bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of hydrophobic emulsifier additives on crystallization behavior of palm mid fraction in oil‐in‐water emulsion
Authors: Awad Tarek , Sato Kiyotaka 
Published: November 2006

AbstractUltrasonic velocity measurements and X‐ray diffraction were employed to monitor the crystallization behavior of palm mid fraction (PMF) in oil‐in‐water emulsions (20 vol%). Three hydrophobic emulsifiers—sucrose oligoesters (SOE) containing palmitic acid (P‐170) and stearic acid (S‐170) moieties and a polyglycerine ester (DAS‐750) containing a stearic acid moiety—were added to PMF in an attempt to increase the rate and extent of crystallization of PMF, which are otherwise suppressed owing to emulsification of the oil phase into many droplets. The results revealed that the hydrophobic emulsifiers accelerate the nucleation of PMF in the emulsion system, while retarding the rate of crystal growth. As a results, the crystallization temperature (Tc) of PMF increased with increasing concentrations of the hydrophobic emulsifiers. The effects of the three additives were different; in particular the addition of DAS‐750 remarkably enhanced crystallization at low concentrations. By adding the emulsifiers at higher concentrations, the polymorphic behavior of PMF crystallization was also modified to different degrees, depending on the type of emulsifier. With addition of SOE, PMF crystallized predominantly in the β′ form; with addition of DAS‐750, the extent of β′ nucleation was reduced by comparison with that observed with SOE. The results were explained in terms of adsorption of the hydrophobic emulsifier additives at the oil‐water interface, which provides a template for acceleration of surface heterogeneous nucleation of PMF in the emulsion system.
Preparation, characterization, and surface and biological properties of N‐stearoyl amino acids
Authors: Sivasamy A. , Krishnaveni M. , Rao P. G. 
Published: November 2006

AbstractSeveral lipoamino acids were synthesized, in which n‐octadecanoic acid (stearic acid) was coupled with the α‐amino group of an amino acid. The products were characterized and their identities confirmed by advanced analytical techniques like Fourier transform infrared 1H nuclear magnentic resonance spectroscopy, and differential scanning, calorimetry. Their surface properties, such as critical micelle concentration (CMC) and foaming properties, biodegradability, and antimicrobial activity were also evaluated. The N‐stearoyl amino acids (NSA) had low CMC values, and some of them showed good foaming properties. They were screened for antimicrobial activity against the gram‐positive bacteria Staphylococcus aureus, Micrococcus luteus, and Bacillus cerceus, the gram‐negative bacteria Escherichia coli and Pseudomonas aeruginosa, and the yeast Candida albicans. All the compounds inhibited at least one of these organisms. N‐Stearoyl proline was the most effective, the order of antimicrobial activity being aromatic NSA> acidic NSA>basic NSA. However, the effective inhibition by all the compounds indicates the desirability of more thorough investigation and suggests that some of these compounds may have potential utility as biostatic additives in commercial products. All NSA are highly biodegradable and can readily be removed under conditions of normal secondary sewage treatment.
Effect of row space and irrigation on seed composition of Turkish sesame (Sesamum indicum L.)
Authors: Alpaslan M. , Boydak E. , Hayta M. , Gerçek S. , Simsek M. 
Published: November 2006

AbstractThe effect of row space (RS) and irrigation (IR) on total protein, total oil, and fatty acid composition of Harran‐grown sesame seed was studied. Total oil content of sesame varied from 46.4 to 51.5%. The oil and protein contents were significantly different among treatments (P<0.01) in 1998 and 1999. IR affected oil content significantly (P<0.01) in both years, and RS had no significant effect. The protein content was significantly influenced by RS and IR at P<0.05 and P<0.01, respectively. RS 70 cm had the highest protein content followed by RS 60, 50, and 40 cm, respectively. IR every 24th day resulted in the highest level of protein, followed by 18th‐, 12th‐, and 6th‐day irrigation, respectively. Correlation coefficients between protein and oil content were −0.34 in 1998 and −0.59 in 1999. RS (P<0.05) and IR (P<0.01) influenced oleic and linoleic acid contents significantly. Interactions of RS and IR were also found to be significant (P<0.05) over the oleic and linoleic acid levels.
Gas chromatographic analysis of diels‐alder adducts of geometrical and positional isomers of conjugated linoleic acid
Authors: Reaney Martin J. T. , Liu Ya‐Dong , Taylor Wesley G. 
Published: November 2006

AbstractThis research demonstrates the gas chromatographic analysis of the 4‐methyl‐1,2,4‐triazoline‐3,5‐dione (MTAD) adducts derived from standards of cis,trans‐9,11‐octadecadienoic acid, trans,trans‐9,11‐octadecadienoic acid, and cis,cis‐9,11‐octadecadienoic acid. Methyl cis,trans‐9,11‐octadecadienoate and methyl trans,trans‐9,11‐octadecadienoate formed Diels‐Alder addition products with MTAD to produce adducts with similar mass spectral fragmentation patterns but different retention times determined by gas chromatography/ mass spectrometry. Methyl cis,cis‐9,11‐octadecadienoate reacted slowly and produced two adducts with similar fragmentation patterns and different retention times. These results were comparable to those reported for an analogous series of conjugated hexadienes. Based on hexadiene reactions, methyl cis,trans‐9,11‐octadecadienoate produced a trans adduct as a major product while methyl trans,trans‐9,11‐octadecadienoate formed a cis adduct. Methyl cis,cis‐9,11‐octadecadienoate reacted slowly under the conditions used leaving mostly unreacted material. Of the adducts observed from this isomer, a major trans adduct and a minor cis adduct were formed.
Application of arrhenius kinetics to evaluate oxidative stability in vegetable oils by isothermal differential scanning calorimetry
Authors: Tan C. P. , Che Man Y. B. , Selamat J. , Yusoff M. S. A. 
Published: November 2006

AbstractIn this study, 10 different vegetable oils were oxidized at four different isothermal temperatures (383, 393, 403, and 413 K) in a differential scanning calorimeter (DSC). The protocol involved oxidizing vegetable oils in a DSC cell with oxygen flow. A rapid increase in evolved heat was observed with an exothermic heat flow appearing during initiation of the oxidation reaction. From this resulting exotherm, the onset of oxidation time (To) was determined graphically by the DSC instrument. In our experimental data, linear relationships were determined by extrapolation of the log (To) against isothermal temperature. The rates of lipid oxidation were highly correlated with temperature. In addition, based on the Arrhenius equation and activated complex theory, reaction rate constants (k), activation energies (Ea), activation enthalpies (ΔH‡), and activation entropies (ΔS‡) for oxidative stability of vegetable oils were calculated. The Ea′, ΔH‡, and ΔS‡ for all vegetable oils ranged from 79 to −104 kJ mol−1, from 76 to −101 kJ mol−1, and from −99 to −20 J K−1 mol−1, respectively. Based on the results obtained, differential scanning calorimetry appears to be a useful new instrumental method for kinetic analysis of lipid oxidation in vegetable oil.
Improved oil treatment conditions for soft degumming
Authors: Choukri A. , Kinany M. A. , Gibon V. , Tirtiaux A. , Jamil S. 
Published: November 2006

Abstract“Soft degumming” is a new physicochemical degumming process. It involves the complete elimination of phospholipids by using a chelating agent, EDTA, in the prescence of an emulsifying additive. To study the optimal cost of the process, a laboratory study was undertaken to find a method based on substituting the emulsifying additive by endogenous phospholipids. The phospholipids were first extracted from the oil by an initial hot‐water treatment. In a second stage, a solution containing a chelating agent was incorporated. The mixture was then vigorously stirred to form an emulsion. The degummed oil was obtained after centrifugation. A comparative study carried out on several oils provided an indication of the efficiency of this alternative procedure. The phospholipid content of the processed oils was about 5 ppm phosphorus.
Fatty acid composition of spanish shortenings with special emphasis on trans unsaturation content as determined by fourier transform infrared spectroscopy and gas chromatography
Authors: Alonso L. , Fraga M. J. , Juárez M. , Carmona P. 
Published: November 2006

AbstractA Fourier transform infrared spectroscopic procedure was used to analyze 34 edible fats (22 shortenings and 12 vegetable margarines) as neat fats (IRNF) to determine their total trans fatty acid (TFA) content. The sloping baseline was corrected with a reference spectrum based on a nonprocessed olive oil. The calibration was done using seven partially hydrogenated fats with an individual TFA content previously determined by the combination of gas chromatography (GC) with argentation thin‐layer chromatography. Taking into account the different absorptivities of various trans isomers, different correction factors were calculated using the calibration standards (0.83 and 1.71 for single trans bonds in both diethylene and triethylene and for trans, trans‐diethylene fatty acids, respectively) and applied to calculate the total TFA of samples. Moreover, the samples were converted to their methyl esters and reanalyzed following the same procedure (IRFAME). Differences in TFA content of fats were not found when a t‐test was used to compare the results obtained by IRNF vs. either IRFAME or GC, suggesting that IR of neat fats could be used, thus avoiding the need to prepare sample solutions in organic solvents and to prepare fatty acid methyl esters. The mean TFA content (determined by IRNF) of a representative group of Spanish shortenings (22 samples) that varied widely in terms of fat sources, processes, and purposes (bakery, sandwiches, ice cream, coatings, chocolate coverings) was 6.55±11.40%, although more than 54% contained <3% of TFA. Fatty acid composition of shortenings by direct GC using a 100‐m polar cyanopolysiloxane capillary column indicated that the mean trans‐18∶2 isomer content was 0.58%, ranging from 0.9 to 3.4%. Small amounts of trans‐18∶3 isomers (<0.3%) were observed in 18 of the 22 shortenings studied; the maximal value was <2%. The mean value of the fraction saturated+TFA of shortenings was high (59.95±12.73%), including two values higher than 83%.
Milled rice surface lipid measurement by diffuse reflectance fourier transform infrared spectroscopy (DRIFTS)
Authors: Gangidi Rahul Reddy , Proctor Andrew , Meullenet Jean‐François 
Published: November 2006

AbstractDiffuse reflectance Fourier transform infrared spectroscopy was investigated as a method for rice surface lipid determination. Long‐ and medium‐grain rice was milled at four degrees of milling to obtain samples with various levels of residual bran, and total lipids were determined by solvent extraction. Fourier transform infrared spectra were collected between 4000 and 400 cm−1. Weighted regression analysis identified changes in surface chemical functional groups with bran removal. Groups typical of lipids increased with bran content whereas those typical of carbohydrates and protein decreased. Partial least squares (PLS) regression analysis showed a high degree of correlation between the spectra in the 4000–400 cm−1 range and extracted lipids of long‐grain rice (R2=0.96) and medium‐grain rice (R2=0.96); a high degree of correlation was also observed when long‐ and medium‐grain rice data were combined (R2=0.96). There was a high positive correlation between the spectra and extracted lipids in the 1300–1000 cm−1 range for the long‐grain rice (R2=0.98), medium‐grain rice (R2=0.98), and combined long‐/medium‐grain rice data (R2=0.94). PLS selected spectral regions that correlated positively with functional groups of lipid/lipid oxidation products and negatively with functional groups of protein and carbohydrates.
The effect of fatty acid composition on the acrylation kinetics of epoxidized triacylglycerols
Authors: Scala John La , Wool Richard P. 
Published: November 2006

AbstractEpoxidized oils, epoxidized triacylglycerols, and epoxidized fatty acid methyl esters were made by reaction with performic acid formed in situ. The extent of epoxidation was ca. 95% for all of the epoxidized samples, as determined by 1H nuclear magnetic resonance. The epoxidized samples were reacted with an excess of acrylic acid for different reaction times. The acrylation reaction was found to have a first‐order dependence on the epoxide concentration for all oils, pure triacylglycerols, and fatty acid methyl esters. However, the rate constant of acrylation was found to depend on the composition of the epoxidized material. The acrylation rate constant for 9,10‐epoxystearic acid was 96 L2/(mol2·min). The rate constant of acrylation for the epoxides on 9,10,12,13‐diepoxystearic acid was 60 L2/(mol2·min). The acrylation rate constant for the epoxides on 9,10,12,13,15,16‐triepoxystearic acid was 50 L2/(mol2·min). Thus, the rate constant of acrylation increased as the number of epoxides per fotty acid decreased. Multiple epoxides per fatty acid decrease the reactivity of the epoxides because of steric hindrance effects, and the oxonium ion, formed as an intermediate during the epoxyacrylic acid reaction, is stabilized by local epoxide groups. These results were used to derive an acrylation kinetic model that predicts rate constants from fatty acid distributions in the oil. The predictions of the model closely match the experimentally determined rate constants.
The effects of intercepted solar radiation on sunflower (Helianthus annuus L.) seed composition from different head positions
Authors: Santalla E. M. , Dosio G. A. A. , Nolasco S. M. , Aguirrezábal L. A. N. 
Published: November 2006

AbstractThe effect of intercepted solar radiation during fruit filling on seed weight and oil content from seeds of three sectors of the head in two sunflower (Helianthus annuus L.) hybrids of low and high potential oil percentage was investigated. Seed weight in each sector depended on both the level of radiation intercepted (modified by shading and thinning plants) and the genotype grown. A higher level of intercepted solar radiation increased seed weight in each sector. Central seeds of shaded plants showed the lowest weight. The seed and kernel oil content hierarchy among the three sectors was modified only in the hybrid with high potential oil content. For each head sector, variations in seed oil content associated with changes in the level of intercepted radiation could be accounted for by changes in the kernel oil content, not in the kernel/seed ratio. Significant relationships were found between seed oil and kernel oil contents when analyses between treatments (R>0.86) and sectors (R>0.92) were carried out. These relationships together with the growing conditions of plants during seed filling, the genotype, and the seed position on the head are essential factors that should be taken into account when selecting seeds in sunflower breeding programs since they affect the commercial/industrial quality of seeds.
A kinetic study of oil deterioration during frying and a comparison with heating
Authors: Houhoula Dimitra P. , Oreopoulou Vassiliki , Tzia Constantina 
Published: November 2006

AbstractThe thermooxidative alterations of cottonseed oil during frying of potato chips without oil turnover, in a temperature range of 155–195°C, were studied. The results showed that the content of polar compounds, conjugated dienes, conjugated trienes, and p‐anisidine value (p‐AV) increased linearly with the time of frying at a rate depending on temperature. The rate constants showed a significant but low increase with temperature, except for the rate constant of conjugated trienes that was not correlated to frying temperature. The alterations induced by heating the oil were also measured and compared with those observed in frying at the same temperature. The major difference observed between frying and heating was related to the p‐AV increase, which presented a considerably higher rate during heating. The FA content, as a function of process time during frying at 185°C, showed a significant increase in palmitic acid (C16∶0) and a significant decrease in linoleic acid (C18∶2). Oleic acid (C18∶1) also showed a small but significant decrease. The same results were obtained for the oil heated at 185°C. Examination of p‐AV or conjugated dienes with polar compounds showed that both p‐AV and conjugated dienes had a linear relationship with total polar compounds, with correlation coefficients of 0.946 and 0.862, respectively.
Influence of moisture content and cooking on screw pressing of crambe seed
Authors: Singh K. K. , Wiesenborn D. P. , Tostenson K. , Kangas N. 
Published: November 2006

AbstractThe cooking and drying conditions for oilseeds preparatory to screw pressing are some of the most important factors that influence screw‐press performance. Screw‐press oil recovery, residual oil, pressing rate, and oil sediment content were measured for uncooked crambe seed and crambe seed cooked at 100°C for 10 min, pressed at six moisture contents ranging from 9.2 to 3.6% dry basis. Oil recovery significantly increased (P≤0.01) from 69 to 80.9% and 67.7 to 78.9% for cooked and uncooked seeds, respectively, as moisture content decreased. Residual oil significantly decreased (P≤0.01) from 16.3 to 11.1% and 16.9 to 11.9%, respectively, as moisture content decreased. The reduced oil loss due to only drying the seed from 9.2 to 3.6% was 32% for cooked seed, whereas cooking contributed only 3.6 to 7% reduced oil loss. Pressing rate decreased from 5.81 to 5.17 kg/h and 6.09 to 5.19 kg/h for cooked and uncooked seeds, respectively, whereas sediment content increased from 0.9 to 7.8% and 1.1 to 5.4%, respectively, as moisture content decreased. The effects of moisture content on pressing rate and sediment content were significant at P≤0.05. All relationships of screw‐press performance to moisture content were fitted to a second‐order polynomial.
Rheological characterization of egg yolk processed by spray‐drying and lipid‐cholesterol extraction with carbon dioxide
Authors: Miranda J. , Partal P. , Cordobes F. , Guerrero A. 
Published: November 2006

AbstractThe present work studies the rheological properties of avian egg yolks processed by spray‐drying and by lipid‐cholesterol extraction with CO2 under near‐critical conditions. The results have been compared with those obtained from native egg products in order to analyze the effect of processing on the microstructure and rheological properties of egg yolks. The rheological study included linear viscoelasticity measurements by means of dynamic oscillatory shear and creep tests, which provided information about the unperturbed structure of the material, as well as steady‐state flow measurements. The thermal denaturation of proteins, which was produced during the spray‐drying of egg yolk, was responsible for the dramatic change from fluid to gel‐like behavior. The thermal denaturation of proteins promotes the formation of a gel‐like network, which may be attributed to exposure of internal hydrophobic groups that favor protein aggregation. Lipid (and cholesterol) extraction from yolk increased the viscoelasticity functions and flow properties due to the increased protein concentration.
Effect of synthetic antioxidants on cholesterol stability during the thermal‐induced oxidation of a polyunsaturated vegetable oil
Authors: Valenzuela Alfonso , Sanhueza Julio , Nieto Susana 
Published: November 2006

AbstractAs a molecule with an unsaturated bond, cholesterol is prone to oxidation. Cholesterol oxidation products (COP) are found in many common foods and have been shown to be atherogenic, cytotoxic, mutagenic, and possibly carcinogenic. Efforts to reduce the formation of oxidation products are considered important during the manufacture and processing of foods. The effect of synthetic antioxidants on cholesterol oxidation has not been extensively studied. We assayed the effect of five commonly used antioxidants—BHT, BHA, the n‐propyl ester of 3,4,5‐trihydroxy benzoic acid (PG), TBHQ, and 6‐ethoxy‐1,2‐dihydro‐2,4‐trimethylquinoline (EQ)—on cholesterol stability when oxidation is induced in a Rancimat 679 instrument by bubbling air through the sample at 150°C. The sample consisted of 200 mg cholesterol dispersed in 100 g of a polyunsaturated vegetable oil (soybean oil). Formation of six COP was measured at the induction period, and at the 50 and 100 μS conductivity values. Under the experimental conditions, BHT and TBHQ were the most effective inhibitors of cholesterol oxidation. BHA and EQ were less effective, and PG was unable to prevent cholesterol oxidation. Synthetic antioxidants were more effective in preventing COP formation at the nucleus of the cholesterol structure than at the lateral chain.
Phenolic acids of borage (Borago officinalis L.) and evening primrose (Oenothera biennis L.)
Authors: Zadernowski R. , Naczk M. , Nowak‐Polakowska H. 
Published: November 2006

AbstractThe composition of phenolic acids, both free and liberated from esters and glycosides, was determined in evening primrose and borage seeds by GC and MS. The free phenolic acid fraction was predominant in these seeds. Protocatechuic acid was the principal phenolic acid of the free and esterified phenolic acids in evening primrose seeds. Ferulic acid represented a high proportion of the free phenolic acids, but hydroxycaffeic acid was the major constituent of phenolic acids liberated from esters of borage seeds.
Use of nitrogen to improve stability of virgin olive oil during storage
Authors: Di Giovacchino L. , Mucciarella M. R. , Costantini N. , Ferrante M. L. , Surricchio G. 
Published: November 2006

AbstractExperiments were carried out to study the possibility of improving the stability of extra virgin olive oil by using nitrogen as a conditioner gas during storage. With this aim, virgin olive oil samples, obtained from Leccino and Coratina cultivars, were stored in the dark, in closed bottles conditioned with air or nitrogen at 12–20 and 40°C. Results indicated that the FFA percentage increased over 1% only when oils were stored at 40°C. The PV and the K232 value (light absorbance at 232 nm) of oils increased over the limit value allowed by European Union law when the bottles were only partly filled and air was the conditioner gas. The use of nitrogen as conditioner gas helped to avoid this risk during 24 mon of storage at 12–20°C. The total phenolic content of both cultivars oils decreased during storage because their oxidation protected the oils from autoxidation. The content of total volatile compounds in oils decreased continuously during storage at 12–20°C, whereas it increased over 10 (Coratina cv.) and 15 (Leccino cv.) mon and then diminished when the storage temperature was 40°C. The same behavior, i.e., increase then decrease, was ascertained for trans‐2‐hexenal. The hexanal content of oils increased continuously during storage because this compound is formed by the decomposition of the 13‐hydroperoxide of linoleic acid.
Determination of MG and TG phase composition by time‐domain NMR
Authors: van Duynhoven John , Dubourg Isabelle , Goudappel Gert‐Jan , Roijers Eli 
Published: November 2006

AbstractThe feasibility of time‐domain NMR curve‐fitting methodology for the quantitative determination of TG blend phase compositions was investigated. By studying a range of TG in their different crystal forms, it was shown that the transverse NMR relaxation characteristics of TG differ for the respective crystal polymorphs {α,β,β′}. This enables the TG polymorphism in fat blends to be quantitatively determined by curve fitting. If a liquid phase is present in the blend, curve fitting is able to determine the solid fat content, and the results compare well with those of the accepted NMR methods. The curve‐fit method is less hindered by some of the disadvantages of these accepted methods, such as the use of a calibration factor.