bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ternary phase diagram of soybean phosphatidylcholine‐water‐soybean oil and its application to the water degumming process
Authors: Lei Ling , Ma Yue , Kodali Dharma R. , Liang Jingmei , Davis H. Ted 
Published: November 2006

AbstractCrude soybean oil contains phospholipids (2.5 wt%) that must be removed from oil during processing. A common method is the water‐degumming process. A ternary phase diagram of soybean oil‐water‐soybean PC, a major component of phospholipids, was established. From this diagram, phase transitions and compositions of phases can be determined. A theoretical model describing the relationship between aggregation curvature and the amount of water added is presented to explain the phase transitions. The amount of water absorption by the lamellar phase should be larger than the critical value of 34 wt% based on the total weight of water and PC. Below this critical amount, phospholipids tend to form liposomes. Above the critical point and below the saturation point, larger aggregates of particles form and can be easily separated. When more water is added to reach the water adsorption limit, about 40 wt% based on the total weight of water and PC, a phase transition boundary is observed, beyond which a third phase, water, appears and the particle size falls dramatically. In between the critical line predicted by the model and the water adsorption saturation line observed experimentally, there is an operation window on the ternary phase diagram for the water‐degumming process.
Effect of crop season on the composition of virgin olive oil with protected designation of origin “Les garrigues”
Authors: Romero M. Paz , Tovar M. Jesús , Ramo Tomas , Motilva M. José 
Published: November 2006

AbstractIn recent years a growing demand for agricultural produce with an identifiable geographical origin has developed. The aim of this work was to study differences in quality and composition of virgin olive oils produced over four consecutive crop seasons in the region of the protected designation of origin “Les Garrigues” (Catalonia, Spain), taking the harvesting period and the climatic conditions of the year into consideration. The results obtained in this study indicate that virgin olive oil composition is greatly influenced by climatic conditions, mainly the cumulative rainfall in the case of FA composition and phenolic compounds, and the minimum temperatures during harvest period in the case of chlorophyll, carotenoid pigments, and α‐tocopherol content. The harvest period influenced most of the parameters analyzed, apart from the PV and FFA content. Prediction models for carotenoid pigment content, oxidative stability, and bitter index were found.
An experimental approach to structure‐activity relationships of caffeic and dihydrocaffeic acids and related monophenols
Authors: Nenadis Nikolaos , Boyle Susanne , Bakalbassis Evangelos G. , Tsimidou Maria 
Published: November 2006

AbstractThe importance of a catechol moiety to the radical‐scavenging activity of p‐hydroxycinnamic derivatives is widely accepted, whereas the role of the carbon side chain remains controversial. Extension of the conjugation to this chain is a molecular feature that requires some attention. Differences in the activity of caffeic and dihydrocaffeic acids were examined using a series of experimental procedures: assays using free radicals [1,1‐diphenyl‐2‐picrylhydrazyl (DPPH•) and 2,2′‐azino‐bis(3‐ethylbenzthiazoline‐6‐sulfonic acid) (ABTS•+)]; assays based on redox reactions; and accelerated tests in bulk oils and dispersed systems. To reinforce observations on the role of the side chain, a group of related monophenols, differing in one double bond and/or its position in the chain, was also examined. Extended conjugation was essential for the rapid scavenging of free radicals and for effectiveness in dispersed systems (both liposomes and emulsions). In the case of bulk oils, the contribution of conjugation remained unclear. Information based on redox reactions was not useful for the aim of our study. The experimental conditions may mask or enhance the effect of the chain characteristics on the activity, so the size and the order of activity may be influenced. Thus, structure‐activity relationships should be drawn with caution.
Pan‐frying stability of NuSun oil, a mid‐oleic sunflower oil
Authors: Kiatsrichart Sudatip , Susan Brewer M. , Cadwallader Keith R. , Artz William E. 
Published: November 2006

AbstractPan‐frying is a popular frying method at home and in many restaurants. Pan‐frying stabilities of two frying oils with similar iodine values (IV)—mid‐oleic sunflower oil (NuSun oil; IV=103.9) and a commercial canola oil (IV=103.4)—were compared. Each oil sample was heated as a thin film on a Teflon‐coated frying pan at ∼180°C to a target end point of ≥20% polymer. High‐performance size‐exclusion chromatography analysis of the mid‐oleic sunflower and canola oil samples indicated that the heated samples contained 20% polymer after approximately 18 and 22 min of heating, respectively. The food oil sensor values increased from zero to 19.9 for the canola sample and from zero to 19.8 for the mid‐oleic sunflower sample after 24 min of heating. The apparent first‐order degradation rate for the mid‐oleic sunflower sample was 0.102±0.008 min−1, whereas the rate for the canola sample was 0.092±0.010 min−1. The acid value increased from approximately zero prior to heating to 1.3 for the canola sample and from zero to 1.0 for the mid‐oleic sunflower sample after 24 min of heating. In addition, sensory and volatile analyses of the fried hash browns obtained from both oils indicated there were no significant differences between the two fried potato samples.
Analysis of the polyethylene glycol glucosides and FA esters thereof by atmospheric‐pressure ionization MS
Authors: Jin Xin , Yang Jinzong , Tang Bingtao , Zhu Minggui , Yu Ning , Liu Yi 
Published: November 2006

AbstractPolyethylene glycol (PEG) glucosides (PEGG) and the PEGG esters of lauric acid were analyzed by atmospheric‐pressure ionization MS (API‐MS) with electrospray ionization. Straightforward mass characterization of the complex mixtures could be achieved without prior chromatographic separation. The constituents were identified on the basis of quasi‐molecular ions. Individual components could be observed as protonated molecular ions [M+H]+and/or as their NH4+, Na+, or K+adducts in positive ion mode. The mass spectrometric investigation showed that mixtures of PEGG consisted of monoglucoside, diglucoside, polyglucoside, and free PEG. The esterification product is a mixture of two types of nonionic surfactants: PEG‐laurates and PEGG‐laurates. The reasons for distortion of the quasi‐molecular ion intensities and the stabilization of adduct ions were discussed. The rapid and highly sensitive API‐MS analysis technique proposed here is well suited for direct characterization of complex mixtures and suitable for development as a routine analytical method.
DSC determination of thermally oxidized olive oil
Authors: Vittadini E. , Lee J. H. , Frega N. G. , Min D. B. , Vodovotz Y. 
Published: November 2006

AbstractThe feasibility of using DSC as an analytical method to evaluate the autoxidation of olive oil at 50°C and thermal oxidation at 93 and 180°C in 10‐mL airtight vials was studied. DSC peak enthalpy and peak crystallization temperatures were compared with headspace oxygen depletion and headspace volatiles in oxidized oil samples. A single crystallization peak was found in olive oil. The crystallization peak shifted to lower temperatures, and the enthalpy associated with this phase transition decreased as the exposure time increased at 93 and 180°C. DSC peak enthalpy in olive oil at 50, 93, and 180°C showed correlations of 0.84, 0.91, and 0.95, respectively, with headspace oxygen depletion in sample bottles. Correlation of DSC initial peak temperature with headspace oxygen depletion was 0.53, 0.87, and 0.95 at 50, 93, and 180°C, respectively. Correlations of DSC peak enthalpy and initial peak temperature with headspace volatiles at 180°C were 0.95 and 0.97, respectively. These results indicate that DSC is a good analytical method to determine the oxidative stability of olive oil at frying temperature.
Determination of degree of oxidation of methyl linoleate and linolenate by weighing method
Authors: Matikainen Jorma , Laantera Matti , Kaltia Seppo 
Published: November 2006

AbstractAutoxidation of methyl linolenate and linoleate was investigated at room temperature in the light and dark during a period of 2 mon using a weighing method accompanied with 1H NMR measurements. In the light, the increase in weight, or autoxidation process, of the two compounds began immediately after the start of the experiment. In the dark, the weight of methyl linolenate began to increase after a delay of 1 wk, and the weight of methyl linoleate after 40 d. The maximal increases in the weights of the compounds were somewhat greater in the dark than in the light; the weight of methyl linolenate in the dark increased by 22.3% and in the light by 20.8%. The corresponding values for methyl linoleate were 16.9 and 14.4%, respectively. Results of the NMR measurements were compared to the weighing results, and a table was constructed representing the correlation between selected multiplets and corresponding weight increments.
Novel method for rapid monitoring of lipid oxidation by FTIR spectroscopy using disposable IR cards
Authors: Russin Ted A. , van de Voort Frederick R. , Sedman Jacqueline 
Published: November 2006

AbstractA new FTIR approach was investigated for assessing edible oil oxidative stability with the use of polymer IR (PIR) cards as sample holders. This approach allows oil oxidation to be monitored at moderate temperatures owing to the fairly rapid rate at which unsaturated oils oxidize on the PIR cards. To assess the FTIR/PIR card method, pure TAG—triolein, trilinolein, and trilinolenin—were loaded onto cards and placed in a chamber where warm air (55°C) flowed over them continuously to facilitate oxidation. At periodic intervals, individual cards were removed and their FTIR spectra scanned, after which they were replaced in the aeration chamber. All spectra were normalized to compensate for variations in PIR card path lengths or oil loadings, and for each card the initial spectrum recorded (t=0) was subtracted from all subsequent spectra taken over time to produce differential spectra. With the use of a peak‐find algorithm, the absorbance minimum in the cis region (3017–3000 cm−1) and the absorbance maxima in the hydroperoxide (3550–3200 cm−1), isolated trans (977–957 cm−1), and conjugated trans regions (995–983 cm−1) were measured in the differential spectra and plotted as a function of time. For all three TAG, the loss of cis double bonds was linearly related to the development of hydroperoxides and isolated trans bonds for much of the oxidation process, whereas for the polyunsaturated TAG a similar relationship also existed for conjugated trans species. Based on experimentally determined hydroperoxide (ROOH) absorbance slope factor (0.06 mAbs/PV), ROOH absorbance changes were converted to PV, allowing direct PV monitoring as a function of time using the PIR cards. Trilinolenin, trilinolein, and triolein attained a PV of 100 mequiv/kg oil after, 43,98, and 2889 min, respectively, their relative reaction rates being similar to ratios published in the literature. The assessment of the FTIR/PIR card method using TAG indicates that it may be a practical and rapid means of oxidizing lipids and tracking their oxidative state in terms of PV so as to provide a measure of their oxidative stability.
Characterization of supercritical fluid extracts from raw wool by TLC‐FID and GC‐MS
Authors: Domínguez C. , Jover E. , Garde F. , Bayona J. M. , Erra P. 
Published: November 2006

AbstractExtraction selectivity of whole wool wax from raw wool by using ethanol‐modified carbon dioxide at constant pressure (100 bar) and temperature (60°C) was studied. A kinetic study was carried out to optimize the percentage of ethanol and the extraction time. The modified carbon dioxide was decompressed in ethanol as a collection solvent, leading to the formation of two different fractions as a function of their solubility. Qualitative and quantitative analyses of the lipid classes present in the collected fractions were performed by TLC coupled to an automated FID system (TLC‐FID). Moreover, a detailed structural comparison was carried out between the aliphatic high‐molecular‐mass esters and the steryl ester patterns by means of subambient pressure GC‐MS in both the EI and the ammonia positive Cl modes. Considerable differences in the lipid composition of the two wool wax fractions collected were observed by TLC‐FID and GC‐MS.
Thermal behavior of fat droplets as related to adsorbed milk proteins in complex food emulsions. A DSC study
Authors: Relkin Perla , Ait‐Taleb Amel , Sourdet Stéphanie , Fosseux Pierre‐Yves 
Published: November 2006

AbstractThe thermal behavior of hydrogenated palm kernel oil‐in‐water emulsions, which differed in their milk‐protein composition, was studied in parallel with other characteristic parameters such as the aggregation/coalescence of fat droplets, and the proportion of adsorbed proteins at the oil/water interface. DSC was applied to monitor the crystallization and melting behavior of nonemulsified and emulsified fat samples. Comparison between nonemulsified and emulsified fat samples showed that in emulsified samples the initial temperature of fat crystallization and the temperature of the completion of melting were invariably lower and slightly higher, respectively. Furthermore, in complex food emulsions the supercooling temperature needed to initiate fat crystallization and the variation in its growth rate in the cooling experiment were dependent on the amount and nature of the adsorbed proteins. Our results indicate that the total replacement of milk proteins by whey proteins affected the fat crystallization behavior of emulsified fat droplets, in parallel with changes in their protein surface coverage and in their physical stability against fat droplet agglomeration.
Thermal and rheological properties of Lupinus albus flour
Authors: Xu Jingyuan , Mohamed Abdellatif A. 
Published: November 2006

AbstractThe thermal and rheological properties of lupin flour were investigated by DSC and rheometry. DSC study showed that whole and defatted lupin meal had identical thermal properties, and lupin had the same glass transition as the wheat protein gluten. By measuring the linear rheological properties of a series of concentrations of defatted lupin suspensions, we found that defatted lupin suspensions exhibited strong viscoelastic solid properties, which were to some extent similar to those of gluten. Both storage (G′) and loss (G″) moduli increased dramatically over a narrow range of lupin concentrations. The linear range of the rheological properties of lupin was very small. The stress relaxation studies showed that the lupin suspensions did not relax a decade within a thousand seconds, indicating that the molecules of lupin have strong physical interactions. This research offered new insight into physical properties of lupin and will be useful for further studies on applications for lupin.
Effects of natural antioxidants on iron‐catalyzed lipid oxidation of structured lipid‐based emulsions
Authors: Osborn Hannah T. , Akoh Casimir C. 
Published: November 2006

AbstractThe effects of iron, pH, and natural antioxidants (α‐tocopherol, gallic acid, and quercetin) on oxidation of structured lipid‐based emulsions were evaluated. Ten percent oil‐in‐water emulsions were formulated with a canola oil/caprylic acid structured lipid and stabilized with 0.5% whey protein isolate. The PV, anisidine values, and Totox values of emulsions stored at 50°C were measured over a 15‐d period. Iron significantly (P<0.05) increased lipid oxidation rates compared to control emulsions. Greater iron‐catalyzed lipid oxidation occurred in the pH 3.0 emulsions compared to their pH 7.0 counterparts. Quercetin and gallic acid exhibited significant (P<0.05) prooxidant effects on total oxidation in the pH 3.0 emulsions. Emulsions at pH 7.0 were relatively stable to oxidation throughout the storage period. Because of the ability of some of these natural antioxidants to exhibit prooxidant activity, care should be exercised when adding them to food systems containing transition metals.
Applications of immobilized Thermomyces lanuginosa lipase in interesterification
Authors: Yang Tiankui , Fruekilde Maj‐Britt , Xu Xuebing 
Published: November 2006

AbstractThe aim of this work was to investigate the catalytic functions of a new immobilized Thermomyces lanuginosa lipase in interesterification and to optimize the conditions of interesterification for the production of human milk fat substitutes (HMFS) containing n−3 PUFA by response surface methodology (RSM). Thermomyces lanuginosa lipase had an activity similar to that of immobilized Rhizomucor miehei lipase (Lipozyme RM IM) in the glycerolysis of sunflower oil, but the former had higher activity at a low reaction temperature (5°C). Thermomyces lanuginosa lipase was found to have much lower catalytic activity than Lipozyme RM IM in the acidolysis of sunflower oil with caprylic acid. However, the activity of T. lanuginosa lipase was only slightly lower than that of Lipozyme RM IM in the ester‐ester exchange between tripalmitin (PPP) and the ethyl esters of EPA and DHA (EE). For this reason, the new immobilized T. lanuginosa lipase was used to produce HMFS from PPP by interesterification with EE. The optimization of major parameters was conducted with the assistante molar ratio of 5 (EE/PPP), a lipase load of 20 wt% (on substrates), and a reaction time of 20 h, with acyl incorporation up to 42%. The model generated significantly represented real relationships between the response (incorporation) and reaction parameters.
Development and optimization of cultured goat cream butter
Authors: Rodríguez Alicia , Bunger Andrea , Castro Eduardo , Sousa Isabel , Empis Jose 
Published: November 2006

AbstractA central composite design 22+star based on response surface methodology was used for development and optimization of a cultured goat cream butter formulation (cultured). The goat milk cream was inoculated with freeze‐dried mesophilic aromatic lactic cultures and showed an increase in acidity and a aromatic lactic cultures and showed an increase in acidity and a decrease in lactose content when the concentration of lactic cultures was increased. An optimized temperature of 28°C was chosen for fast acid production in the goat milk cream. The lactic culture concentration significantly affected flavor, sensory texture, and overall quality, but the fermentation process were an inoculum dosage of 8.8 U/100 L and a fermentation time of 7 h at 28°C. This cultured formulation achieved optimal sensory quality in the attributes appearance, flavor, texture, and overall quality. At refrigerator temperature (4°C) the cultured formulation behaved as a solid and lacked spreadability, whereas it had ideal spreadability at 15°C when the solid fat content (SFC) was around 18.0%. At room temperature (18–25°C) the SFC was between 11 and 8%, respectively.
Antioxidant effect of soy lecithins on vegetable oil stability and their synergism with tocopherols
Authors: Judde Armelle , Villeneuve Pierre , Rossignol‐Castera Anne , Le Guillou Anne 
Published: November 2006

AbstractThe antioxidant effect of lecithins was tested on several oils and fats varying in FA composition and tocopherol content. Standard lecithins, when added at a level of 1% w/w, exhibited a good protective effect against oxidation. This effect was observed to depend on the phospholipid content of the tested lecithins and the FA composition of the tested oils. Better results were obtained with lecithin samples containing high proportions of PC and PE. Indeed, the main antioxidant mechanism of lecithins was due to a synergistic effect between amino‐alcohol phospholipids and γ‐ and δ‐tocopherols. No synergism was observed with α‐tocopherols, especially when the tested oil was rich in linoleic acid. Therefore, the antioxidant protection of lecithins was not effective for sunflower oil. Finally, the use of fractionated or enriched lecithins was not clearly advantageous compared to standard oil lecithins.
Electrospray ionization MS of high M.W. TAG oligomers
Authors: Byrdwell W. Craig , Neff William E. 
Published: November 2006

AbstractReported are the on‐line LC/electrospray ionization MS of large, high M.W. oligomers formed from heated triolein, a TAG used as a model for dietary oils. Triolein, the major component of olive oil, canola oil, and other dietary oils, was heated at frying temperature, and the TAG oxidation products were separated using RP‐HPLC coupled to an ion trap mass spectrometer via an electrospray ionization interface. Ammonium formate was added as a sheath liquid to promote ammonium adduct formation. Masses corresponding to ammonium adducts of intact carbon‐linked dimers (m/z 1783–1787), trimers (m/z 2666–2672), and tetramers (m/z 3547–3557) of triolein, with and without additional sites of unsaturation, were observed. Also, dimers, trimers, and tetramers containing one, two, or three additional oxygens, also with and without additional sites of unsaturation, are reported. Based on the formation of some types of triolein dimers, we believe that tristearin might also form dimers, even though it has no readily oxidizable sites of unsaturation. Oxidized tristearin monomers, tristearin dimers, chainaddition products, and chain‐shortened products are observed.
In situ alkaline transesterification: An effective method for the production of fatty acid esters from vegetable oils
Authors: Haas Michael J. , Scott Karen M. , Marmer William N. , Foglia Thomas A. 
Published: November 2006

AbstractThe production of simple alkyl FA esters by direct alkali‐catalyzed in situ transesterification of the acylglycerols (AG) in soybeans was examined. Initial experiments demonstrated that the lipid in commercially produced soy flakes was readily transesterified during agitation at 60°C in sealed containers of alcoholic NaOH. Methyl, ethyl, and isopropyl alcohols readily participated in the reaction, suggesting that the phenomenon is a general one. Statistical experimental design methods and response surface regression analysis were used to optimize reaction conditions, using methanol as alcohol. At 60°C, the highest yields of methyl ester with minimal contamination by FFA and AG were predicted at a molar ratio of methanol/AG/NaOH of 226∶1∶1.6 with an approximately 8‐h incubation. An increase in the amount of methanol, coupled with a reduced alkali concentration, also gave high ester yields with low FFA and AG contamination. The reaction also proceeded well at 23°C (room temperature), giving higher predicted ester yields than at 60°C. At room temperature, maximal esterification was predicted at a molar ratio of 543∶1∶2.0 for methanol/AG/NaOH, again in 8 h. Of the lipid in soy flakes, 95% was removed under such conditions. The amount of FAME recovered after in situ transesterification corresponded to 84% of this solubilized lipid. Given the 95% removal of lipid from the soy flakes and an 84% efficiency of conversion of this solubilized lipid to FAME, one calculates an overall transesterification efficiency of 80%. The FAME fraction contained only 0.72% (mass basis) FFA and no AG. Of the glycerol released by transesterification, 93% was located in the alcoholic ester phase and 75 was on the post‐transesterification flakes.