bluuebunny/crossref_metadata_2025_split huggingface dataset:
The analysis of sterol degradation products to detect vegetable fats in chocolate
Authors: Crews C. , Calvet‐Sarrett R. , Brereton P. 
Published: May 2007

AbstractA method for the detection of hydrocarbon sterol degradation products (sterenes) has been adapted for the analysis of noncocoa butter vegetable fats in chocolate. The method involves solvent extraction of the fat separation of the sterene fraction, and analysis of individual sterenes with mass spectrometric detection. The sterene composition of refined noncocoa vegetable fats was determined in samples of cocoa butter, and retail chocolates. The presence of known sterenes was confirmed for all of the refined vegetable fats and for a single sample of cocoa butter, the processing history of which was not known. Detection of vegetable fat added to chocolate at the 5% level was demonstrated. Sterenes were detected only in chocolates labeled as containing vegetable fats. This technique has potential use as a screening method for the detection, but not quantification, of refined vegetable fat in chocolate.
Characterization of edible oils and lard by fourier transform infrared spectroscopy. Relationships between composition and frequency of concrete bands in the fingerprint region
Authors: Guillén M. D. , Cabo N. 
Published: May 2007

AbstractFourteen samples of edible oils and lard have been studied by means of Fourier transform infrared spectroscopy. The spectra were recorded from a film of pure oil or lard between two discs of KBr. The bands of the spectra were assigned to different functional group vibrations. The frequencies of some bands have constant values, independent of the nature of the sample. However, frequencies of other bands, some of them in the fingerprint region, depend greatly on the sample composition. Equations obtained from frequency of these bands and composition data are valuable to predict the proportions of saturated, monounsaturated and polyunsaturated acyl groups in oils and lard.
Characterization of α‐ and γ‐linolenic acid oils by reversed‐phase high‐performance liquid chromatography‐atmospheric pressure chemical ionization mass spectrometry
Authors: Laakso Päivi 
Published: May 2007

AbstractTriacylglycerols of oils rich in α‐ and/or γ‐linolenic acids were analyzed by reversed‐phase high‐performance liquid chromatography (HPLC) coupled with atmospheric pressure chemical ionization mass spectrometry [(APCI)MS]. The (APCI)MS spectra of most triacylglycerols exhibited [M + H]+ and [M ‐ RCOO]+ ions, which defined the molecular weight and the molecular association of fatty acyl residues, respectively. Reversed‐phase HPLC resulted in, at least, partial separation of triacylglycerols containing α‐ and/or γ‐linolenic acid moieties. Molecules containing α‐linolenic acid residues exhibited a relatively weaker retention by the stationary phase than the corresponding molecules containing γ‐linolenic acid residues. Good separation of triacylglycerols of cloudberry seed oil, evening primrose oil, borage oil, and black‐currant seed oil was achieved. The molecular species identification of separated components was based on the (APCI)MS data as well as on the elution properties of triacylglycerols on reversed‐phase HPLC. This study demonstrated the efficiency of HPLC‐(APCI)MS in determining the molecular species compositions of triacylglycerols in complex natural mixtures. Good quality mass spectra could be extracted even from minor chromatographic peaks representing 0.2% or less of the total triacylglycerols.
Antioxidant activity of green teas in different lipid systems
Authors: Frankel Edwin N. , Huang Shu‐Wen , Aeschbach Robert 
Published: May 2007

AbstractDifferent commercial green teas from Japan, China, and India, were compared in different lipid systems. Green teas were active antioxidants in bulk corn oil oxidized at 50°C but were prooxidant in the corresponding oil‐in‐water emulsions. Green teas also were active antioxidants in soybean lecithin liposomes oxidized at 37°C in the presence of cupric acetate as catalyst. At 50°C, however, three of the samples of green tea were active antioxidants in the absence of copper catalyst, and two samples showed prooxidant activity in the presence of copper catalyst. The marked variation in activity among green tea samples may be due partly to differences in their relative partition between phases in different lipid systems. The improved antioxidant activity observed for green teas in lecithin liposomes compared to corn oil emulsions can be explained by the greater affinity of the polar tea catechin gallates for the polar surface of the lecithin bilayers, thus affording better protection against oxidation. Liposomes may thus be appropriate lipid models to evaluate antioxidants for foods containing phospholipids.
Frying quality and oxidative stability of high‐oleic corn oils
Authors: Warner K. , Knowlton S. 
Published: May 2007

AbstractTo determine the frying stability of corn oils that are genetically modified to contain 65% oleic acid, high‐oleic corn oil was evaluated in room odor tests and by total polar compound analysis. Flavor characteristics of french‐fried potatoes, prepared in the oil, were also evaluated by trained analytical sensory panelists. In comparison to normal corn oil, hydrogenated corn oil and high‐oleic (80 and 90%) sunflower oils, high‐oleic corn oil had significantly (P<0.05) lower total polar compound levels after 20 h of oil heating and frying at 190°C than the other oils. Fried‐food flavor intensity was significantly higher in the normal corn oil during the early portion of the frying schedule than in any of the high‐oleic or hydrogenated oils; however, after 17.5 h of frying, the potatoes fried in normal corn oil had the lowest intensity of fried‐food flavor. Corn oil also had the highest intensities of off‐odors, including acrid and burnt, in room odor tests. High‐oleic corn oil also was evaluated as a salad oil for flavor characteristics and oxidative stability. Results showed that dry‐milled high‐oleic corn oil had good initial flavor quality and was significantly (P<0.05) more stable than dry‐milled normal corn oil after oven storage tests at 60°C, as evaluated by flavor scores and peroxide values. Although the high‐oleic corn oil had significantly (P<0.05) better flavor and oxidative stability than corn oil after aging at 60°C, even more pronounced effects were found in high‐temperature frying tests, suggesting the advantages of high‐oleic corn oil compared to normal or hydrogenated corn oils.
A kinetic study on the autoxidation of sunflowerseed oil
Authors: Topallar Hüseyin , Bayrak Yüksel , Işcan Mehmet 
Published: May 2007

AbstractUnhydrogenated and hydrogenated sunflowerseed oils were exposed to the autoxidation process by sunlight under atmospheric conditions. Experiments were carried out in equal‐sized glass, PET (polyethylene terephthalate) polymer, and metal (covered by tin) containers. The reaction time was 30 d, and the reaction course was observed by determining weight changes and peroxide values (PV) of the oil samples at the same time within 2‐d intervals. The logarithm of the PV was plotted against time, and straight lines were obtained from the 4th or 6th d. The autoxidation reaction constants were obtained for each oil in each container. When comparing the reaction constants, the unhydrogenated oils autoxidize easily, and the autoxidation reaction occurs faster in sunlight in glass than in the PET polymer container and much faster than in the darkness of the metal container.
Oxidative stability and nuclear magnetic resonance analyses of linoleic acid encapsulated in cyclodextrins
Authors: Reichenbach Wendy A. , Min David B. 
Published: May 2007

AbstractThe effects of α‐ and β‐cyclodextrin (CD) on the oxidative stability of linoleic acid (LA) at 35°C were studied by measuring headspace oxygen depletion in airtight 35‐mL serum bottles. LA was encapsulated in α‐CD or β‐CD in an aqueous solution during homogenization at 8000 rpm for 1 min and then dried under vacuum for 60 h at room temperature. Headspace oxygen was measured by thermal conductivity gas chromatography. The rate of oxygen depletion for the control, which contained LA only, was 93.8 µmole/L·h. The rates of oxygen depletion for LA, encapsulated at a 1:1 mole ratio (mole CD/moles LA) in α‐CD and β‐CD, were 13.8 and 111 µmoles/L·h, respectively. When LA was encapsulated in α‐CD and β‐CD at a 2:1 mole ratio (moles CD/moles LA), the rates of oxygen depletion were 0.573 and 53.9 µmoles/L·h, respectively. Although α‐CD protected LA from reaction with oxygen at both ratios, the rate of oxygen depletion by LA encapsulated in β‐CD at a 1:1 mole ratio was not statistically different from the control. β‐CD protected LA from reaction with oxygen at a 2:1 mole ratio. 1H nuclear magnetic resonance spectra of the complexes formed from 1:1 mole ratios of LA and CD indicated that LA was encapsulated in α‐CD or β‐CD.
13C nuclear magnetic resonance spectral confirmation of Δ6‐and Δ7‐trans‐18:1 fatty acid methyl ester positional isomers
Authors: Mazzola E. P. , McMahon J. B. , McDonald R. E. , Yurawecz M. P. , Sehat N. , Mossoba M. M. 
Published: May 2007

AbstractTrans octadecenoic acid methyl ester isomers were obtained from a partially hydrognated soybean oil and isolated by silver‐ion high‐performance liquid chromatography. Recently, the double‐bond positions for nine individual trans octadecenoic acid positional isomers (Δ8 through Δ16) were confirmed by gas chromatography‐electron ionization mass spectrometry after derivatization to 2‐alkenyl‐4,4‐dimethyloxazoline. In this communication, the presence of two additional trans‐18:1 fatty acid methyl ester positional isomers (Δ6 and Δ7) in the same mixture is confirmed by 13C nuclear magnetic resonance spectroscopy. The identity of the Δ5‐trans‐18:1 fatty acid methyl ester positional isomer is inferred.
Practical limitations in determining vegetable oil acid values by a novel pH‐metric method
Authors: Berezin O. Yu , Tur’yan Ya I. , Kogan L. , Kuselman I. , Shenhar A. 
Published: May 2007

AbstractA novel pH‐metric method is described for the determination of acid values (AV) in vegetable oils without titration. The method is based on a reagent containing triethanolamine, isopropanol, and water to which an oil sample is added before measuring pH. Oil samples with AV in the range 0.006–0.107 mg KOH/g oil were prepared from commercial soybean oil by treatment with a strong‐base anion exchanger in OH− form and addition of oleic acid. Compared to the standard titrimetric method, significantly greater AV were obtained at less then 0.02 mg KOH/g oil. This was due to the influence of triethanolamine hydrolysis on the acid‐base equilibrium in the mixture “oil‐reagent.” Thus, the AV 0.02 mg KOH/g oil is accepted as the limit of quantitation. Because refined oils usually have AV of 0.05 mg KOH/g oil or more, this method should be suitable for practical oil analyses.
Explorative spectrometric evaluations of frying oil deterioration
Authors: Engelsen Søren Balling 
Published: May 2007

AbstractThe potential of spectroscopy as a reliable and fast method for determining the deterioration of frying oils was investigated. Daily oil samples were collected from a commercial Chinese spring roll plant. The plant was operated one shift, 5 d a week, then cleaned and restarted with fresh oil every 4 wk. Each oil sample was analyzed by 11 chemical/physical methods and fluorescence, near infrared/visible (NIR/VIS), Fourier transform infrared (FT‐IR) and FT‐Raman spectroscopic procedures. The results were evaluated and compared by principal‐component analysis and partial least squares regression. Most chemical/physical and all spectroscopic methods detected the deterioration during the first half of the frying cycle. Thereafter, an equilibrium occurred between deterioration processes and replenishment with new oil. At equilibrium, the correlation between frying time and the various methods was nonlinear. FT‐IR with the attenuated total reflectance sampling technique was the most direct and accurate method of monitoring gross changes in the frying oil. Fluorescence was the technique that provided the best models for anisidine value, oligomers, iodine value, and vitamin E. NIR/VIS spectroscopy proved to be a good general‐purpose technique. The study demonstrated that spectroscopic sensors have the potential to replace titration and chromatographic procedures, and can be used in combination with chemometric data analysis to optimize deep‐frying operations.
Thermoxidation of substrate models and their behavior during hydrolysis by porcine pancreatic lipase
Authors: Arroyo Ruth , Sánchez‐Muniz Francisco J. , Cuesta Carmen , Sinisterra José V. , Sánchez‐Montero José M. 
Published: May 2007

AbstractThe behavior of thermoxidized triacylglycerols during hydrolysis catalyzed by porcine pancreatic lipase was evaluated using nonpolar triacylglycerols isolated from palm olein (NPTPO), triolein, and sn‐1,3 diolein substrates. Substrates were thermoxidized at 180°C for 1 to 4 h. Owing to formation of polymers and dimers of triacylglycerols, the molecular weight of the thermoxidized substrates increased. After 1 h heating, the concentration of polymers and dimers was similar for the sn‐1‐3 diolein and triolein samples but higher in NPTPO samples. Conjugated double bonds were formed in all samples, and α,β‐unsaturated carbonyl compounds developed through allylic oxidations. These caused increased ultraviolet absorbance at 232 nm. The hydrolysis of heated and unheated samples by the lipase can be described by a Michaelian equation. The enzyme showed a higher apparent Vmax and KMwith heated sn‐1,3 diolein and triolein than with their unheated counterparts. This was due to the generation of polar compounds which acted as emulsifiers and which favored the formation of an oil/water microemulsion. This behavior was not observed in NPTPO, where heating decreased the apparent Vmax and KMover the first 2 h. Later, a tendency to increase these values was observed. The results could be explained by a balance between concentration of surfactants and of natural emulsifiers in the thermoxidized samples.
Supercritical fluid extraction of lipids from deep‐fried food products
Authors: Devineni N. , Mallikarjunan P. , Chinnan M. S. , Phillips R. D. 
Published: May 2007

AbstractA supercritical fluid extraction (SFE) method is described for extracting lipids from fried‐food samples. Response surface analysis was used to study the effects of variables, including pressure, temperature, flow rate, and modifier (methanol) on lipid extraction by SFE. The analysis of variance for the response variables indicated that the models developed were satisfactory with coefficients of determination of 0.95 and 0.92 for chicken nuggets and potato fries, respectively. The models predicted that increasing the pressure increased the percentage lipid extracted for both chicken nuggets and potato fries. In addition, the pressure by temperature interactions were significant for chicken nuggets and potato fries. Slight differences in fatty acid composition were observed between SFE and the Goldfisch method. The SF extracts contained traces of C12:0, C20:0, and C24:0 in chicken nuggets and C14:1, C18:3, C22:0, and C23:0 in potato fries, respectively, which are not found in the Goldfisch extracts. The optimal conditions for extraction are: 53 MPa, 150°C, 4 mL/min, and 10% modifier for chicken nuggets and 53 MPa, 150°C, 3 mL/min, and 0% modifier for potato fries. To duplicate the results of exhaustive Goldfisch extraction with petroleum ether, SFE conditions of 44 MPa, 80°C, 3 mL/min, and 0% modifier were used to produce similar results for both chicken nuggets and potato fries.
Anchovy oil thermal polymerization kinetics
Authors: Guner F. Seniha 
Published: May 2007

AbstractThe thermal polymerization reaction kinetics of anchovy oil was investigated with and without catalyst. In order to make a comparison, linseed oil was included in the study. Reactions were carried out 260, 270, and 280°C, and a kinetic model was determined for each case. The reactions for linseed oil with and without catalyst at all temperatures followed the first‐order kinetics. In the case of anchovy oil, the best‐fitted straight line is obtained by plotting viscosity values against time, and the reaction proceeds in two stages at 280°C without catalyst. The use of catalyst lowered the temperature to 270°C for the appearance of two different rates. Additionally, some mathematical equations were derived between iodine value, refractive index, viscosity, and reaction time.
Antioxidant activity and active sites of phospholipids as antioxidants
Authors: Saito Hiroaki , Ishihara Kenji 
Published: May 2007

AbstractVarious compounds, representative of the major functional groups in phospholipids, phosphatidylethanolamine and phosphatidylcholine, were tested for antioxidant activity (AA) in a sardine oil system to determine the relationship between molecular structure and the AA of these compounds. AA was found to be attributable not only to the side‐chain amino groups but also to the cooperative effect of the hydroxy group in the side chain. Choline and ethanolamine, side‐chain moieties of phospholipids, strongly inhibited increases in peroxide values in a sardine oil mixture during storage; however, phosphatidic acid derivatives and glycerol, also major functional groups of phospholipids, did not show AA. Choline and ethanolamine have hydroxy amines as functional groups; therefore, several model reagents that contained amines and alcohols were assayed to compare the activity of the amino group with that of the hydroxy group. All basic alkylamines examined had AA as decomposers of hydroperoxides. The intramolecular hydroxy group in these amines complemented AA of the amino group. Only intramolecular alcohol, which can donate a proton, showed strong synergistic activity with AAof the basic amines, while protected groups, such as methyl ether and phosphate ester, did not show this effect.
Blending process optimization into special fat formulation by neural networks
Authors: Block J. M. , Barrera‐Arellano D. , Figueiredo M. F. , Gomide F. A. C. 
Published: May 2007

AbstractComputer programs are used to manage, supervise, and operate production lines of oil, margarine, butter, and mayonnaise in the fats and oils industry. Automation allows for lower‐cost and better‐quality products. The present paper shows a multilayer perceptron‐type, second‐generation neural network that was built based on a desirable product solid profile and was designed to formulate fats from three ingredients (one refined oil and two hydrogenated soybean‐based stocks). This network operates with three sequential decision levels, technical, availability and costs, to furnish up to nine possible formulations for the desired product. Upgrading verification was accomplished by soliciting to the formulation network all 63 products used in the upgrading (the answers were evaluated by a panel of experts and considered satisfactory) and 17 commercial products. It was possible to formulate more than 50% of the products in the network with only the three bases available. The results demonstrate the possibility of using neural networks as an alternative to the automation process for the special fats formulation process.
Enzymatic hydrolysis in conjunction with conventional pretreatments to soybean for enhanced oil availability and recovery
Authors: Shankar Devesh , Agrawal Y. C. , Sarkar B. C. , Singh B. P. N. 
Published: May 2007

AbstractEnzymatic hydrolysis of oilseeds prior to extraction has recently been shown to enhance the extractable oil in oilseeds and its recovery. This paper presents the results of optimizing the combination of enzymatic hydrolysis with one or more conventional pretreatments to soybean and of optimizing the hydrolysis parameters as they determine the mechanical extractability as well as the solvent extractability. Enzymatic hydrolysis in conjunction with flaking (dehulling inherent) and steam conditioning offered statistically the best pretreament combination for soybean at a 5% level of significance, enhancing the extractable oil content by about 4.8% of moisture‐free sample. The optimal hydrolysis parameter values based on response surface analysis were: hydrolysis moisture content 23.22% wet basis, enzyme concentration 11.99 vol/wt, and incubation period 13.79 h. Over 99% of the total extractable oil released after hydrolysis was extractable within 16 h on a Soxhlet extractor.
Soy hull carbon as adsorbents of crude soy oil components: Effect of carbonization time
Authors: Proctor A. , Gnanasambandam Ravin 
Published: May 2007

AbstractStudies were conducted to evaluate the performance of soy hull carbon adsorbents as affected by carbonization time. Carbonization was done by heating soy hulls to 400°C for up to 30 min. Increased carbonization time resulted in elevated surface pH and titratable alkalinity. The effectiveness of adsorbents in binding minor soy oil components was studied. Free fatty acids content was decreased 70% with adsorbents carbonized for 30 min. Peroxides were adsorbed, but increasing carbonization time did not alter absorption by carbons. A similar trend was observed with the adsorption of total phospholipids. The residual lutein content of crude soy oil was not affected by the adsorbents. X‐ray diffraction studies showed that carbonization at 400°C converted the polysaccharide‐based structure of soy hull to an amorphous, highly disorganized, random structure. Increase in carbonization time resulted in broadening of the diffraction pattern between 5 and 25° 2ϑ. Infrared spectra of soy carbon samples revealed presence of asymmetric C‐H stretch, symmetric C‐H bends, and C=O groups. The intensities of these spectra decreased with time of carbonization.
Triacylglycerols responsible for the onset of nucleation during clouding of palm olein
Authors: Sulaiman Mohd Zaki , Sulaiman Nik Meriam , Kanagaratnam Sivaruby 
Published: May 2007

AbstractThis paper discusses the results of an investigation to identify triacylglycerols that induce clouding of refined bleached deodorized (RBD) palm olein, which occurred within 24 h after fractionation. The experiments were conducted in a jacketed glass vessel in which the liquid sample was cooled from 70 to 23°C at a predetermined rate. Clouding began at around 28.5°C. The presence of three different types of saturated triglycerides, namely tripalmitin, dipalmitoyl‐myristoylglycerol and dipalmitoyl‐stearoyl‐rac‐glycerol, is critical in the formation of nuclei and thus clouding of the RBD palm olein. This conclusion is based on the significant increase in the relative concentration of these components in the nuclei as compared to the mother oil.
Physical properties of liquid edible oils
Authors: Coupland John N. , McClements D. Julian 
Published: May 2007

AbstractLiterature values of density, viscosity, adiabatic expansion coefficient, thermal conductivity, specific heat (constant pressure), ultrasonic velocity, and ultrasonic attenuation coefficient are compiled for a range of food oils and water at 20°C, and a series of empirical equations are suggested to calculate the temperature dependency of these parameters. The importance of these data to the application of ultrasonic particle‐sizing instruments to food emulsions is discussed.