Isomerization Of Oleic Acid Research Articles

Cis-Trans Isomerization of Unsaturated Fatty Acid Methyl Ester by Natural Sulfur Compounds in Model Systems.

Growing evidence indicates that the intake of trans fatty acids (TFAs) increases the risk of numerous diseases, such as cardiovascular diseases. Recently, our group found that certain natural sulfur compounds (allyl isothiocyanate [AITC] and diallyl disulfide [DADS]) promote cis to trans isomerization of fatty acid esters during heat treatment. However, little information is available on the fatty acid isomerization with them. In this study, we investigated the effects of oxygen and α-tocopherol (antioxidant) on isomerization of oleic acid (18:1) methyl ester (OA-ME) in the presence of AITC and DADS. Furthermore, the effect of the simultaneous use of AITC and DADS was evaluated. Our results indicate that oxygen enhances the AITC-induced trans isomerization, and DADS was found to promote trans isomerization but inhibit AITC-induced trans isomerization during heating. Both AITC- and DADS-induced trans isomerization were inhibited by α-tocopherol. These results indicate that the trans isomerization of fatty acids induced by sulfur compounds can be controlled by devising a cooking process and the food ingredients used together.

Determination of 39 fatty acids in liver of rats by gas chromatography-mass spectrometry

Fatty acids not only form phospholipids that contribute to the formation of cell membranes but also participate in many metabolic activities, such as energy storage and cell signal transduction. The liver plays a key role in the synthesis and metabolism of fatty acids. The composition and contents of fatty acids in the liver are closely related to body health. Most fatty acid-detection methods require a large sample size and can detect only a small number of fatty acids. Therefore, a sensitive and efficient method to determine fatty acids in the liver is urgently required. Herein, a method based on gas chromatography-mass spectrometry (GC-MS) was established for the simultaneous determination of 39 fatty acids in 1.1 mg of liver tissue. Different extraction methods and derivatization conditions were compared to develop an optimal sample-treatment method. The performance of two different columns in separating the target fatty acids were also compared. A total of 10 mg of liver was added to 450 μL of normal saline and ground at -35 ℃ to obtain a homogenate. Next, 50 μL of the homogenate (equivalent to 1.1 mg of liver) was added with 750 μL of chloroform-methanol (1∶2, v/v) to extract total fatty acids. The fatty acid extracts were dried under nitrogen, and then derivatized at 100 ℃ for 90 min after being added with methanol containing 5% sulfuric acid. The fatty acid methyl esters were extracted with hexane and then separated on an SP-2560 capillary column (100 m×0.25 mm×0.2 μm; Supelco, USA) via GC-MS. The results revealed that all 39 fatty acid methyl esters detected had good linearities in the certain mass concentration ranges with correlation coefficients (R2) greater than 0.9940. The limits of detection (LOD) and quantification (LOQ) of these methyl esters in the liver were 2-272 ng/mg and 7-906 ng/mg, respectively. The accuracy and precision of the method were evaluated by spiking the liver homogenate with tridecylic acid and eicosanoic acid at low (0.09 μg/mg), moderate (0.90 μg/mg), and high (5.40 μg/mg) concentration levels. The recoveries ranged from 82.4% to 101.0% with an intraday relative standard deviations (RSDs) (n=5) of 3.2%-12.0% and interday RSDs (n=3) of 5.4%-13.4%. The method was successfully applied to detect fatty acids in the livers of four healthy male Sprague-Dawley (SD) rats and four male SD rats with abnormal liver function induced by perfluorooctane sulfonate (PFOS). PFOS is a persistent organic pollutant. Twenty-six fatty acids were detected in the livers of both groups. Among the fatty acids investigated, pentadecanoic acid (C15∶0), γ-linolenic acid (C18∶3n6), and elaidic acid (C18∶1n9t) cannot be detected by the methods reported in the literature. By contrast, the method developed in this study could separate the isomers of oleic acid (elaidic acid, C18∶1n9t; oleic acid, C18∶1n9c) and linolenic acid (linolelaidic acid, C18∶2n6t; linoleic acid, C18∶2n6c). In conclusion, the developed method is simple and can detect a large number of fatty acids using small sample amounts and few reagents. More importantly, it could successfully separate fatty acid isomers. These findings indicate that the developed method is suitable for the detection of fatty acid composition and contents in the liver in clinical and experimental research.

Chemical Characterization and Nutritional Markers of South African Moringa oleifera Seed Oils.

Moringa oleifera Lam (syn. M. ptreygosperma Gaertn.) leaves are globally acclaimed for their nutritional content and mitigation of malnutrition. In most impoverished rural communities including Limpopo, Mpumalanga and KwaZulu Natal of South Africa, powdered leaves of Moringa oleifera are applied as a nutritional supplement for readily available food such as porridge for malnourished children and even breast-feeding mothers. Widely practiced and admired is also the use of the plant seed in the do-it-yourself purification of water by rural South Africans. This study aimed at identifying the chemical and nutritional marker compounds present in South African Moringa oleifera seed oils using high resolution 1-2-dimension gas chromatography in order to give scientific validation to its uses in cosmetics and particularly in culinary practices. Results obtained from two-dimension tandem mass spectrometry chemical signature revealed over 250 compounds, five times more than those reported from one-dimension gas chromatography. Whereas previous reports from gas chromatography-mass spectrometry analysis reported oleic acid (70–78%) as the major compound from oil samples from other countries, M. oleifera seed oil from South Africa is marked by cis-13-octadeaconic acid with 78.62% and 41.9% as the predominant monounsaturated fatty acid in the hexane and dichloromethane extracts respectively. This was followed by cis-vaccenic acid, an isomer of oleic acid at 51% in the acetone extract, 9-octadecanoic acid-(z)-methyl ester at 39.18%, 21.34% and 10.06% in dichloromethane, hexane and acetone extracts respectively. However, a principal component analysis with R2 = 0.98 of the two-dimension tandem mass spectrometry cum chemometric analysis indicated n-hexadecanoic acid, oleic acid, 9-octadecanoic acid-(z)-methyl ester and cis-vaccenic acid with a probability of 0.96, 0.88, 0.80 and 0.79 respectively as the marker compounds that should be used for the quality control of moringa seed oils from South Africa. This study demonstrates that South African Moringa oleifera oils contain C-18 monounsaturated fatty acids similar to oils from Egypt (76.2%), Thailand (71.6%) and Pakistan (78.5%) just to mention but a few. These fatty acids are sunflower and olive oil type-compounds and therefore place moringa seed oil for consideration as a cooking oil amongst its other uses.

Contribution to the chemodiversity of ex Cystoseira sp. - Gongolaria barbata and Ericaria crinita from the Adriatic Sea: Volatiles, fatty acids and major pigments

The aim of present research was to contribute to G. barbata and E. crinita chemodiversity and to the knowledge of specially protected Cystoseira areas. Headspace solid-phase microextraction (HS-SPME) and hydrodistillation (HD) were applied to the fresh (FrGb) and air-dried G. barbata (DrGb) and to the fresh (FrEc) and air-dried E. crinita (DrEc). Sesquiterpenes dominated in the headspace (HS) of FrGb, particularly τ-cadinol and δ-cadinene. Drying of G. barbata caused major change in the HS profile (reduction of the major compounds and increase of alkanes and benzyl alcohol). Cadinane-type sesquiterpenes were the major constituents in HD of FrGb and predominant was τ-cadinol and dolabella-4(16),7-diene-3,18-diol similar as in DrGb HD. The major saturated fatty acid (SFA) in G. barbata was palmitic acid followed by stearic and myristic acids. Besides oleic acid isomers, a significant amounts of arachidonic acid (ARA) were found among polyunsaturated FAs. The major G. barbata pigment was fucoxanthin in F3 fraction and β-carotene in F4 fraction. HS-FrEc main compound was dictyopterene D followed by dictyopterene C. HS-DrEc chemical profile was notable different from HS-FrEc (dictyopterene D was significantly reduced while benzyl alcohol and benzaldehyde increased). The most prominent compound in HD-FrEc was (E)-phytol followed by isopachydictyol A along with different FA esters and hexadecanoic acid. Drying of E. crinita caused notable changes in HD profile (the percentage of phytol decreased followed by the increased of phytone and phyatne and different carbonyl compounds). Like in G. barbata, palmitic, stearic and myristic acids were major SFAs, while higher levels of oleic acid isomers and ARA were determined in E. crinita in comparison to G. barbata. In E. crinita, fucoxanthin was dominant in F3, while in F4 chlorophyll a was detected. Performed research indicates great variability, particularly among the volatile organic compounds of both algae suggesting their chemotaxonomic differences.

Isomerization of Oleic Acid over Acid Zeolites: Design of Experiments and Proposal of a Novel Kinetic Mechanism

Isomerization of Oleic Acid over Acid Zeolites: Design of Experiments and Proposal of a Novel Kinetic Mechanism

Use of Metal-Containing Carbon Nanotubes in Isomerization of Oleic Acid

Use of Metal-Containing Carbon Nanotubes in Isomerization of Oleic Acid

Biochemical Composition of Cumin Seeds, and Biorefining Study.

A new biorefinery approach has been developed in the present study, and applied on cumin (Cuminum cyminum) seeds as a potential source of phytochemicals of interest. Cumin is a popular spice used widely for its distinctive aroma. It is a rich reserve of both vegetable and essential oils. The biorefinery approach here focused on the evaluation of the influence of four different geographical origins (i.e., Lebanon, France, Algeria and Syria) on oil yield and quality in cumin seed, and on the valorization of remaining by-products by investigating their nutritional content and biological activity for the first time. Vegetable and essential oils were extracted, and their compositions were determined. Nutritional traits were also assessed. The delipidated and hydrodistillated cakes just as aromatic water were characterized for their fiber, sugar, protein, phenol and flavonoid contents. Antibacterial and antioxidant activities were also determined. Cumin seeds showed high contents in both vegetable and essential oils, proteins and sugars regardless their origin. Moreover, this Apiaceae species exhibited high levels of petroselinic fatty acid (an isomer of oleic acid) and sterols. Cakes and aromatic water also presented high levels of proteins, fibers, sugars and phenols. These residues revealed interesting antioxidant and antibacterial activities. These results emphasized the potential use of cumin in a biorefinery concept, with a multi-purpose industrial process. In addition, large differences were observed between the four geographical origins for phytochemical contents and compositions. These findings highlight the perspectives for developing selection programs for nutritional traits and industrial interests. All obtained results validate the health promoting effect of cumin composition as well as its industrial importance along with the residues.

Effect of Surface Modification of H+‐Mordenite on the Isomerization of Oleic Acid into Branched‐Chain Isomers

AbstractRecent research studies have shown that oleic acid can be isomerized to saturated C18 branched‐chain fatty acids through H+‐Mordenite with modest yields (approximately 80 wt.%). The dimensions of tetraethoxysilane (TEOS) (10.3 Å) and triphenylphosphine (TPP) (11.4 Å) are larger than the H+‐Mordenite zeolite, which has a two‐dimensional 8‐member ring (MR) (2.6 Å × 5.7 Å) and 12‐MR (6.5 Å × 7.0 Å) framework. TEOS and TPP are incapable of entering into the internal channels of zeolite, however, they have the ability to poison the acids on the external surface of the H+‐Mordenite. The acidic sites of the specified pore can be selectively catalyzed but most of the active centers on the external surface are deactivated. In this study, all samples were characterized using X‐ray Diffractometry (XRD), scanning electron microscope (SEM), Brunner–Emmet–Teller (BET) measurements, thermogravimetry (TG), NH3‐TPD, and 1H MAS NMR. 2,4,6‐Trimethylpyridine was used for the characterization of the external acidic sites. With TEOS (1 wt.%) and 0.1 mol L−1 TPP‐modified H+‐Mordenite, the Bronsted acid sites on the external surface were reduced by 92.7% and the dimers were reduced from 16.19 wt.% to as low as 4.14 wt.% with 90.09 wt.% yield of saturated C18 branched‐chain fatty acids.

Computational and experimental research on mechanism of cis/trans isomerization of oleic acid

The harm of trans-fatty acids to health has aroused public concern. It is believed that the main source of trans-fatty acids in diets is the isomerization of unsaturated fatty acids in edible oils during cooking. However, the information on the isomerization mechanism is very limited. In this paper, we used oleic acid, an unsaturated fatty acid, as a simplified model for edible oil and investigated the mechanism of cis/trans isomerization by computation and experiments. The computational results show that Rc-O-O-H is a very important intermediate, and the cleavage of O-O bond in Rc-O-O-H is the rate-controlling step during the cis/trans isomerization. Using the ATR-FTIR measurements, the contents of elaidic acid were measured quantitatively in sites. The experimental results indicate that the cis/trans isomerization of oleic acid can occur obviously only under oxidizing condition when the temperature is higher than 120 °C.

Comparison of the effects of major fatty acids present in the Mediterranean diet (oleic acid, docosahexaenoic acid) and in hydrogenated oils (elaidic acid) on 7-ketocholesterol-induced oxiapoptophagy in microglial BV-2 cells

Increased levels of 7-ketocholesterol (7KC), which results mainly from cholesterol auto-oxidation, are often found in the plasma and/or cerebrospinal fluid of patients with neurodegenerative diseases and might contribute to activation of microglial cells involved in neurodegeneration. As major cellular dysfunctions are induced by 7KC, it is important to identify molecules able to impair its side effects. Since consumption of olive and argan oils, and fish is important in the Mediterranean diet, the aim of the study was to determine the ability of oleic acid (OA), a major compound of olive and argan oil, and docosahexaenoic acid (DHA) present in fatty fishes, such as sardines, to attenuate 7KC-induced cytotoxic effects. Since elaidic acid (EA), the trans isomer of OA, can be found in hydrogenated cooking oils and fried foods, its effects on 7KC-induced cytotoxicity were also determined. In murine microglial BV-2 cells, 7KC induces cell growth inhibition, mitochondrial dysfunctions, reactive oxygen species overproduction and lipid peroxidation, increased plasma membrane permeability and fluidity, nuclei condensation and/or fragmentation and caspase-3 activation, which are apoptotic characteristics, and an increased LC3-II/LC3-I ratio, which is a criterion of autophagy. 7KC is therefore a potent inducer of oxiapoptophagy (OXIdation+APOPTOsis+autoPHAGY) on BV-2 cells. OA and EA, but not DHA, also favor the accumulation of lipid droplets revealed with Masson’s trichrome, Oil Red O, and Nile Red staining. The cytotoxicity of 7KC was strongly attenuated by OA and DHA. Protective effects were also observed with EA. However, 7KC-induced caspase-3 activation was less attenuated with EA. Different effects of OA and EA on autophagy were also observed. In addition, EA (but not OA) increased plasma membrane fluidity, and only OA (but not EA) was able to prevent the 7KC-induced increase in plasma membrane fluidity. Thus, in BV-2 microglial cells, the principal fatty acids of the Mediterranean diet (OA, DHA) were able to attenuate the major toxic effects of 7KC, thus reinforcing the interest of natural compounds present in the Mediterranean diet to prevent the development of neurodegenerative diseases.

Identification of the oleic acid ethanolamide (OEA) isomer cis-vaccenic acid ethanolamide (VEA) as a highly abundant 18:1 fatty acid ethanolamide in blood plasma from rats and humans.

The endocannabinoid system is important in various physiological pathways, especially the regulation of food intake. It consists of endocannabinoids like 2-arachidonoyl-glycerol (2-AG) or the fatty acid ethanolamide archachidonoyl-ethanolamide (AEA) with binding affinity to cannabinoid receptors. Further, fatty acid ethanolamides (FAEAs) influence the endocannabinoid system without affecting cannabinoid receptors by using independent physiological pathways. Among FAEAs, oleic acid ethanolamide (OEA) gained importance because of its promising ability to reduce food intake. By ultrahigh-performance liquid chromatography-electrospray ionization-tandem mass spectrometry (UHPLC-ESI-MS/MS), we detected a chromatographically separated molecule in plasma samples from rats and humans with identical mass and fragmentation patterns as those of OEA. Via synthesis and extensive analysis of ethanolamides of different cis/trans- and position isomers of oleic acid (cis9-18:1), we could identify the unknown molecule as vaccenic acid (cis11-18:1) ethanolamide (VEA). In this study we identified VEA as the most abundant 18:1 FAEA in rat plasma and the second most abundant 18:1 FAEA in human plasma.

Petroselinic acid purification and its use for the fermentation of new sophorolipids

Petroselinic acid, a positional isomer of oleic acid, was isolated from the vegetable oil of Coriandrum sativum fruits. This uncommon fatty acid was subsequently used as substrate for sophorolipid fermentation with a Starmerella bombicola lactone esterase overexpression (oe sble) strain. A petroselinic acid based diacetylated sophorolipid lactone was obtained in high purity without incorporation of de novo synthesized fatty acids such as oleic acid. A total production of 40 g/L was obtained. The petroselinic acid based sophorolipid lactone was subsequently hydrolyzed towards the petroselinic acid based sophorolipid acid. For both compounds, their critical micelle concentration (CMC) and corresponding surface tension were compared to their oleic acid based counterparts. Both petroselinic acid based sophorolipids displayed a much lower CMC value than their oleic acid based counterparts, although their minimal surface tension was the same. Besides, the sophorolipid fermentation product was chemically modified towards a novel C12 sophorolipid aldehyde. This derivative constitutes an interesting building block for further modification towards new-to-nature sophorolipids with high potential for self-assembly applications.Electronic supplementary materialThe online version of this article (doi:10.1186/s13568-016-0199-7) contains supplementary material, which is available to authorized users.

Techno-Economic Analysis of an Improved Process for Producing Saturated Branched-Chain Fatty Acids

Methyl-branched fatty acids produced by isomerization of oleic acid (‘isostearic’ acids (IA)) are industrially useful products with excellent thermostabilities and lubricities and reduced freezing points relative to stearic acid. They have potential utility as biodiesel or a biodiesel additive imparting improved low temperature fluidity. We present a techno-economic model for industrial scale production of isostearic acid by zeolite-catalyzed isomerization. A catalyst regeneration loop allowing 20 reaction cycles was included. Use of catalyst for 15 or more reaction cycles reduced process cost by 51% vs. a single use reaction format. However, with a best-case predicted production cost of $2.375/kg ($1.080/lb), further process cost reductions will be required before use of IA esters as high percentage blend components of biodiesel is economically feasible.

Trans-11 18:1 Vaccenic Acid (TVA) Has a Direct Anti-Carcinogenic Effect on MCF-7 Human Mammary Adenocarcinoma Cells

Trans vaccenic acid (TVA; trans-11 18:1) is a positional and geometric isomer of oleic acid and it is the predominant trans isomer found in ruminant fats. TVA can be converted into cis-9, trans-11 conjugated linoleic acid (c9, t11-CLA), a CLA isomer that has many beneficial effects, by stearoyl CoA desaturase 1 (SCD1) in the mammary gland. The health benefits associated with CLA are well documented, but it is unclear whether trans fatty acids (TFAs) from ruminant products have healthy effects. Therefore, the effects of TVA on the proliferation of MCF-7 human breast adenocarcinoma cells and MCF-10A human breast epithelial cells were investigated in the present study. Results showed that TVA inhibited the proliferation of MCF-7 cells but not MCF-10A cells by down-regulating the expression of Bcl-2 as well as procaspase-9. In addition, the suppressive effect of TVA was confirmed in SCD1-depleted MCF-7 cells. Our results suggested that TVA exerts a direct anti-carcinogenic effect on MCF-7 cells. These findings provided a better understanding of the research on the anti-carcinogenic effects of TVA and this may facilitate the manufacture of TVA/c9, t11-CLA fortified ruminant products.

Assessment of Trans Fatty Acid Content in Widely Consumed Snacks by Gas Chromatography in a Developing Country

Trans fatty acids have adverse effects on health, so knowledge of their contents in foods would enable people to make informed food choices. TFA levels when not available in food composition tables make it difficult to estimate dietary intake. With the aim to analyze and identify the actual amount of trans fatty acid present in selected Indian fast food items, triplicate samples of six commonly consumed snacks as well as the oil used for preparing the same were collected from three different places. The separation of fatty acid was done using gas chromatography. Trans fatty acid isomers of oleic acid, linoleic acid and linolenic acid were identified in all food items. The predominant trans fatty acid present in all the food items was elaidic acid (18:1t9). The total trans fatty acids in different food items ranged from almost negligible to as high as 14.58 g/100g food. Different amount of TFA was found in same food category sourced from different outlets which is a challenge in making regulations aimed at TFA reduction so as to decrease health risk.

Reactivity of Thiyl Radicals Generated from Thiomethoxide and Dimethyldisulfide in Microheterogeneous Media

Abstract: Sodium thiomethoxide and dimethyldisulfide will be shown to be convenient sources of methyl thiyl radicals for effecting the cis-trans double bond isomerization of oleic acid to elaidic acid residues arranged in phospholipid bilayers of the microheterogeneous aqueous environment of liposomes. The methods used for methyl thiyl radical generation encompass radiolytic and photochemical meth-ods. The convenience of these methyl thiyl radical sources will be interpreted in terms of the turn-over numbers in the radical chain cis-trans isomerization reaction of unsaturated lipids. Keywords: Methyl thiyl radicals, Sodium thiomethoxide, Dimethyldisulfide, cis-trans isomerization. INTRODUCTION Thiyl radicals have been extensively studied in the context of free radical double bond isomerization. Fig. ( 1 ) shows the reaction mechanism of free thiyl radical RS• double bond isomerization that consists of a reversible addition of radical RS• to the double bond. The regeneration of the double bond is obtained by
-elimination of RS• and the result is in favor of the

Plasma and Brain Fatty Acid Profiles in Mild Cognitive Impairment and Alzheimer's Disease

Alzheimer's disease (AD) is generally associated with lower omega-3 fatty acid intake from fish but despite numerous studies, it is still unclear whether there are differences in omega-3 fatty acids in plasma or brain. In matched plasma and brain samples provided by the Memory and Aging Project, fatty acid profiles were quantified in several plasma lipid classes and in three brain cortical regions. Fatty acid data were expressed as % composition and as concentrations (mg/dL for plasma or mg/g for brain). Differences in plasma fatty acid profiles between AD, mild cognitive impairment (MCI), and those with no cognitive impairment (NCI) were most apparent in the plasma free fatty acids (lower oleic acid isomers and omega-6 fatty acids in AD) and phospholipids (lower omega-3 fatty acids in AD). In brain, % DHA was lower only in phosphatidylserine of mid-frontal cortex and superior temporal cortex in AD compared to NCI (-14% and -12%, respectively; both p < 0.05). The only significant correlation between plasma and brain fatty acids was between % DHA in plasma total lipids and % DHA in phosphatidylethanolamine of the angular gyrus, but only in the NCI group (+0.77, p < 0.05). We conclude that AD is associated with altered plasma status of both DHA and other fatty acids unrelated to DHA, and that the lipid class-dependent nature of these differences reflects a combination of differences in intake and metabolism.

Ruminant and industrial sources of trans-fat and cardiovascular and diabetic diseases

The various positional isomers of oleic acid (18 : 1Δ9c or 9c-18 : 1) may have distinct biological effects. Detrimental effects of consumption of industrial trans-fatty acids (TFA) (elaidic acid; 18 : 1Δ9t) from partially hydrogenated vegetable oils on CVD risk factors are well documented. In addition, epidemiological data suggest that chronic consumption of industrial sources of TFA could alter insulin sensitivity and predispose for type 2 diabetes. However, intervention studies on this issue have remained inconclusive. Moreover, very little information is available on the effect of natural sources of TFA (vaccenic acid; 18 : 1Δ11t) coming from dairy products and ruminant meat on the development of CVD and type 2 diabetes. The review focuses on the impact of the consumption of ruminant TFA in relation to cardiovascular risk factors, inflammation and type 2 diabetes.

Distribution of unusual fatty acids in the mesocarp triacylglycerols of maturing sea buckthorn fruits

The pattern of distribution of X-FAs among individual positional species of the X-triacylglycerols (X-TAGs) in the sea buckthorn (Hippophae rhamnoides L.) mesocarp oil by the 80th, 90th, and 105th day after pollination (DAP) was investigated. The X-FAs comprised oleic acid (O) as well as unusual FAs, viz. hexadecenoic (H), palmitolinoleic (Pl), and cis-vaccenic acid (V). During mesocarp growth, the number of X-TAG species decreased dramatically as a result of their metabolism, but their proportion in the total TAGs remained constant. H-TAGs predominating in the oil were similar to total TAGs in their composition and the pattern of their dynamics during maturation. As regards minor Pl-TAGs, there was a tendency for an increase in the level of species including palmitolinoleic acid in the middle (sn-2) position of their molecules. Throughout the entire process of fruit maturation, oleic acid was by 98.0–98.8% concentrated in the sn-2 position of O-TAGs. At the same time, cis-vaccenic acid, a Δ11-positional isomer of oleic acid, was predominantly incorporated in the side positions of V-TAGs, and its 98.1% concentration in these positions was achieved only by the 105th DAP. A virtually absolute selectivity of the distribution of oleic and cis-vaccenic acids in TAGs was found here for the first time. Discussed are the possible physicochemical and biochemical factors of a highly selective incorporation of these FAs in the sea buckthorn TAGs, the pathways of enzymatic biosynthesis of O- and V-TAGs, the metabolic role of discrimination of incorporation of some FA species in the glycerol residue of glycerolipids, and the causes for the disappearance of some TAG species during maturation.

Human health benefits of vaccenic acid

The health risks associated with consumption of diets high in trans fats from industrially produced hydrogenated fats are well documented. However, trans fatty acids are not a homogeneous group of molecules, and less is known about the health effects of consuming diets containing vaccenic acid (VA), a positional and geometric isomer of oleic acid, the predominant trans isomer in ruminant fats. The presence of VA in industrial trans fats has raised the question of whether VA produces the same adverse health effects as industrially produced trans fats. VA is also the major trans fat in ruminant fats, and questions have arisen as to whether consuming this trans fat has the same effects on health risk. The purpose of this paper is to critically review the published studies in humans, animals, and cell lines. Epidemiological, but not rodent, studies suggest that VA intake or serum concentrations may be associated with increased cancer risk. However, epidemiological, clinical, and rodent studies to date have not demonstrated a relationship with heart or cardiovascular disease, insulin resistance, or inflammation. VA is the only known dietary precursor of c9,t11 conjugated linoleic acid (CLA), but recent data suggest that consumption of this trans fat may impart health benefits beyond those associated with CLA.