Linoleic acid, 439 Table

Sunflower oil with high palmitic, stearic, oleic, or linoleic acid (Table 13). 

Fatty Acid Composition The fatty acid content of RBO is mainly palmitic, oleic, and linoleic acid (Table 24). The low linolenic acid content of RBO makes it stable to oxidation. Several studies reported variations in fatty acid composition of RBO (90, 95-96). Goffman et al. (90) studied the fatty acid composition of 204 rice varieties. Genotype and environment significantly affected stearic, oleic, linoleic, and linolenic acids but not palmitic acid content of the RBO. The ratio of saturated to unsaturated acid ratio (S/U) was correlated to the palmitic acid content of the oil. Japonica lines had low palmitic acid content and S/U ratio, whereas Indica lines were characterized by high palmitic acid content and high S/U ratio (90). 

Traditional sunflower oil has a high linoleic acid content. This varies, but the oil from most common varieties contain about 65-70% linoleic acid. In contrast to this are the high-oleic (> 80% oleic acid and only 5-9% linoleic acid) and mid-oleic varieties (55-75% oleic acid and 15-35% linoleic acid). Table 5.8 shows the typical fatty acid composition of these three types of sunflower... 

The data in Table 1 show that when the oxidation of dilinolein, methyl linoleate, and monolinolein was followed in the presence of linoleic acid, their rates of oxidation were reduced relative to that of linoleic acid (Table 1, entries 1-3). 

The oil from the seed is a by-product of the juice processing industry in many countries. The seed furnishes a pale yellow oil with an average yield of 20%. The four major fatty acids are palmitic, stearic, oleic and linoleic acids (Table 5.10) with a total unsaturation level of 89.8% (Assuncao et al., 1984). 

Poppy Oil is very rich in linoleic acid (Table 14.11). The cold-pressed oil from flawless seeds is colorless to fight yellow and can be used directly as an edible oil. 

Moulds belonging to the Mucorales family produce GLA as their only 18 3 acid. Commercial processes for GLA production have been developed in Japan based on Mortierella isabelina and in the UK based on Mucor javanicus. The UK production is now discontinued following a change in ownership of the producer company. These products differ from the seed oils in their higher levels of saturated and monoene acids and their lower level of linoleic acid (Table 4). This makes the mould-derived oils more suitable as a source of pure... 

As expected, the Hnolenic acid was mostly located on the Sn-2 position. It was the same for linoleic acid (Table 1). 

Polyunsaturated fatty acids are ultimately derived from plants, seed, leaves, and phytoplankton. Terrestrial food chains (i.e., edible plants and animal fat) contain primarily linoleic acid (Table 3, Fig. 2), an polyunsaturated fatty acid, and only very small amounts of cu-3 polyunsaturated fatty acids (nearly exclusively CK-linolenic acid). Fatty acids in land plants are not chain-elongated above the 18-carbon level. In mammalians, the polyunsaturated 18-carbon eu-6 linoleic acid will be converted to arachidonic acid (20 4, (o-6) by chain elongation and desaturation. As the three major families of unsaturated fatty acids (oleic acid, (o-9 linoleic acid, cu-6 and linolenic acid, cu-3) (Table 3) are metabolically nearly inconvertible in mammalians, phytoplankton and algae, which synthesize eicosapentaenoic acid (20 5, cu-3) and docosahexaenoic acid (22 6, cu-3), are the principal sources of the major cu-3 fatty acids. Only a-linolenic acid from vegetable oils is in principle able to be partially converted to eicosapentaenoic acid ([26] Fig. 2). 

Separation of Fatty Acids. Tall oil is a by-product of the pulp and paper manufacturiag process and contains a spectmm of fatty acids, such as palmitic, stearic, oleic, and linoleic acids, and rosia acids, such as abietic acid. The conventional refining process to recover these fatty acids iavolves iatensive distillation under vacuum. This process does not yield high purity fatty acids, and moreover, a significant degradation of fatty acids occurs because of the high process temperatures. These fatty and rosia acids can be separated usiag a UOP Sorbex process (93—99) (Tables 8 and 9). 

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 polyunsaturated aliphatic monocarboxyhc acids having industrial significance include sorbic, linoleic, linolenic, eleostearic, and various polyunsaturated fish acids (Table 3). Of these, only sorbic acid (qv) is made synthetically. The other acids, except those from tall oil, occur naturally as glycerides and are used mosdy in this form. 

Tall oil fatty acids consist of resin acids (25% to 30%) and of a mixture of linolic acid, conjugated Cig fatty acids (45% to 65%), oleic acid (25% to 45%), 5,9,12-octadecatrienic acid (5% to 12%), and saturated fatty acids (1% to 3%). Resin acids are abietinic acid, dehydroabietic acid, and others. Properties of fatty acids are shown in Table 6-1. 

In general for the C20 series, maximal activity is achieved with amides of arachidonic acid (1) [81], mead acid (199) [149], and dihomo-y-linoleic acid (200) [150] (see Table 6.18). Decreasing the unsaturation (201), (202), or abolishment of the n-pentyl chain (203) [150] led to less active or inactive compounds. Variable results were seen with longer chains. The C22 4 n-6 analogue (204) is as active as AEA (1) whereas the C22 6 n-3 analogue (205) is less active than the C20 5 n-3 analogue (203) [150]. Replacement of the double bonds with triple bonds (206) resulted in loss of activity [150] (see Table 6.18). Forcing the fatty acid chain into a hairpin conformation by cyclisation (207) also resulted in inactive compounds [151]. 

As mentioned in the introduction, 3-hydroxy fatty acids with functional groups can also be incorporated in poly(3HAMCL). Table 2 illustrates this with many examples of alkenes, 3-hydroxyalkenoic acids, and substituted 3-hy-droxyalkanoic acids that are readily integrated in poly(3HAMCL). Long chain fatty acids have also been used successfully as substrates for poly(3HAMCL) production. De Waard et al. [44] used oleic acid and linoleic acid to produce... 

Polyunsaturated fatty acids are characterized by a large number of C = C double bonds in their hydrocarbon chain. Stearic acid has no C = C double bonds and therefore is not unsaturated, let alone polyunsaturated. But eleostearic acid has three C = C double bonds and thus is polyunsaturated. Polyunsaturated fatty acids are recommended in dietary programs since saturated fats are linked to a high incidence of heart disease. Of the lipids listed in Table 28-2, safflower oil has the highest percentage of unsaturated fatty acids, predominately linoleic acid, an unsaturated fatty acid with two C=C bonds. 

TABLE 13. 13C NMR chemical shift values of conjugated linoleic acid isomers... 

As shown in Table 1, the acyl moiety of cardiolipin is comprised almost entirely of unsaturated fatty acids. Other membrane phospholipids such as phosphatidyl choline and phosphatidyl ethanolamine contain 1(M0 mol of saturatedfatty acids such as palmitic acid (Ci6 0) and stearic acid (Ci8 0) per 100 mol of total fatty acids. In particular,linoleic acid (Cl8 2) is the most abundant polyunsaturated fatty acid consisting of 80 mol%, linolenic acid (Cl8 3) 8 mol%, and oleic acid (Ci8 i) 6 mol%. Therefore, by using a commercially available cardiolipin purified from bovine heart mitochondria, we characterized auto-oxidation products by reverse phase HPTLC and reverse phase HPLC. 

The common fatty acids have a linear chain containing an even number of carbon atoms, which reflects that the fatty acid chain is built up two carbon atoms at a time during biosynthesis. The structures and common names for several common fatty acids are provided in table 18.1. Fatty acids such as palmitic and stearic acids contain only carbon-carbon single bonds and are termed saturated. Other fatty acids such as oleic acid contain a single carbon-carbon double bond and are termed monounsaturated. Note that the geometry around this bond is cis, not trans. Oleic acid is found in high concentration in olive oil, which is low in saturated fatty acids. In fact, about 83% of all fatty acids in olive oil is oleic acid. Another 7% is linoleic acid. The remainder, only 10%, is saturated fatty acids. Butter, in contrast, contains about 25% oleic acid and more than 35% saturated fatty acids. 

Table 2. Conjugated Dienoic Isomers of linoleic Acid in other Dairy Products ...

Table 9.2 Concentration of conjugated linoleic acid (CLA) isomers in selected foods (modified from Ha, Grimm and Pariza, 1989)...

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