Fatty acids elaidic

Anderson, A. K, Bignell, W. E. Chakraborty, P. (2011). Negative effect of industrial produced trans fatty acid (elaidic acid) on pregnancy outcome and early postpartum life. Agro Food Industry Hi-Tech, 22(5 , 10-2. 

The carbon chains of samrated fatty acids form a zigzag pattern when extended, as at low temperamres. At higher temperatures, some bonds rotate, causing chain shortening, which explains why biomembranes become thinner with increases in temperamre. A type of geometric isomerism occurs in unsaturated fatty acids, depending on the orientation of atoms or groups around the axes of double bonds, which do not allow rotation. If the acyl chains are on the same side of the bond, it is cis-, as in oleic acid if on opposite sides, it is tram-, as in elaidic acid, the tram isomer of oleic acid (Fig-... 

Figure 14-5. Geometric isomerism of A , 18 1 fatty acids (oleic and elaidic acids).

Fig. 12.1 Conversion of fatty acid methyl esters (FAMEs) methyl oleate ( ) and methyl elaidate ( ) vs. reaction time over Ti-MCM-41 (a) and overTi-Si02 (b). (Adapted from [49]).

Some of the unsaturated fats ingested by ruminants are partially hydrogenated by bacteria in the rumen. In consequence, milk fat, dairy products, as well as beef and mutton fat, also contain small amounts of trans isomers, about 2 to 9%. However, in fat from ruminants the main trans fatty acid is vaccenic (18 1 t 11), while in hydrogenated fats it is elaidic (18 1 t 9) (Figure 13.14). 

BETA derivatives of C9-C22 saturated fatty acids, as well as the Cig unsaturated acids, oleic and elaidic, were prepared and evaluated in the previous publication (11). Hydrophobicity determination, via contact angle measurements, proved to be nondiscriminatory and, therefore, a more meaningful test, the sand penetration test was devised. 

Ci6j Cjg saturated fatty acids, Armak Industrial Chemicals Division (Chicago, IL) oleic acid, A. Gross Company (Newark, NJ) elaidic acid, laboratory preparation (12) tallow, Corenco Corporation (Philadelphia, PA) (titer, t =... 

Figure 11.10 Structure of ds-octadecenoic and trans-octadecenoic add (an example o/cis-trans isomerism). The common name for trans-octadecenoic acid is elaidic acid it is one of the few naturally occurring trans fatty acids. The common name for c/s-octadecenoic acid is oleic acid. Note that the two hydrocarbon chains are separated by the double bond which prevents rotation of the position of the two chains. The structure of the trans fatty acid is biochemically unusual and therefore biochemically excluded. ...

Free fatty acids are separable by GC by the inclusion of phosphoric acid in the packing so, for HPLC analysis, the phosphoric acid or other equivalent strong acid is included in the mobile phase. On a SUPELCOSIL LC 18 column, a model mixture of free fatty acids was separated with a mobile phase containing tetrahydrofuran, acetonitrile, water, and phosphoric acid (6 64 30 0.1) at pH 2 (Fig. 1) (15). Oleic and elaidic acids, palmitoleic and palmitelaidic acids, and linoleic and linoelaidic acids were well separated, but margarine fatty acids presented a difficult problem. Ultraviolet detection of 220 nm was used to prepare this chromatogram. 

Fig. 1 HPLC of free fatty acids. Column SUPELCOSIL LC 18. 25 cm X 4.6-mm ID. (5fi) mobile phase tetrahydrofuran/acetonitrile/0.1% phosphoric acid, pH 2.2 (21.6 50.4 28.0) flow rate 1.5 ml/min temperature 35°C detection at 220 nm sample concentration 1-2 mg/ml per component. 16 1 (cis) = cis-9-hexadecenoic acid (cis-palmitoleic acid) 16 1 (trans) = trans-9-hexadecenoic acid (trans-palmitoleic acid) 18 0 = octadecanoic acid (stearic acid) 18 1 (cis) = cw-9-octadecenoic acid (oleic acid) 18 1 (trans) = trans-9-octadecenoic acid (elaidic acid) 18 2 (cis) = cis-9-cis-12-ctadecadienoic acid (linoleic acid) 18 2 (trans) = trans-9-trans-12-octadecadienoic acid (linolelaidic acid) 18 3 (cis) = cis-9-cis-2-cis-15-octadecatrienoic acid (linolenic acid).

The hardening effect of fatty oil isomerization processes is limited by the fact that cis-trans conversion of the double bond of mono-unsaturated fatty acids is an equilibrium reaction in the case of oleic and elaidic acid esters the equilibrium mixture consists of 67% elaidic acid and 33% oleic acid this equilibrium ratio is practically independent of the isomerization temperature77. 

Body temperatures are approximately 37°C/ 98.6°F for humans 38.5-39.5°C/101-103°F) for domestic animals and 40.5-41.5°C/ 105—107°F) for poultry. As shown in Table 34.1, the longest saturated fatty acid that is fluid at these temperatures is caproic (Cl0 0). All longer saturated fatty acids must be accompanied by lower melting unsaturated fatty acids as in a TAG structure to be fluid. The C18 oleic acid (c-9-octadecenoic acid) has a melting point of 16.3°C, the trans isomer elaidic acid (t-9-octadecenoic acid) melts at 43.7°C, and the biohydrogenated product trans-vaccenic acid (t- 1-octacedenoic acid) melts at 44°C.40... 

To describe the composition of fatty acids it is sometimes useful to use a shorthand designation. In this convention the composition of a fatty acid can be described by two numbers separated by a colon. The first number indicates the number of carbon atoms in the fatty acid chain, the second number indicates the number of double bonds. Thus, 4 0 is short for butyric acid, 16 0 for palmitic acid, 18 1 for oleic acid, etc. The two numbers provide a complete description of a saturated fatty acid. For unsaturated fatty acids, information about the location of double bonds and their stereo isomers can be given as follows oleic acid (the cis isomer) is 18 lc9 elaidic acid (the... 

Although naturally occurring unsaturated fatty acids have the Z configuration, elaidic acid, a Cis fatty acid having an E... 

Non-lauric CBS consists of fractions of hydrogenated oils soybean, cotton, corn, peanut, safflower, and sunflower oils. These oils are hydrogenated under selective conditions to promote the formation of trans-fatty acids, thereby increasing the solid contents considerably. The melting point of oleic acid—the cw-configura-tion—is 14°C, whereas the isomer elaidic acid melts at 51.5°C. 

Triglycerides containing saturated fatty acids easily form a compact structure, when placed together, and form a solid at room temperature. Where the fatty acids contain double bonds in the usual cis conformation, the cis double bonds create bends in the fatty acid, which impair close packing, and result in a liquid (oil). Where the fatty acids are in the trans conformation, the ability to pack closely is in between triglycerides with saturated and cis fatty acids. Oleic acid, a cis fatty acid, is 18 1, as noted earlier. The corresponding 18 1 trans fatty acid is called elaidic acid. Elaidic acid is abbreviated as trans 18 1. 

The fat in beef, mutton, milk, and cheese contains 2-8% trans fatty acids. These naturally occurring trans fatty acids are formed in the rumen of the stomach (of ruminants) by the action of bacterial enzymes. Most of the trans fatty acids of the diet arise from the industrial hydrogenation of food oils. During this process, most of the unsaturated cis fatty acids are converted to saturated fatty acids, but a fraction is converted to trans fatty acids. In relation to all fatty acids present in the indicated food, salad oils contain 8-17% trans fatty acid, shortening contains 14-60%, and margarines 16-70% (Simopoulos, 1996). Overall, about 6% of our dietary fatty acids are trans fatty acids, where most of these are elaidic acid (McKeigue, 1995). 

Figure 2. Calculated vs. observed free energies of binding for DHFR complexes (circles), the arabinose complex with arabinose binding protein (triangle), the lysine complex with lysine binding protein (diamond), the complexes of stearate and elaidate with muscular fatty acid binding protein (squares) and the complexes of retinol, retinoic acid, n-ethyl-retinamide and fenretinide with bovine plasma RBP (stars).

Fig. (2). double bond configuration in fatty acid chains, (a) stearic acid (Cis-o) saturated (b) oleic acid (C jjin-9) monounsaturated containing one cisi-double bond, (c) elaidic acid (Cis i) monounsaturated containing one trans-doubie bond... 

Figure 7. Methyl esters of unsaturated fatty acids as resolved on the 25%-cyanopropyl-25%-phenyl methyl siloxane DB-225. Split Injection to a 30m x 0.25mm column coated with a 0.25 m bonded film, hydrogen carrier at 46cm/sec, isothermal at 200 °C. Components 1, 14 1 methyl myristoleate 2, 16 1 trans methyl palmite-laidate 3, 16 1 cis methyl palmitoleate 4, 18 1 trans methyl elaidate 5, 18 1 cis methyl oleate 6, 18 2 trans methyl linolea-laidate 7, 18 2 cis methyl linoleate 8, 18 3 methyl linoleate ...

Materials. High purity saturated fatty acids, cis- and trans-A9-octa-decenoic acids (oleic and elaidic acids) and 12-hydroxystearic acid, were obtained from Applied Science Laboratories. Trans-3-octadecenoic acid... 

The acids (Figures 1 2) 95 and 99% oleic, 95% linoleic, 99% linolenic, 99% elaidic and cholic acids were obtained from chemical supply houses. Mixed rosin acids were a commercial product, Acintol R type S (2). Sodium salts of fatty acids were formed by electrometric titration of an aqueous-ethanol solution with sodium hydroxide, evaporated to dryness to remove ethanol and stored dry or as an aqueous stock solution. A sample of mixed rosin acids was assayed electrometrically with potassium hydroxide in benzene-ethanol. A stock solution was then prepared in water from a weighed quantity of Acintol R and the amount of sodium hydroxide calculated from the assay. Other materials were reagent grade chemicals. 

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