Acid Composition Of Vegetable Oils Research Articles

Tribological studies of potential vegetable oil-based lubricants containing environmentally friendly viscosity modifiers

The amphiphilic properties that result from the fatty acid composition of vegetable oils contribute to a better lubricity and effectiveness as anti-wear compounds than mineral or synthetic lubricant oils. Despite these advantages, vegetable oils show only a limited range of viscosities and this constrains their use as suitable biolubricants in many industrial applications. For the reason, ethylene–vinyl acetate copolymer (EVA) and ethyl cellulose (EC) have been added to the vegetable oil-based lubricants studied. To address this issue, the frictional and lubricant film-forming properties of improved vegetable oil-based lubricants (high oleic sunflower (HOSO), soybean (SYO) and castor (CO) oils), blended with 4% (w/w) of EVA and 1% (w/w) of EC, have been studied. It has been found that castor oil shows the best lubricant properties, when compared to high oleic sunflower and soybean oil, with very good film-forming properties and excellent friction and wear behaviour. This can be attributed to its hydroxyl functional group that increases both the viscosity and polarity of this vegetable oil. Regarding the effect of the viscosity modifiers studied, ethylene–vinyl acetate copolymer exerts a slight effect on lubricant film-forming properties and, thus, helps to reduce friction and wear mainly in the mixed lubrication region. Ethyl cellulose, on the other hand, was much more effective, mainly with castor oil, in improving both mixed and boundary lubrication.

Prediction of fatty acid composition of vegetable oils based on rheological measurements using nonlinear models

AbstractThe aim of this study was to model the fatty acid composition of vegetable oils by using the adaptive neuro fuzzy inference system (ANFIS) and artificial neural network (ANN) based on rheological measurements. For this aim, seven different refined vegetable oils (hazelnut, soybean, sunflower, olive, canola, corn, and cotton seed) were used. Olive oil had the highest viscosity value of 0.067 Pa s. Principal component analysis (PCA) was performed to determine the correlations among the fatty acids of the oils to reduce parameters which were modeled. PC1 composed of C18:0, C18:1, C18:2, and C20:0 as PC2 composed of C16:0, C18:3, and C22:0. After determination of the fatty acid composition and the rheological properties of the oils, ANN and ANFIS models were established. The inputs were selected as oil type, shear rate and shear stress and the outputs were C16:0 and C18:2. The root mean square error (RMSE), mean absolute error (MAE), and determination coefficient (R2) were used for testing the accuracy of the models. This comparison showed that ANFIS and ANN achieved a satisfactory prediction for fatty acid composition of the vegetable oils studied and ANFIS is better than ANN.Practical applications: Determination of the fatty acid composition of vegetable oils is important for the assessment of the purity of the oils as well as the nutritional quality. The fatty acid composition of the oils affects their rheological characteristics. Rheological measurements are easier than chromatographic analysis. Therefore, we aimed to establish a model for prediction of the fatty acid composition of the oils based on their rheological behaviors.

Prediction of Biodiesel Properties from Fatty Acid Composition using Linear Regression and ANN Techniques

Biodiesel is currently the most widely accepted alternative fuel for diesel engines due to its various advantages. The fatty acid composition of vegetable oils affects the fuel properties of biodiesel, such as viscosity, flash point, fire point, cloud point, pour point, iodine value and saponification value. In the present work, biodiesel was prepared from different vegetable oils and its physical properties measured. Artificial neural networks (ANNs) with 6-4-1 and 6-5-1 architecture were used to determine the relative importance of the fatty acid (palmitic acid, stearic acid, oleic acid, linoleic acid, linolenic acid and erucic acid) composition of vegetable oils affecting biodiesel properties. The results show that the ANNs precisely predict the properties of biodiesel derived from certain vegetable oils better than a linear regression model. The relative importance of the input variables shows quantitatively the effect on biodiesel properties.

Influence of Vegetable Oils on Micellization of Lutein in a Simulated Digestion Model

AbstractLutein and zeaxanthin are selectively accumulated in the macula of the retina, yet their bioavailability is influenced by various dietary factors. Insights regarding the effects of dietary lipids on lutein micellization that is available for absorption are limited. This study investigated the influence of vegetable oils on the relative efficiency of lutein micellization using in vitro digestion procedure. Lutein dispersed in either olive oil (OO), corn oil (CO), soybean oil (SBO), sunflower oil (SFO), groundnut oil (GNO), rice bran oil (RBO) or palm oil (PO) was subjected to simulated gastric and small intestinal digestion. Results showed that the efficiency of micellization of lutein dispersed in olive oil exceeds the other vegetable oils. The percent lutein micellization was in the order of OO > GNO > RBO > SFO > CO > SBO > PO. In comparison, the values for OO were higher than GNO (11%), RBO (18.3%), SFO (19%), CO (21.7%), SBO (30.5%) and PO (35.2%), respectively. These results suggest that OO rich in oleic acid may favor the incorporation of lutein into micelles at the intestinal level. To conclude, the type of vegetable oil in which carotenoids are dispersed is important to achieve an enhanced bioavailable lutein. The correlation between the micellizable lutein and fatty acid composition of vegetable oils are discussed.

Correlation of fatty acid composition of vegetable oils with rheological behaviour and oil uptake

Abstract The fatty acid compositions of seven edible vegetable oils were investigated and correlated with their rheological behaviours and the amount of absorbed oils to fried products. All oil samples showed constant viscosity as a function of shear rate, exhibiting Newtonian behaviours. The highest viscosity was observed in hazelnut oil, followed by olive, canola, corn, soybean, sunflower, and grapeseed oils. In addition, a high correlation ( R 2 = 0.94) demonstrated that the flow behaviours of vegetable oils were positively governed by their major components (18:1 and 18:2 fatty acids). It was also shown that a more rapid change in viscosity with temperature was observed in the oils containing more double bonds ( R 2 = 0.71). Furthermore, even though the overall tendency was that the potato strips fried in the oils with high viscosity appeared to cause more oil uptake, a significant effect of oil types on oil uptake was not observed.

Increasing gamma‐ and delta‐tocopherols in oils improves oxidative stability

AbstractOver the past two decades, plant geneticists have revolutionized how fatty acid compositions of vegetable oils are optimized to improve oxidative stability and functionality. Now, the expertise of plant geneticists is reaching beyond altering fatty acids to changing other oil components such as tocopherols. Basic lipid research on optimizing tocopherol profiles and ratios in vegetable oils is providing information for geneticists to breed the next generation of oxidatively stable vegetable oils. This review will discuss three studies; first, a basic study to determine the oxidative stability provided by the addition of pure gamma and delta tocopherols to oils treated to remove natural tocopherols; second, a practical study to evaluate the oxidative stability of mid‐oleic sunflower oil from seeds modified by plant breeding to contain high amounts of γ‐ and δ‐tocopherols; and third, a frying test to determine the effects of gamma tocopherol addition.

Analysis of drying oils used as binding media for objects of art by capillary electrophoresis with indirect UV and conductivity detection.

Capillary electrophoresis (CE) was applied to analyse the long-chain fatty acid composition of vegetable oils, and their degradation products formed upon ageing when drying oils are used as binding media. The analytes were detected with contactless conductivity detection (CCD) and indirect UV absorption, both detectors positioned on-line at the separation capillary. The long-chain fatty acids were resolved in a background electrolyte (BGE) consisting of phosphate buffer (pH = 6.86, 15 mM) containing 4 mM sodium dodecylbenzensulfonate, 10 mM Brij 35, 2% (v/v) 1-octanol and 45% (v/v) acetonitrile. As in this system dicarboxylic analytes, the products of oxidative degradation of unsaturated fatty acids, cannot be determined, a suitable background electrolyte was developed by the aid of computer simulation program PeakMaster. It makes use of a 10 mM salicylic acid, 20 mM histidine buffer, pH 5.85, which combines buffering ability with the optical properties obligatory for indirect UV detection. This buffer avoids system eigenpeaks, which are often impairing the separation efficiency of the system. Separation of the dicarboxylic analytes was further improved by a counter-directed electroosmotic flow (EOF), obtained by dynamically coating the capillary wall with 0.2 mM cetyltrimethylammonium bromide. Long-chain fatty acids and their decomposition products could be determined in recent and aged samples of drying oils, respectively, and in samples taken from two paintings of the 19th century.

Changes in the fatty acid composition of vegetable oils in model doughs submitted to conventional or microwave heating

SummaryAn experimental investigation ascertained the variation of the contents of saturated, unsaturated and polyenoic fatty acids, as well as of the trans‐isomers of unsaturated fatty acids, in different vegetable oils (virgin olive oil, refined sunflower, refined peanut) submitted to either conventional or microwave heating. The results obtained showed that heat treatment causes a worsening of the nutritional quality of the fatty fraction. As a consequence, the contents of unsaturated and polyenoic fatty acids decreased, with greater variations in the oils heated by microwave than by a conventional oven, while the saturated fatty acid contents did not change substantially. The heat treatments also caused an increase in the trans‐isomers of unsaturated fatty acids and this was more evident after microwave treatment.

Determination of the fatty acid composition of saponified vegetable oils using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry

A method using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS) for the determination of the fatty acid composition of vegetable oils is described and illustrated with the analysis of palm kernel oil, palm oil, olive oil, canola oil, soybean oil, vernonia oil, and castor oil. Solutions of the saponified oils, mixed with the matrix, meso-tetrakis(pentafluorophenyl)porphyrin, provided reproducible MALDI-TOF spectra in which the ions were dominated by sodiated sodium carboxylates [RCOONa + Na]+. Thus, palm kernel oil was found to contain capric acid, lauric acid, myristic acid, palmitic acid, oleic acid, and stearic acid. Palm oil had a fatty acid profile including palmitic, linoleic, oleic, and stearic. The relative percentages of the fatty acids in olive oil were palmitoleic (1.2 +/- 0.5), palmitic (10.9 +/- 0.8), linoleic (0.6 +/- 0.1), linoleic (16.5 +/- 0.8), and oleic (70.5 +/- 1.2). For soybean oil, the relative percentages were: palmitoleic (0.4 +/- 0.4), palmitic (6.0 +/- 1.3), linolenic (14.5 +/- 1.8), linoleic (50.1 +/- 4.0), oleic (26.1 +/- 1.2), and stearic (2.2 +/- 0.7). This method was also applied to the analysis of two commercial soap formulations. The first soap gave a fatty acid profile that included: lauric (19.4% +/- 0.8), myristic (9.6% +/- 0.5), palmitoleic (1.9% +/- 0.3), palmitic (16.3% +/- 0.9), linoleic (5.6% +/- 0.4), oleic (37.1% +/- 0.8), and stearic (10.1% +/- 0.7) and that of the second soap was: lauric (9.3% +/- 0.3), myristic (3.8% +/- 0.5), palmitoleic (3.1% +/- 0.8), palmitic (19.4% +/- 0.8), linoleic (4.9% +/- 0.7), oleic (49.5% +/- 1.1), and stearic (10.0% +/- 0.9). The MALDI-TOFMS method described in this communication is simpler and less time-consuming than the established transesterification method that is coupled with analysis by gas chromatography/mass spectrometry (GC/MS). The new method could be used routinely to determine the qualitative fatty acid composition of vegetable oils, and, when fully validated by comparison with standard analytical methodologies, should provide a relatively fast quantitative measurement of fatty acid mixtures and/or soap formulations that contain saturated and unsaturated hydrocarbon moieties.

Determination of the fatty acid composition of saponified vegetable oils using matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry

A method using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS) for the determination of the fatty acid composition of vegetable oils is described and illustrated with the analysis of palm kernel oil, palm oil, olive oil, canola oil, soybean oil, vernonia oil, and castor oil. Solutions of the saponified oils, mixed with the matrix, meso-tetrakis(pentafluorophenyl)porphyrin, provided reproducible MALDI-TOF spectra in which the ions were dominated by sodiated sodium carboxylates [RCOONa + Na]+. Thus, palm kernel oil was found to contain capric acid, lauric acid, myristic acid, palmitic acid, oleic acid, and stearic acid. Palm oil had a fatty acid profile including palmitic, linoleic, oleic, and stearic. The relative percentages of the fatty acids in olive oil were palmitoleic (1.2 ± 0.5), palmitic (10.9 ± 0.8), linoleic (0.6 ± 0.1), linoleic (16.5 ± 0.8), and oleic (70.5 ± 1.2). For soybean oil, the relative percentages were: palmitoleic (0.4 ± 0.4), palmitic (6.0 ± 1.3), linolenic (14.5 ± 1.8), linoleic (50.1 ± 4.0), oleic (26.1 ± 1.2), and stearic (2.2 ± 0.7). This method was also applied to the analysis of two commercial soap formulations. The first soap gave a fatty acid profile that included: lauric (19.4% ± 0.8), myristic (9.6% ± 0.5), palmitoleic (1.9% ± 0.3), palmitic (16.3% ± 0.9), linoleic (5.6% ± 0.4), oleic (37.1% ± 0.8), and stearic (10.1% ± 0.7) and that of the second soap was: lauric (9.3% ± 0.3), myristic (3.8% ± 0.5), palmitoleic (3.1% ± 0.8), palmitic (19.4% ± 0.8), linoleic (4.9% ± 0.7), oleic (49.5% ± 1.1), and stearic (10.0% ± 0.9). The MALDI-TOFMS method described in this communication is simpler and less time-consuming than the established transesterification method that is coupled with analysis by gas chromatography/mass spectrometry (GC/MS). The new method could be used routinely to determine the qualitative fatty acid composition of vegetable oils, and, when fully validated by comparison with standard analytical methodologies, should provide a relatively fast quantitative measurement of fatty acid mixtures and/or soap formulations that contain saturated and unsaturated hydrocarbon moieties. Copyright © 2000 John Wiley & Sons, Ltd.

Brief communication. Genetic relationships between loci for palmitate contents in soybean mutants

Elevated palmitate content in soybean [Glycine max (L.)] oil may be important for the production of some food and industrial products. The palmitate content of commercial cultivars is approximately 11.0%. Soybean mutants with elevated and reduced palmitate have been developed. Elevated palmitate in J10 (o15.6%) and C1727 (o17.3%), and reduced palmitate in C1726 (o8.6%) were controlled by sop2, fap2, and fap1, respectively. The genetic system for elevated palmitate in KK7 (o13.5%) was unknown. Reciprocal crosses were made as Bay 3 J10, Bay 3 C1727, Bay 3 KK7, C1727 3 J10, C1726 3 J10, J10 3 KK7, C1727 3 KK7, and C1726 3 KK7 to determine if the sop2 allele in J10 was different from fap2 and fap1, and if the allele in KK7 was different from those of sop2, fap2, and fap1. No maternal effect was observed in any of the crosses. The phenotypic segregation ratio and the genotypic evaluation of F2 plants from C1726 3 J10, J10 3 KK7, C1727 3 KK7, and C1726 3 KK7 indicated that the sop2 allele in J10 was at a different locus from fap1, and that the allele in KK7 was at a different locus from sop2, fap2, and fap1. The lack of transgressive segregation in F2 seeds and their F2 plants with putative lower and higher palmitate content of C1727 3 J10 indicated that the sop2 allele was at the same locus as fap2. The sop2 allele in J10 was given the permanent designation of fap2 (J10) and the allele in KK7 was temporarily designated fapx. Lines with the fap2fap2fapxfapx genotype may provide important sources of elevated palmitate in soybean seed oil. The fatty acid composition of vegetable oils influences their use in industrial food applications. Commercial oil seed crops cannot satisfy all the demands of the food industry. The food industry may benefit from vegetable oils with unique fatty acid profiles (Rattray 1991). Alteration of the fatty acid composition of seed oil can be done in different ways (Robbelen et al. 1989). Although natural variability for these traits has been observed in most of the oilseed crops (Knowles 1989; Stefansson et al. 1961), natural genetic variability for palmitate content in commercial soybean (Glycine max L.) is limited (Rattary 1991). Therefore additional variability for this trait must be developed by mutagenesis, the recombination of different mutant genes, or genetic engineering (Ohlrogge et al. 1991). Palmitate is one of the two major saturated fatty acids of soybean oil that is important for the production of plastic fat products, such as shortening and margarine (Vles and Gottenbos 1989). The palmitate content of commercial cultivars is approximately 11.0%. Lines with elevated or reduced palmitate have been developed by different breeding techniques (Bubeck et al. 1989; Erickson et al. 1988; Fehr et al. 1991a,b; Wilcox et al. 1994). Erickson et al. (1988) found that the elevated palmitate content (o17.3%) of C1727 was controlled by fap2, while the reduced content (o8.6%) of C1726 was controlled by fap1. Fehr et al. (1991a) determined that the A21 line, with approximately 20.0% palmitate, had an allele (fap2-b) at the same locus as the fap2 or a tightly linked locus. Schnebly et al. (1994) crossed A24 with approximately 17.7% palmitate to the reduced palmitate lines C1726 (fap1; Erickson et al. 1988) and A22 (fap3; Fehr et al. 1991b), and found that A24 had an allele for elevated palmitate content at a locus independent of fap1 and fap3. The allele was given the permanent designation fap4. The mutant line J10, with approximately 15.6% palmitate, was developed at Saga University by X-ray irradiation of the seeds of Bay (Takagi et al. 1995). Rahman et al. (1996) temporarily designated the allele for palmitate in J10 as sop2 because it’s relationship to other alleles was unknown. Another mutant line, KK7, with approximately 13.5% palmitate was developed from a different M4 population of Bay. The genetic system of elevated palmitate in KK7 has not been determined. The objective of this study was to determine if the sop2 allele in J10 was different from fap2 and fap1, and if the allele in KK7 was different from those of sop2, fap2, and fap1.

Microwave induced rapid transmethylation of fatty acids for analysis of food oil

Microwave irradiation enhances the rate of transmethylation of fatty acids in rice bran oil catalyzed by sodium methoxide (1 or 0.3%). The reaction is completed in 40 s in methanol–toluene (1:10, v/v) and in 15 s in methanol–toluene (1:3, v/v). A high concentration of methanol in the mixture raises the temperature rapidly and results in a fast transmethylation. This method gives a yield of fatty acid methyl esters comparable to, or higher than, the traditional preparation and the conditions are mild enough for analysis of oils rich in polyunsaturated fatty acids. The method can rapidly process multiple samples and can be easily applied to the determination of the fatty acid compositions of vegetable oils. The advantages of this new method are its speed, and the accurate results which are comparable to the conventional technique.

Applications of reversed-phase chromatography and nephelometric detection to analysis of non-polar mixture at microgram level

Non-aqueous reversed-phase chromatography with light-scattering detection is suitable for analysis of various non-polar mixtures. Microprecipitations are conveniently used in solute recovery for further investigations by auxillary chromatographic or spectral techniques. Described applications include determination of the triglyceride and fatty acid composition of vegetable oils, hydrocarbons in petroleum wax, and terpenoids in natural mixtures.

Fatty acid methodology for heated oils

AbstractCriticisms have been voiced concerning the methods employed for determining the fatty acid composition of vegetable oils used in processing of fried foods. In the present study seveveral different vegetable oils were heated under standardized conditions, at frying temperatures and under air, for various periods of time, and then subjected to analyses for fatty acid composition. The methods employed were: UV spectrophotometry; gas‐liquid chromatography (GLC) employing either normalization of the peak areas, direct standards or internal standards; and the enzymic, lipoxidase procedure. The present findings confirm that the drop in iodine value is a good approximation of the reduction of polyunsaturated fatty acids in heated oils. In evaluating liquid nonhydrogenated vegetable oils that had been subjected to heat abuse under standard conditions, all of the analytical methods for the estimation of fatty acid composition, with the exception of normalization of GLC peak areas, give substantially the same results. With hydrogenated vegetable oils, the analytical methods provide values which differ significantly among themselves. Evidence was also presented to show that the quantity of material retained on the gas chromatographic column is directly related to the loss of polyunsaturates for oils heated under controlled conditions. For evaluation of oils from frying operations, the preferred method is the GLC method utilizing internal standards if the purpose is the determination of total polyunsaturated fatty acids. However, if the study being made involves a question of nutritional value, then the measurement of the essential fatty acids by the lipoxidase enzymic procedure is the more valid method for evaluation, of heated oils.