (CB), cocoa butter equivalents (CBE), and mixtures thereof. The sample set consisted of 14 CB (10 pure from various geographical origins and 4 commercial mixtures), 18 CBE (12 mixtures and 6 pure CBE from kokum, illipé, and palm midfraction), and 154 mixtures of CB with CBE at various concentrations (ranging from 5 to 20%). A total of 192 samples were analyzed in triplicate. All CB and CBE were shown to have very characteristic FTIR spectra that gave highly reproducible fingerprints. The main vibrational modes were also elucidated. FTIR can easily be employed to distinguish between pure CB and pure CBE. With prior knowledge of which cocoa butter is present in mixtures, FTIR can be applied to distinguish between CB mixed with CBE at the 10 and 20% levels (corresponding to about 2 and 5% of CBE in chocolate). However, the study revealed that a single “global” statistical model (multilayer perceptron, radial basis functions, or partial least square regression) was not able to predict the precise level of addition. The FTIR approach detailed here shows great potential as a rapid screening method for distinguishing between pure vegetable fats and, we believe, could be extended to investigate mixtures of CB and CBE by the establishment of a database.
Viscosity estimation of triacylglycerols and of some vegetable oils, based on their triacylglycerol composition
Authors: Azian M. Noor , Mustafa Kamal A. A. , Panau F. , Ten W. K.
Published: November 2006

The experimentally determined kinematic viscosities of simple triacylglycerols [trilaurin, trimyristin (MMM), tripalmitin (PPP), tristearin (SSS), triolein (OOO), and trilinolein (LiLiLi) were correlated to a modified Andrade‐type equation. The constants for the modified equation were derived for each simple triacylglycerol. The method was also used to estimate the viscosity of mixed triacylglycerols [1,2‐dimyristoyl‐3‐palmitoyl (MMP), 1,2‐dioleoyl‐3‐palmitoyl (OOP), 1,2‐dimyristoyl‐3‐oleoyl (MMO), and 1,2‐dipalmitoyl‐3‐oleoyl (PPO)], binary triacylglycerol mixtures (PPO/OOP, PPP/SSS, and OOO/SSS of different portions), and three types of vegetable oils [refined, bleached, and deodorized palm oil; cocoa butter; and canola oil] by applying modified Kay’s rule utilizing the simple triacylglycerol constants derived earlier. In all cases, the estimated values for liquid viscosity were compared with experimental values determined in this work and with previous work from the literature. When applied to vegetable oils, the method requires knowledge of their triacylglycerol composition. Despite its simplicity, the method gives a reasonable estimate. The method may be used to predict the viscosity of different blends of vegetable oils, and the accuracy is expected to increase when more experimental data on simple triacylglycerols become available.
Identification and quantification of cholesterol oxidation products in canned tuna
Authors: Zunin Paola , Boggia Raffaella , Evangelisti Filippo
Published: November 2006

Cholesterol oxidation in tuna canned in brine was studied. Gas chromatography‐mass spectrometry was used for the detection of the seven major cholesterol oxidation products originating from both direct and indirect oxidation. The total amount of cholesterol oxidation products in the analyzed samples varied considerably, ranging between 40 and 350 μg/g lipids, with the exception of an anomalous sample, that reached a 1600 μg/g level. The lipid content ranged between 0.5 and 1 g/100 g wet product. As most samples did not exceed 100 μg/g lipids, it is possible to assume that the total content of cholesterol oxidation products can be kept below this value if good manufacturing conditions are used, together with a careful choice of the best tuna cuts. The application of principal component analysis to the detected variables confirmed that 7‐ketocholesterol is a useful index of the whole oxidation process.
The effect of bleaching and physical refining on color and minor components of palm oil
Authors: Rossi M. , Gianazza M. , Alamprese C. , Stanga F.
Published: November 2006

An industrially degummed Indonesian palm oil was bleached and steam refined in a pilot plant to study the effect of processing on oil color and on the levels of carotenoids and tocopherols. Five concentrations of one natural and two activated clays mixed with a fixed amount of synthetic silica were used for bleaching. For color measurement, the Lovibond method was compared to the CIE (Commission Internationale de l’Eclairage) L*,a*,b* method. The results showed that the L*,a*,b* method is repeatable and that the values found are highly correlated with the carotenoid content of bleached oil samples. The various clays and synthetic silica mixes removed 20–50% of the carotenoids in the degummed oil, depending on clay concentration and activity. For the two activated clays, pigment adsorption increased with clay amount. Steam refining totally destroyed carotenoids in the claytreated oils by heat bleaching. Total tocopherols in the crude oil amounted to 1000 mg/kg, with γ‐tocotrienol as the main tocopherolic component followed by α‐tocopherol, α‐tocotrienol, and δ‐tocotrienol. Tocopherol concentrations increased after the bleaching treatment with the most acid clay, and the increase was proportional to the amount of clay used. Both bleaching and steam refining changed the ratios between the various to copherolic components, especially increasing the relative concentration of α‐tocotrienol in the refined oil. An average 80% tocopherol retention was obtained after the treatment with acid clay + synthetic silica and steam refining of palm oil.
Solvent engineering applied to lipase‐catalyzed glycerolysis of triolein
Authors: Rendón X. , López‐Munguía A. , Castillo E.
Published: November 2006

Solvent engineering was applied to lipase‐catalyzed glycerolysis of triolein for the selective synthesis of monoolein and diolein. The effect of different binary mixtures of n‐hexane and 2‐methyl‐2‐butanol (2M2B) on the selective production of mono‐ or diacylglyceride was established. Conditions for high selectivity toward monoolein synthesis were enhanced from 10.6 mol% in pure n‐hexane to 64 mol% in 2M2B. On the contrary, the highest production of diolein, corresponding to 62 mol%, was achieved in n‐hexane. Concerning triolein conversion, the best results were obtained in 100% 2M2B, with a conversion of 75%. The effect of the n‐hexane/2M2B ratio on diolein regioisomer production during triolein glycerolysis was also evaluated. Two different profiles of diolein regioisomers were observed as a function of solvent composition: Although the production of the 1,2‐diolein isomer was favored as the proportion of 2M2B in n‐hexane was increased, the 1,3‐isomer was preferentially synthesized in reactions where n‐hexane was the predominant solvent. When 100% n‐hexane was used as a solvent, 1,3‐diolein comprised 72 mol% of the total diolein population (58 mM). On the contrary, when the reaction was carried out in 100% 2M2B, the total concentration of diolein was lower (21 mM) but the 1,2‐diolein regioisomer was preferentially formed (89%). These results were explained as a consequence of the different extents of hydrolysis‐synthesis reactions involved in the glycerolysis process, which are strongly dependent on solvent mixtures and water concentration. Finally, some advantages of the use of binary mixtures of solvents compared with other strategies applied to glycerolysis reactions are discussed.
Lipolytic activity of California‐laurel (Umbellularia californica) seeds
Authors: Haas Michael J. , Cichowicz David J. , Dierov Jamil Kh.
Published: November 2006

The lipid content of dormant mature seeds of the California‐laurel (Umbellularia califonnica) was 74% (mass basis) and decreased upon germination, reaching 43% 5 wk after germination. Dormant seeds contained only barely detectable lipase activity. Lipase activity rose upon germination, peaking 2 to 3 wk after the onset of visible germination. The combined addition of three detergents, 3‐[(3‐cholamidopropyl)dimethylammonio]‐1‐propane‐sulfonate (1 mM), taurocholic acid (1 mM), and Tween‐20 (0.05%, vol/vol) during homogenization increased the lipolytic activity of total seedling homogenates by about 60%. Following centrifugation of homogenates from seedlings of various ages, ca. 80% of the recovered lipolytic activity was located in the fat‐free supernatant, with the remainder in the floating fat pad. The crude seed lipase did not show hydrolytic specificity for glycerol esters of lauric acid (the predominant fatty acid of the seed triglycerol): comparable lipolytic activities were seen toward olive oil, trilaurin, tripalmitin, and tristearin. Maximal lipolytic activity occurred at pH 8.5. This activity was stable over the pH range 6 to 9, and unstable at >40°C in a fashion that suggested the presence of multiple enzymes with different substrate specificities. Two lipolytic species, one of which showed some selectivity toward lauric acid esters, were partially separated from one another by ion‐exchange chromatography.
Application of two heating methods in physical refining of high‐FA olive and sunflower oils
Authors: Bada Gancedo J. C. , Prieto González M. M. , Xiberta Bernat J. , Graciani Constante E. , León Camacho M.
Published: November 2006

Two classes of vegetable oils, olive and sunflower, were processed by physical refining in a pilot plant with a capacity of up to 30 L by means of discontinuous deodorization, and distillates were recovered by condensing and freezing using steam and nitrogen as stripping gases. Two heating systems were evaluated in the deodorizer. In the first, the deodorizer oil and the distilled gases were heated so as to maintain the same temperature in both. In the second, only the oil was heated, resulting in a difference in temperature between the oil and the distilled gases. In addition, two different oil temperatures were evaluated for each stripping gas. By means of the first heating system, the deacidification time for both oils was reduced and the efficiency of the process was notably improved. On the other hand, the higher temperature had a negative influence over both parameters. For both heating systems the sterol contents did not suffer significant variations. Substantial variations in trans FA were not observed, and the composition of FA remained stable except for linoleic acid, which decreased, although more slowly than when the temperature was not maintained, as a result of the rapid formation of its trans FA.
Characterization and supercritical carbon dioxide extraction of walnut oil
Authors: Oliveira Rui , Fátima Rodrigues M. , Gabriela Bernardo‐Gil M.
Published: November 2006

Walnut (Juglans regia L.) oil was extracted with compressed carbon dioxide (CO2) in the temperature range of 308 to 321 K and in the pressure range of 18 to 23.4 MPa. The influence of particle size was also studied at a superficial velocity of 0.068 cm/s, within a tubular extractor of 0.2 L capacity (cross‐sectional area of 16.4 cm2). FFA, sterol, TAG, and tocopherol compositions were not different from those of oil obtained with n‐hexane. The main FA was linoleic acid (56.5%), followed by oleic acid (21.2%) and linolenic acid (13.2%). The main TAG was LLL (linoleic, linoleic, linoleic) (24.4%), followed by OLL (oleic, linoleic, linoleic) (19.6%) and LLLn (linoleic, linoleic, linolenic) (18.4%). The main component of sterols was β‐sitosterol (85.16%), followed by campesterol (5.06%). The amount of cholesterol was low (0.31 and 0.16% for oils extracted by n‐hexane and supercritical fluid extraction, respectively. The CO2‐extracted oil presented a larger amount of tocopherols (405.7 μg/g oil) when compared with 303.2 μg/g oil obtained with n‐hexane. Oxidative stability determined by PV and the Rancimat method revealed that walnut oil was readily oxidized. Oil extracted by supercritical CO2 was clearer than that extracted by n‐hexane, showing some refining. A central composite, nonfactorial design was used to optimize the extraction conditions using the software Statistica, Version 5. The best results were found at 22 MPa, 308 K, and particle diameter (Dp) −0.1 mm.
Supercritical CO2 extraction of flaxseed
Authors: Bozan B. , Temelli F.
Published: November 2006

Extraction of flaxseed oil was performed with supercritical carbon dioxide (SC‐CO2). To investigate the effects of pressure and temperature on the solubility of oil and oil yield, three isobaric (21, 35, and 55 MPa) and two isothermal (50 and 70°C) extraction conditions were selected. Although the maximal solubility of flaxseed oil, 11.3 mg oil/g CO2, was obtained at 70°C/55 MPa, the oil yield obtained after 3 h of extraction at this condition was only 25% (g oil/g seed×100), which represented 66% of the total available oil of the flaxseed. Lipid composition and FFA and tocol (tocopherol and tocotrienol) contents of the oils obtained by both SC‐CO2 and petroleum ether extraction were determined. The α‐linolenic acid content of the SC‐CO2‐extracted oil was higher than that obtained by solvent extraction.
Determination of squalene in olive oil using fractional crystallization for sample preparation
Authors: Nenadis Nikolaos , Tsimidou Maria
Published: November 2006

A simple, rapid method for the determination of squalene in virgin olive oil was developed using RP‐HPLC with detection at 208 nm. Fractional crystallization from methanol/acetone (7∶3, vol/vol) was applied to obtain squalene in the liquid fraction of the oil prior to HPLC. Elution of squalene was then carried out isocratically with acetone/acetonitrile (40∶60 vol/vol) within 11 min. The detection limit was 23 mg/kg, and the limit of quantification 79 mg/kg. The precision of the crystallization procedure (CV%=3.76, n=7) and the mean recovery (92.5 and 81.5% for the 7,000 and 700 mg/kg levels of addition, respectively) were satisfactory. The method is easily applicable to fulfill future needs for nutrition labeling.
Synthesis of geranyl acetate by esterification with lipase entrapped in hybrid sol‐gel formed within nonwoven fabric
Authors: Chen Jyh‐Ping , Lin Wei‐Shin , Chang Min‐Far
Published: November 2006

Candida cylindracea lipase was entrapped in organic‐inorganic hybrid sol‐gel polymers made from tetramethoxysilane (TMOS) and alkyltrimethoxysilanes. By forming the gels within the pores of a nonwoven polyester fabric, a novel immobilized biocatalyst in sheet configuration based on sol‐gel en‐trapment of the enzyme was obtained. Lipases immobilized in sol‐gel matrices efficiently catalyzed the direct esterification reaction of geraniol and acetic acid in anhydrous hexane to produce geranyl acetate. The optimal formulation of the sol‐gel solution for enzyme immobilization was at a 20∶1 molar ratio of water to total silane; a 4∶1 molar ratio of propyltrimethoxysilane to TMOS; hydrolysis time at 30 min; and enzyme loading of 200 mg lipase/g gel. Under these conditions, protein immobilization efficiency was 91%, and the specific activity of the immobilized enzyme was 2.6 times that of the free enzyme. Excellent thermal stability was found for the immobilized enzyme in dry form or in hexane solution in the presence of acetic acid, in which case severe inactivation of free enzyme was observed. The immobilized enzyme retained its activity after heating at 70°C for 2 h, whereas the free enzyme lost 80% of its activity.
Specific heats of cottonseed and its co‐products
Authors: Wan Peter J. , Zarins Zigrida M.
Published: November 2006

Most of the annual crop of cotton is harvested and stored for the entire crushing season until the new crop year begins. It is desirable to have specific heat data of agricultural materials so the engineer can manage the heat transfer problem associated with each crop during storage. Thermal properties of agricultural products, such as cottonseed and its oil mill co‐products, are not commonly available. Partially because these materials are bulky and lack uniformity, their thermal properties are difficult to assess precisely. The highly sensitive and large‐sample volume differential scanning calorimeter has made the precise determination of specific heat of agricultural material possible. This report describes a procedure used to obtain the specific heat of white cottonseed and its co‐products as a function of temperature. The materials tested included cotton fiber, whole cottonseed, linters, hulls, meats, and meal. Specific heat values of these materials ranged from 0.32 to 0.6 cal/g/°C at 30°C and 0.42 to 0.72 cal/g/°C at 90°C. When these materials were dried, the values converged to 0.24 to 0.33 cal/g°C at 30°C.
Phospholipid class and FA compositions of modified soybeans processed with two extraction methods
Authors: Wu Yingzi , Wang Tong
Published: November 2006

Soybean lecithin is used as an emulsifier in food, cosmetic, and pharmaceutical industries. The proportion of individual phospholipids (PL) and their FA composition may affect the functional properties of lecithin. In this research, lecithins recovered from four modified soybeans and one commodity soybean, which were processed by extrusion‐expelling and conventional solvent extraction, were analyzed for proportion of PL class and FA composition. HPLC with an ELSD analysis demonstrated that the percentage of PC in extrusion‐expelled lecithin was higher than in solvent‐extracted lecithin, whereas the PE content was lower. GC analysis showed that FA compositions of the PL varied with soybean type. The oil extraction method did not significantly affect FA composition. Critical micelle concentration tested with a tensiometer showed differences among the lecithins.
Protein enrichment of defatted salicornia meal by air classification
Authors: Wu Y. Victor , Abbott Thomas P.
Published: November 2006

Salicornia bigelovii Torr. is a leafless, annual salt‐marsh plant. Previous investigators reported that the seed contained 26 to 33% oil, 30 to 33% protein, 5 to 7% fiber, and 5 to 7% ash. Hexane‐defatted salicornia meal was ground in a pin mill and separated by air classification into various fractions by particle size. The fine fractions were enriched in protein. The degree of protein enrichment and yield of fine fractions depended on the intensity of grinding. More intense grinding resulted in a higher yield of fine fractions with a smaller increase in protein content compared with less intensive grinding. The amino acid composition and proximate composition of the air‐classified fractions are compared with the starting material.
Volatile by‐products during heat polymerization of soybean oil
Authors: Erhan Sevim Z. , Sheng Quan , Hwang Hong‐Sik
Published: November 2006

Volatile by‐products during heat polymerization of soybean oil at 330°C were analyzed using GC‐MS and NMR. Color and viscosity changes were monitored for the heat‐polymerized soybean oil and the by‐products. About 90% (w/w) of the by‐products were decanoic, palmitic, linoleic, oleic, and stearic acids and cis‐9‐tricosene. The by‐products also contained small amounts of 3‐eicosene, 9,17‐octadecadienal, and cyclotetracosene. The weight percentage of decanoic acid increased with reaction time, whereas those of other components showed no trends.
Microscale recovery of total lipids from fish tissue by accelerated solvent extraction
Authors: Dodds Eric D. , McCoy Mark R. , Geldenhuys Adeline , Rea Lorrie D. , Kennish John M.
Published: November 2006

A number of techniques are available for the extraction of lipids from a variety of tissues; however, conventional methods are characteristically labor intensive, typically involve large volumes of toxic solvents, and usually require at least 1 g of tissue. With the availability of accelerated solvent extraction (ASE) technology, the opportunity exists to modify classical lipid extraction techniques such that automated high‐pressure, high‐temperature extractions may be performed with the use of far smaller volumes of costly and harmsul solvents. Moreover, the high extraction efficiency attainable by ASE suggests that significantly less tissue would be required than is routinely used. This paper describes the adaptation of previously developed lipid extraction solvent systems for use with ASE toward the purpose of extracting total lipids from 100 mg of fish tissue. The efficacy of three solvent systems for lipid extraction from representative fish tissues, including a standard reference material, was explored using gravimetry and FA analysis by GC. A TG was used as a surrogate to monitor overall method performance. The findings herein demonstrate that microscale ASE represents an effective and efficient alternative to traditional lipid extraction techniques based on quantity and composition of extracted lipid, surrogate recovery, and precision.
Epoxide yield determination of oils and fatty acid methyl esters using 1H NMR
Authors: Aerts Hans A. J. , Jacobs Pierre A.
Published: November 2006

Product mixtures of epoxidized fatty compounds can be analyzed by using 1H NMR. Conversion of double bonds and selectivities to different products can easily be calculated. Moreover, if diunsaturated substrates are used in epoxidation reactions, yields to mono‐ and diepoxidized products can be determined. The effectiveness of this method is proven by comparing some NMR results with those found by GC analysis.
Frying oil and fat quality measured by chemical, physical, and test kit analyses
Authors: Sanibal E. A. A. , Mancini‐Filho J.
Published: November 2006

The performance of soybean oil (SBO) and a partially hydrogenated soybean oil (PHSBO) was monitored by chemical, physical, and test kit analyses during 50 h of deep‐frying of potatoes in SBO and 50 h of deep‐frying of potatoes in PHSBO. The oxidative stability of SBO and PHSBO was measured by the iodine value, color index, FFA content, total polar compounds, and FA analysis of deep‐frying SBO and PHSBO. SBO, with higher levels of unsaturated FA, had the faster rate of formation of geometric and positional isomers of unsaturated FA as measured by GC with standards. PHSBO performance under deep‐frying conditions was significantly better than SBO with respect to iodine value, color index, and total polar compounds. The results from analyses using test kits had a good correlation with analytical parameters.
Synthesis of a fatty tetrahydroxyamide using peroxygenase from oat seeds
Authors: Piazza George J. , Foglia Thomas A.
Published: November 2006

Prior work has shown that oat (Avena sativa) seeds are a rich source of lipase and peroxygenase. Partial epoxidation of the isobutyl amide derivative of α‐linolenic acid with peroxygenase gave N‐i‐butyl‐9, 10–15, 16‐diepoxy‐12(Z)‐octadecenamide, a diepoxide product in which the epoxides reside only at the formerly external double bond positions. No amide hydrolysis occurred during the epoxidation procedure. Hydrolysis of the diepoxide gave N‐i‐butyl‐9, 10,15,16‐tetrahydroxy‐12 (Z)‐octadecenamide, a polyol derivative with relatively high polarity, potentially useful in developing new materials from fats and oils.
Impact of sample preparation on the determination of crude fat content in corn
Authors: Luthria Devanand L. , Noel Kirk , Vinjamoori Dutt
Published: November 2006

Sample preparation is an important step in any analysis as it directly affects the assay results. The effect of sample preparation on the extraction of crude fat from 10 corn samples with varying fat content was studied. Samples were ground on seven different grinders, namely, the Mega‐grinder, Knifetec, Cyclotec, Cemotec, Mikro‐mill, UDY, and Brinkmann‐Retsch mill. The crude fat was extracted from ground samples using Soxtec and/or Butt‐tube extraction procedures and was determined gravimetrically after evaporation of the extraction solvent. The lowest amount of crude fat was extracted from samples ground on a Cemotec grinder. However, similar yields of crude fat were obtained with the other six sample preparation mills by using the proper screen size and grinding conditions. We observed an increase of 0.3% in the grand mean of crude fat extracted from samples ground on a Cyclotec grinder fitted with a 1.0‐mm screen as compared with a 2.0‐mm screen. Modifying the grinding time from 5 to 10 s/cycle and increasing the number of cycles from 2 to 3 resulted an increase of 0.4% in the grand mean of crude fat extracted from 10 corn samples. No significant differences were observed in crude fat content when samples were ground with a Monsanto‐built Mega‐grinder, located at two different sites. The efficiency of crude fat extracted from ground samples was found to increase with the decrease in particle size.
Quantitative trait loci for β‐conglycinin (7S) and glycinin (11S) fractions of soybean storage protein
Authors: Panthee D. R. , Kwanyuen P. , Sams C. E. , West D. R. , Saxton A. M. , Pantalone V. R.
Published: November 2006

Glycinin (11S) and β‐conglycinin (7S) are important seed storage proteins in soybean [Glycine max (L.) Merr.]. A major limitation of soybean seed storage proteins is their low levels of the sulfur‐containing amino acids, methionine and cysteine, which are important nutritional components of protein mea. Glycinin contains significantly more S‐containing amino acids than does β‐conglycinin. Thus, detection of quantitative trait loci (QTL) that govern 11S may provide marker‐assisted selection (MAS) opportunities to improve soybean total S‐containing amino acids. The objective of this study was to detect and map QTL governing 7S and 11S fractions of soybean seed storage proteins. To achieve this objective, 101 F6‐derived recombinant inbred lines (RIL) developed from a cross of N87‐984‐16 ×TN93‐99 were used. Storage proteins were extracted from all RIL and separated in 10–20% linear gradient polyacrylamide gels. Dried gels were scanned for individual subunits of storage protein with a densitometer equipped with a He−Ne laser light source. Data were converted to concentration for each subunit component and analyzed using SAS software. A significant (P<0.05) difference among genotypes was found for glycinin and β‐conglycinin. A total of 94 polymorphic simple sequence repeat molecular genetic markers were used in screening all RIL. Three QTL for glycinin (Satt461, Satt292, and Satt156) were distributed on linkage group (LG) D2, I, and L, respectively, whereas two QTL for conglycinin (Satt461 and Satt249) were distributed on LG D2 and J. Phenotypic variation explained by individual QTL ranged from 9.5 to 22%. These QTL may provide useful MAS opportunities for improvement of nutritional quality in soybean.
Fatty acids and oil content in white lupin seed as affected by production practices
Authors: Bhardwaj Harbans L. , Hamama Anwar A. , van Santen Edzard
Published: November 2006

Characteristics of the seed oil of white lupin (Lupinus albus L.), a potential alternative winter crop in the mid‐Atlantic region of the United States, are not well established. Replicated experiments were conducted during the 1998–1999 and 1999–2000 growing seasons with a determinate and an indeterminate cultivar to characterize oil and FA in lupin seed in relation to production practices. The experiments were planted in early October, late October, and mid‐November using row spacings of 0.3, 0.6, and 0.9 m at each planting time. Seeds from the planting date of early October had significantly (P<0.05) higher oil content than the later plantings (late October and mid‐November). A closer row spacing (0.3 m) also had significantly (P<0.05) higher oil content than the wider row spacing (0.9 m). Planting data effects on FA content were significant for some FA, but row spacing did not affect FA contents. Oil content in the seed varied from 7.2 to 8.2% (w/w). The oil from white lupin seed contained FA in the order of 18∶1>18∶2> 18∶3>16∶0>20∶1>22∶1>22∶0>18∶0>24∶0>20∶0. The saturated FA/unsaturated FA ratio in lupin oil was 0.14. White lupin seed contained higher contents of oil and FA than literature values for seed of navy, kidney, and pinto beans.
Tocopherol oil concentration in field‐grown sunflower is accounted for by oil weight per seed
Authors: Nolasco S. M. , Aguirrezábal L. A. N. , Crapiste G. H.
Published: November 2006

Tocopherols are natural antioxidants that increase the stability of fat‐containing foods and perform important biological activities. Significant variations (389 to 1873 μg g oil−1) in the total tocopherol concentration of sunflower seed oil have been reported. The main objectives of this work were to determine the influence of intercepted photosynthetically active radiation on tocopherol concentration during seed filling and to establish and validate relationships between tocopherol concentration in oil and other quality variables of the seed. Seven sunflower hybrids were grown under good water and nutritional conditions in two similar experiments carried out in two contrasting environments. Treatments were applied to modify the amount of radiation intercepted per plant during seed filling in order to obtain a range in oil yield per plant and its components. Greater per plant intercepted radiation decreased the tocopherol concentration in oil. Tocopherol concentration decreased when oil weight per seed increased. Tocopherol concentration stabilized for oil weight per seed higher than 23 mg oil seed−1. This exponential relationship accounted for 73% of the variability in tocopherol concentration (507 to 1203 μg g oil−1) despite differences in hull type, locations, hybrids, and radiation treatments. The proposed relationship acceptably predicted independent results. Crop management techniques could lead to seeds with greater concentrations of tocopherols.