Triglycerides linoleic acid

Multiply unsaturated linolenic and linoleic acid residues make triglycerides more vulnerable to oxidative degradation than oleic acid which is relatively stable. It is therefore desirable to hydrogenate the most unsaturated residues selectively without production of large quantities of stearic (fully saturated) acid. The stepwise reduction of an unsaturated oil may be visualized as ... 

Lipids. Representative fatty acid compositions of the unprocessed triglyceride oils found in the four oilseeds are given in Table 4 (see Fats and FATTY oils). Cottonseed, peanut, and sundower oils are classified as oleic—linoleic acid oils because of the high (>50%) content of these fatty acids. Although the oleic and linoleic acid content of soybean oils is high, it is distinguished from the others by a content of 4—10% of linolenic acid, and hence is called a linolenic acid oil. 

The traditional major source for the nonionic surfactant industry is fatty acid triglycerides from both animal and vegetable sources as the saturated or unsaturated acids. The saturated acids include lauric acid (w-dodecanoic), myristic acid (n-tetradecanoic), palmitic acid ( -hexadecanoic),and stearic acid (n-octadecanoic). The unsaturated acids include oleic acid (Z-9-octadecenoic) and linoleic acid (Z,Z-9,12-octadecadienoic). Of the 200 non-ionic surfactants... 

RP-HPLC with nonaqueous solvents and UVD at 246 nm was developed for the determination of low level POVs of vegetable oils. These measurements are specific for conjugated diene peroxides derived from vegetable oils with relatively high linoleic acid content. These measurements may be supplemented by nonspecific UVD at 210 nm and ELSD for detection of all eluted species. The elution sequence of the triglycerides in a nonaqueous RP-HPLC is linearly dependent on the partition number of each species, Vp, which is defined as = Nq — 2Ni, where Nq is the carbon number and is the double bond number. In the case of hydroperoxides = Nq — 2Nd — Vhpo, where Vhpo is the number of hydroperoxyl groups in the molecule (usually 1 for incipient POV). For... 

Castor oil [CO Structure (4.3)] is a triglyceride of ricinoleic (12-hydroxyoleic) acid about 90% of the fatty acid portion of the molecule consists of ricinoleic acid and 10% in the form of non-hydroxy acids consisting largely of oleic and linoleic acids. Small amounts of stearic and dihydroxystearic acids are also found in some industrial grades. 

Linoleic acid and alpha-linoleic acid are essential fatty acids that are provided in any long-term parenteral nutrition by administering fat emulsions at least twice a week. Fatty acid deficiency is a common complication of severe end-stage liver disease. The ability of short-term intravenous lipid supplementation to reverse fatty acid deficiencies has been studied in patients with chronic liver disease and low plasma concentrations of fatty acids (914). Shortterm supplementation failed to normalize triglycerides. 

The carboxylic acids can be subdivided into nonvolatile fatty acids, volatile fatty acids, hydroxy acids, dicarboxylic acids, and aromatic acids (Fig. 3). The nonvolatile fatty acids are molecules with more than five carbon atoms, such as stearic and palmitic acids, which are the degradation products of fats and triglycerides. Three different 18-C fatty acids that are important constituents of plants include oleic and linoleic acids that are abundant in plant seeds, and linolenic acid, which is abundant in plant leaves. Volatile fatty acids are short-chain molecules with one to five carbon atoms, such as acetic and valeric acid, associated with anaerobic metabolism. The hydroxy-acids are common intermediates in biochemical pathways, including the tricarboxylic acid cycle. The excretion of hydroxyacids by algae, such as the... 

A quantitative conversion has been described within 4 h with 40 bar of pressure and at 100°C. The polyunsaturated fatty acids like linoleic acid were hydroformylated manifold. If RhC P O is employed, soybean oil cannot be hydroformylated because only the isomerization of conjugated fatty acids is obtained [24]. The direct processing of a fat without cleavage of the triglyceride is attractive for several applications. 

A remarkable feature of lipids, either vegetal or animal, is that they share the same fatty acids in triglycerides in the range C12-C20 (Table 14.3). However, there are significant differences in composition. Thus, soybean, sunflower and rapeseed oils are all based on C18 acids, the first two being richer in unsaturated linoleic acid, which could introduce a problem of stability with respect to oxidation. The palm oil has an important amount of C16 acid. Coconut oil is given as an example of Cl2-04 rich oil. As in palm oil the composition of tallow spreads over Cl6-08 acids. 

In human adipose tissue, palmitoyl-CoA is usually used in the first glycerol-3-phosphate acylation reaction. The next two acyl residues are normally unsaturated fatty acids oleic acid and, less commonly, linoleic acid. Triglyceride biosynthesis is stimulated by insulin, most likely via its activation of lipoprotein lipase and its activity in moving glucose into the cells. 

Morrison, I.M., Hawke, J.C. 1977a. Triglyceride composition of bovine milk fat with elevated levels of linoleic acid. Lipids. 12, 994-1004. 

Lipoxygenase is reported to have a pH optimum of about 9. However, these values are determined with linoleic acid as substrate, and in natural systems the substrate is usually present in the form of triglycerides. The enzyme has a molecular weight of... 

As linoleic, oleic, and palmitic fatty acid account for over 90% of the fatty acids in cottonseed oil, most of the triglycerides contain some combination of these fatty acids. Table 7 lists the possible combinations of composition and position of saturated, oleic, and linoleic acids in cottonseed oil triglycerides. These ten types of triglycerides account for 92% of the total triglycerides found (73). The predominant type is SLL (saturated and linoleic fatty acid in the 1, 2, and 3 positions, respectively), which accounts for over 22 mol% of the triglyceride molecules. 

Free fatty acids, whose levels are generally raised by insulin or alcohol, influence the rate of VLDL synthesis and hence the concentration of triglycerides. About 16 g glycerol, which are mainly utilized in the liver, are released daily by lipolysis, and about 120 g free fatty acids are made available for generating energy in the heart and skeletal musculature (75%) as well as in the liver itself (25%o). These free fatty acids are bound in the plasma to albumin (50%) and lipoproteins (50%). Their extremely short plasma half-life of approx. 2 minutes emphasizes their high metabolic activity. Fatty acids are present in the plasma in saturated (no double bond) and unsaturated (various numbers of double bonds) forms. Essential fatty acids cannot be synthesized by the body, which means they must be obtained from food intake. The most important ones are multiple unsaturated fatty acids such as linolic acid (Cis-fatty acid, 2 double bonds), linolenic acid (Ci8-fatty acid, 3 double bonds), and arachidonic acid (C2o-fatty acid, 4 double bonds). Their prime function is to act as precursors for the synthesis of eicosan-oids. (s. fig. 3.10)... 

As previously mentioned, the triglycerides found in biomass are esters of the triol, glycerol, and fatty acids (Fig. 3.6). These water-insoluble, oil-soluble esters are common in many biomass species, especially the oilseed crops, but the concentrations are small compared to those of the polysaccharides and lignins. Many saturated fatty acids have been identified as constituents of the lipids. Surprisingly, almost all the fatty acids that have been found in natural lipids are straight-chain acids containing an even number of carbon atoms. Most lipids in biomass are esters of two or three fatty acids, the most common of which are lauric (Cn), myristic (Cu), palmitic (Cia), oleic (Cis), and linoleic (Cis) acids. Palmitic acid is of widest occurrence and is the major constituent (35 to 45%) of the fatty acids of palm oil. Lauric acid is the most abundant fatty acid of palm-kemel oil (52%), coconut oil (48%), and babassu nut oil (46%). The monounsaturated oleic acid and polyunsaturated linoleic acid comprise about 90% of sunflower oil fatty acids. Linoleic acid is the dominant fatty acid in com oil (55%), soybean oil (53%), and safflower oil (75%). Saturated fatty acids of 18 or more carbon atoms are widely distributed, but are usually present in biomass only in trace amounts, except in waxes. 

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