Acids In Vegetable Oils Research Articles

Localisation of C=C Bond and absolute quantification of unsaturated Fatty Acids in Vegetable Oils based on photochemical derivatisation reaction coupled with mass spectrometry

SummaryIn this study, a strategy based on photochemical derivatisation and stable isotope labelling coupled with mass spectrometry (MS) for rapid and accurate identification and quantification of unsaturated fatty acids (UFAs) in vegetable oils was developed. Acetone was employed to label double bond(s) of UFAs via Paternò–Büchi (PB) reaction. The acetone‐labelled UFAs could produce diagnostic ions specific to the locations of carbon–carbon double bond (C=C) in collision‐induced dissociation (CID), which enabled confident assignment of C=C locations in UFAs. Furthermore, absolute quantification was achieved by using d6‐acetone‐labelled UFAs as internal standard to minimise the quantitation deviation due to nonuniformity response and ion suppression effects. By exploiting this method, precise identification and quantification of UFAs in nine kinds of vegetable oils including three kinds of Chinese special vegetable oils were achieved. This method exhibits a powerful potential use for the localisation of C=C bond(s) and quantitative analysis of UFAs, which is valuable for discovery of unusual UFAs in special oils and crops, and quality control of edible oils.

Exposure of Human Gastric Cells to Oxidized Lipids Stimulates Pathways of Amino Acid Biosynthesis on a Genomic and Metabolomic Level.

The Western diet is characterized by a high consumption of heat-treated fats and oils. During deep-frying processes, vegetable oils are subjected to high temperatures which result in the formation of lipid peroxidation products. Dietary intake of oxidized vegetable oils has been associated with various biological effects, whereas knowledge about the effects of structurally-characterized lipid peroxidation products and their possible absorption into the body is scarce. This study investigates the impact of linoleic acid, one of the most abundant polyunsaturated fatty acids in vegetable oils, and its primary and secondary peroxidation products, 13-HpODE and hexanal, on genomic and metabolomic pathways in human gastric cells (HGT-1) in culture. The genomic and metabolomic approach was preceded by an up-to-six-hour exposure study applying 100 µM of each test compound to the apical compartment in order to quantitate the compounds’ recovery at the basolateral side. Exposure of HGT-1 cells to either 100 µM linoleic acid or 100 µM 13-HpODE resulted in the formation of approximately 1 µM of the corresponding hydroxy fatty acid, 13-HODE, in the basolateral compartment, whereas a mean concentration of 0.20 ± 0.13 µM hexanal was quantitated after an equivalent application of 100 µM hexanal. An integrated genomic and metabolomic pathway analysis revealed an impact of the linoleic acid peroxidation products, 13-HpODE and hexanal, primarily on pathways related to amino acid biosynthesis (p < 0.05), indicating that peroxidation of linoleic acid plays an important role in the regulation of intracellular amino acid biosynthesis.

The role of pole and molecular geometry of fatty acids in vegetable oils droplet on ignition and boiling characteristics

Vegetable oils consist of glycerol and three variants of fatty acid. Each fatty acid gives different influence on ignition process which is important to be studied. Generally, fatty acids are categorized into polar and nonpolar fatty acids. Both of them have straight and bent molecule geometry. Their roles on evaporation and ignition are discussed based on their polarity and geometry. The study was done with a single droplet from various vegetable oils. Results show polar fatty acids are more reactive due to electric charge. Long and bent polar fatty acids are more reactive than the short and straight polar one since the former one has stronger polarity and higher electron mobility. The highest electron mobility in long and bent unsaturated fatty acid makes molecules less tight, thus, evaporation rate becomes the fastest. However, reactivity decreases since the polarity is neutralized by electron mobility. The existence of more than one double bonds in carbon chain of polyunsaturated oil partially blocks electron mobility, therefore, the polarity becomes stronger while electron mobility still high so it becomes more reactive with high evaporation rate. Faster evaporation rate makes ignition temperature lower since heat energy is changed into latent heat for phase change during evaporation.

Application of a molecularly imprinted polymer based on the polyimide as a piezosensor selective coating for determining the oleic acid in oils

When creating selective piezoelectric sensors based on the molecularly imprinted polymers (MIPs), the possibility of using quantum-chemical modeling for the selection of their synthesis conditions was considered. The starting polymer for MIPs production was polyamic acid (PAA), which is a copolymer of 1,2,4,5-benzenetetracarboxylic acid and 4,4′-diaminodiphenyl ether. Applying two-step thermal imidization of PAA solution in the presence of a template, the molecularly imprinted polyimide was formed. The oleic acid served as the template. The structures were optimized and the energies were calculated by the Gaussian 09 software using the DFT method at the B3LYP/6-31G(d,p) level with the basis set superposition error (BSSE) correction. It was shown that the structure of the fatty acid radical plays the decisive role in the formation of prints and, accordingly, in the selectivity of the polymer. Based on the quantum-chemical calculations, the optimal ratio of the reagents in pre-polymerization mixture was set to 4:1. The molecularly imprinted polymers for oleic acid have been synthesized on the surface of piezoelectric sensors by the non-covalent imprinting method. The ability of the obtained sensors to recognize this acid in the binary and ternary model mixtures of fatty acids was experimentally evaluated, and it was found that the sensor based on the molecularly imprinted polymer was most sensitive to the oleic acid, which had the detection limit of 0.14 g/dm 3 . Piezoelectric sensors based on MIPs were approved for the determination of the fatty acid in vegetable oils (sunflower, corn, olive, linseed, and rapeseed). The chromatography-mass spectrometry was used as the comparison method, and it was found that the difference in determination results was less than 10%. Keywords : molecularly imprinted polymers, polyamic acid, polyimide, oleic acid, computer modeling, modified piezosensors (Russian) DOI: http://dx.doi.org/10.15826/analitika.2019.23.1.006 Cao Nhat Linh, О.V. Duvanova, A.N. Zyablov Voronezh State University, Universitetskaya square, 1, Voronezh, 394018, Russian Federation

Deep Eutectic Solvent-based Vortex-assisted Dispersive Liquid–liquid Microextraction Combined with High Performance Liquid Chromatography for the Determination of Phenolic Acids in Vegetable Oils

Deep Eutectic Solvent-based Vortex-assisted Dispersive Liquid–liquid Microextraction Combined with High Performance Liquid Chromatography for the Determination of Phenolic Acids in Vegetable Oils

Fatty Acids of Vegetable Oils as Components of Anti-Wear Diesel-Fuel Additives

Comparative study of fatty acids isolated from vegetable (sunflower and cotton-seed) oils and tall oil fatty acids was carried out as regards the possibility of their application as raw material for production of anti-wear additives to low-sulfur diesel fuels. It was shown that the additives are close to each other in the fatty-acid composition and physicochemical and service properties, which makes it possible to extend the raw-material resources for additives of this type and to diminish the import purchases.

Use of Piezoelectric Sensors for the Determination of Oleic and Palmitic Acids in Vegetable Oils

Piezoelectric sensors based on molecularly imprinted polymers (MIPs) for sensing oleic (MIP-Oleic) and palmitic (MIP-Palmitic) acids were tested in the analysis of vegetable oils. When creating the MIP sensors, electrodes were modified with the PM polyimide (dianhydride of 1,2,4,5-benzenetetracarboxylic acid and 4,4′-diaminodiphenyl oxide). Values of the imprinting factor and selectivity coefficients of the molecularly imprinted polymers for sensing fatty acids were compared. Chromatography mass spectrometry was used as a comparison method. The difference between the results of the determination of acids by using a piezoelectric sensor and by chromatography mass spectrometry does not exceed 10%. It is established that sensors modified with molecularly imprinted polymers are selective to the acid that served as a template for the polymer synthesis.

Electrochemical conversion of palmitic acid via Kolbe electrolysis for synthesis of n-triacontane

Fatty acids in vegetable oils and animal fats are a potential feedstock for the production of synthetic waxes, and this kind of waxes can be a substitute for petroleum waxes in the future because the feedstock is renewable. This paper described an optimization study on the production of n-triacontane (NTA) from palmitic acid via Kolbe electrolysis using a biphasic solvent system (H2O/MeOH as aqueous phase, petroleum ether as organic phase). Response surface methodology (RSM) and Taguchi methodology (TM) were employed to research the production of NTA affected by amounts of KOH, reaction temperature, cell voltage and reaction time. On the basis of analysis of variance and range analysis of the two methods above, the maximum NTA yield was achieved at amounts of KOH of 1.3 equiv., reaction temperature of 57 °C, cell voltage of 20.0 V and reaction time of 20 h for RSM; while the amounts of KOH of 1.3 equiv., reaction temperature of 55 °C, cell voltage of 20.0 V and reaction time of 20 h for TM. Under these optimal conditions, the experimental yields of NTA were 69.5% and 64.7% for RSM and TM, respectively. The final product met the relevant standards of the needle penetration, lead, water soluble acids and alkalis, odor and polycyclic aromatic hydrocarbons by referring to Chinese waxes product standards. The results showed strong potential market applications of Kolbe electrolysis waxes.

Determination of phenolic acids in palm oil samples by HPLC-UV-AD using homemade flow cell

The concentration of phenolic acids in vegetable oils is an important criterion for the assessment of the quality of oils with regard to their freshness, the maintenance of their properties, their storage and their influence on human nutrition and health.

Prediction of Edible-oil Iodine Values Based on Raman and near Infrared Spectroscopy

Based on Raman and near infrared spectroscopy (NIR), the modeling of edible-oil iodine value was conducted following chemometrics and support vector machine regression (SVR). The Raman and NIR spectral data of 44 oil samples were collected and preprocessed. The preprocessed spectral data at characteristic wavelengths were extracted with CARS and iPLS methods. Parameter optimization was performed following the grid search algorithm (GS), for the SVR iodine value prediction models. The results show that all the models built could predict the iodine values to some extent. An NIR-MSC-iPLS-SVR model exhibited the greatest stability and its correlation coefficient R of the prediction set reached 97.69%. The results show that NIR has more advantages in the fast prediction of iodine values and can be utilized to manufacture portable spectral instruments for edible-oil iodine-value determination. Vegetable oils can afford human body unsaturated fatty acids, vitamins, and other nutrients [1]. Wherein, the unsaturated fatty acids can ensure the physiological function of cells, reduce cholesterol contents, and perfect blood circulation [2]. The unsaturated fatty acid content can be indicated by unsaturation degree and iodine value (iodine number). The iodine value refers to the grams of iodine consumed in the addition reaction of 100 g of oil. The higher the iodine value is, the greater the unsaturation degree is, and the higher the unsaturated fatty acid content is. The iodine value determination methods include Wijs method (national standard), high-performance liquid chromatography (HPLC) method, and so forth [3-4]. Wherein, the Wijs method is precise and commonly used. Nevertheless, because the sample and titrant solution are immiscible, at the end point of titration, the color change is too slow. And, the method is tedious and requires a large amount of hazardous organic solvents [5-6]. Compared with the Wijs method, the spectral method is fast, efficient, and free of sample pretreatment. Hence, it has been increasingly used in oil and food industries [7]. Yu Yanbo et al. [8] used near infrared spectroscopy (NIR) technology to build a prediction model for the prediction of contents of 4 fatty acids in vegetable oils. María Á. Carmona et al. [9] identified oils and determined iodine values based on Raman spectroscopy.

Regioisomeric distribution of 9- and 13-hydroperoxy linoleic acid in vegetable oils during storage and heating.

BACKGROUNDThe oxidative deterioration of vegetable oils is commonly measured by the peroxide value, thereby not considering the contribution of individual lipid hydroperoxide isomers, which might have different bioactive effects. Thus, the formation of 9‐ and 13‐hydroperoxy octadecadienoic acid (9‐HpODE and 13‐ HpODE), was quantified after short‐term heating and conditions representative of long‐term domestic storage in samples of linoleic acid, canola, sunflower and soybean oil, by means of stable isotope dilution analysis–liquid chromatography‐mass spectroscopy.RESULTSAlthough heating of pure linoleic acid at 180 °C for 30 min led to an almost complete loss of 9‐HpODE and 13‐HpODE, heating of canola, sunflower and soybean oil resulted in the formation of 5.74 ± 3.32, 2.00 ± 1.09, 16.0 ± 2.44 mmol L–1 13‐HpODE and 13.8 ± 8.21, 10.0 ± 6.74 and 45.2 ± 6.23 mmol L–1 9‐HpODE. An almost equimolar distribution of the 9‐ and 13‐HpODE was obtained during household‐representative storage conditions after 56 days, whereas, under heating conditions, an approximately 2.4‐, 2.8‐ and 5.0‐fold (P ≤ 0.001) higher concentration of 9‐HpODE than 13‐HpODE was detected in canola, soybean and sunflower oil, respectively.CONCLUSIONA temperature‐dependent distribution of HpODE regioisomers could be shown in vegetable oils, suggesting their application as markers of lipid oxidation in oils used for short‐term heating. © 2017 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Experimental Modeling and Simulation of Supercritical Fluid Extraction of Moringa oleifera Seed Oil by Carbon Dioxide

Moringa oleifera seed is an important source of high oleic acid in vegetable oil. In the present work, supercritical extraction of Moringa seed oil has been carried out to study the influence of operating temperature, pressure, particle size, carbon dioxide flow rate, and co-solvent addition by performing experiments in the range of 333–373 K, 20–40 MPa, 0.50–1.00 mm, 0.83 × 10−4–2.50 × 10−4 kg/s, and 0–10% ethanol. The extraction data have been successfully modeled by extended Lack’s model and fitting parameters are optimized by the Box global optimization technique. The results showed that pressure has a significant effect followed by temperature, co-solvent, solvent flow rate, and particle size.

Antibacterial Finishing of 100% Cotton Fabric with β-Cyclodextrin-Ozonated Olive Oil Inclusion Complex

Ozone (O3) was reacted with unsaturated fatty acids in vegetable oils to yield products with antibacterial activity. In this paper, olive oil, containing large amounts of unsaturated fatty acids, was ozonated and characterized with gas chromatography (GC), Fourier transform infrared (FTIR), and thermogravimetric (TGA) analyses. The ozonated oils were sequestered in β-cyclodextrin (β-CD) inclusion complexes and applied onto 100% cotton fabric. The inclusion complex was analyzed with scanning electron microscopy (SEM), FTIR, and TGA, and treated fabric with FTIR and SEM. The antibacterial activity of the ozonated oil and treated fabric was assessed using ASTM E2149-01. The results showed that the ozonated oil had high antibacterial activity and the resulting β-CD/ozonated olive oil inclusion complex also had antibacterial activity when applied to cotton fabric.

Investigation and Optimization of Use of Anionic Collectors in Direct Flotation of Bauxite Ores

Bauxite is the main raw material for the alumina industry. Direct flotation is the most widely used method for bauxite beneficiation. In this study, a large number of direct flotation tests were carried out using several anionic reagents. The testing concluded that vegetable oil acid (VOA), naphthenic acid (NA) and lauryl polyoxyethylene phosphate (AEP12) were the three outstanding collectors for bauxite direct flotation. ZMC collector was mixed and prepared using VOA, NA and AEP12, in which the mass ratio of VOA, NA and AEP12 was 1:1:0.5. When processing the bauxite ores of the mass ratio of Al2O3 to SiO2 (A/S) = 4.99, the A/S of the final concentrate was 7.08 and the recovery of Al2O3 was 90.22%. When processing ores of A/S = 4.5, the A/S of the final concentrate was 7.04 and the recovery of Al2O3 was 92.16%. Thus, it can be seen that properties and behaviors of the ZMC reagent were remarkable and met the demands of the Lime-Bayer Process.

Fatty acid digestibility in gilthead sea bream fed diets containing native, re-esterified or acid vegetable oils

Re-esterified vegetable oils are obtained from a chemical esterification reaction between vegetable acid oils and glycerol. Due to their properties, it is expected that they have a higher nutritive value than their corresponding acid oils and a better digestibility than their native counterparts. The aim of this study was to determine the effect of re-esterified oils with a different monoacylglycerol (MAG) and diacylglycerol (DAG) content, produced from palm or rapeseed, on fatty acid digestibility in gilthead sea bream (Sparus aurata). Triplicate groups of fish were fed nine experimental diets containing different oils during 28 days. For each source, four different types of oil were used: native, re-esterified low or high in MAG and DAG and acid. A commercial fish oil was used for the control diet. Diets containing re-esterified oils had better apparent digestibility coefficients (ADC) of total fatty acids than acid oil diets. Re-esterified oils do not negatively affect apparent digestibility coefficients of fatty acids when compared to their corresponding native oils and could be incorporated as a source of energy in diets for gilthead sea bream. An improvement in digestibility compared to the native oil diet was only obtained in palm re-esterified oil high in MAG and DAG.

The research and analysis of the chocolate nut butter with polyfunctional properties

The usefulness of the protein and fat composition consisting of whey and blended mixture of vegetable oils in the production technology of chocolate nut butter with a sweet extract from stevia leaves is theoretically proved and verified under production conditions. The composition of the fatty base of the product comprising a mixture of refined sunflower oil and palm oil is developed. The paper examines the polyfunctionality of the chocolate nut butter on the human body, which is due to a high content of whey protein, polyunsaturated fatty acids of vegetable oils and complete replacement of sugar with the sweet extract from stevia leaves. The study of organoleptic characteristics and the chromatographic quantitative assessment of fatty acid and amino acid composition of the final product revealed that the resulting composition has a high nutritional and biological value. Adding the blended fat composition favorably affects the structure and fatty acid composition of the butter, allowing to obtain a product of a given structure and properties.

Rapid Determination of Unsaturated Fatty Acids in Vegetable Oil by Raman Spectroscopy and Chemometrics

ABSTRACTThe accuracy for the determination of total monounsaturated and polyunsaturated fatty acids in vegetable oil by Raman spectroscopy was enhanced by spectral wavelength selection with competitive adaptive reweighted sampling to obtain partial least squares models based on a small subset of wavelengths. Wavelengths of 26 and 31 were selected from the 842 original points for the total monounsaturated and polyunsaturated fatty acids, respectively. Compared to full spectral models and four frequently-used variable selection methods, the competitive adaptive reweighted sampling achieved better results. The external correlation coefficients for total monounsaturated fatty acids and polyunsaturated fatty acids were increased to 0.9555 and 0.9963, and root mean square errors of prediction were reduced to 0.0207 and 0.0054. The results indicate that a portable Raman spectrometer using competitive adaptive reweighted sampling with partial least squares may be a promising approach for the determination of unsaturated fatty acids in vegetable oil.

Long-term feeding a plant-based diet devoid of marine ingredients strongly affects certain key metabolic enzymes in the rainbow trout liver.

Incorporation of a plant blend in the diet can affect growth parameters and metabolism in carnivorous fish. We studied for the first time the long-term (1 year) metabolic response of rainbow trout fed from first feeding with a plant-based diet totally devoid of marine ingredients. Hepatic enzymes were analyzed at enzymatic and molecular levels, at 3, 8 and 24 h after the last meal to study both the short-term effects of the last meal and long-term effects of the diet. The results were compared with those of fish fed a control diet of fish meal and fish oil. Growth, feed intake, feed efficiency and protein retention were lower in the group fed the plant-based diet. Glucokinase and pyruvate kinase activity were lower in the livers of trout fed the plant-based diet which the proportion of starch was lower than in the control diet. Glutamate dehydrogenase was induced by the plant-based diet, suggesting an imbalance of amino acids and a possible link with the lower protein retention observed. Gene expression of delta 6 desaturase was higher in fish fed the plant-based diet, probably linked to a high dietary level of linolenic acid and the absence of long-chain polyunsaturated fatty acids in vegetable oils. Hydroxymethylglutaryl-CoA synthase expression was also induced by plant-based diet because of the low rate of cholesterol in the diet. Changes in regulation mechanisms already identified through short-term nutritional experiments (<12 weeks) suggest that metabolic responses are implemented at short term and remain in the long term.

Flavonoids are preserving phenolic acids in vegetable oils under microwave heating

Flavonoids are preserving phenolic acids in vegetable oils under microwave heating

Lifelong diet including common unsaturated fatty acids extends the lifespan and affects oxidation in Caenorhabditis elegans consistently with hormesis model

Diets abundant in unsaturated fatty acids (UFAs) help to support a longer and healthier life. We evaluated effects of dietary oleic acid (OA), linoleic acid (LnA), and linolenic acid (ALA) on lifespan and physical activities of Caenorhabditis elegans (C. elegans). Supplementation at doses per plate of 0.5 mg OA, 0.1 mg LnA, or 0.5 mg ALA extended the lifespan of C. elegans by 10.49, 14.17, or 8.47%, respectively (p &lt; 0.05). At these doses, LnA and ALA significantly inhibited growth, pharyngeal pumping, reproduction, and respiration (p &lt; 0.05), while OA did not influence these physiological activities (p &gt; 0.05). Furthermore, OA significantly increased superoxide dismutase, catalase, and glutathione peroxidase activities. Based on results obtained with wild‐type N2, eat‐2, and sod‐2‐mutated C. elegans, OA extended C. elegans lifespan through a hormesis mechanism by activating antioxidant enzymes. In contrast, LnA and ALA acted via a caloric restriction mechanism. Consistent with calorie restriction being a type of stress, however, lifespan was shortened as LnA and ALA doses were further increased. Therefore, the effects of all three fatty acids might be regarded as being consistent with a classic hormesis effect.Practical applications: Oleic acid, linoleic acid, and linolenic acid are the three most common unsaturated fatty acids in vegetable oils. The beneficial effects of oleic acid, linoleic acid, and linolenic acid supplementation on lifespan, normal physiological activities, and oxidation in our study support consumers choosing vegetable oils in their diets.Supplementation with 0.5 mg OA, 0.1 mg LnA or 0.5 mg ALA extended the lifespan of C. elegans by 10.49%, 14.17% or 8.47%, respectively (p &lt; 0.05). At these doses, LnA and ALA significantly inhibited growth, pharyngeal pumping, reproduction and respiration, while OA did not influence these physiological activities and significantly increased superoxide dismutase, catalase and glutathione peroxidase activities. Using the eat‐2, and sod‐2 mutated strains, the anti‐aging mechanism of OA was hormesis, while LnA and ALA acted via caloric restriction.