Major fatty acids linoleic

Com oil is composed of fatty acid esters with glycerol, known commonly as triglycerides. Typical com oil produced in the USA contains five major fatty acids linoleic 58.9% oleic 25.8% palmitic 11.0% stearic 1.7% and linolenic 1.1%. Com grown outside the USA yields com oil with lower linoleic, higher oleic, and higher saturated fatty acid levels. Corn oil also contains small quantities of plant sterols. 

High salt concentration did not delay lipogenesis during ripening seeds but delay anthesis date and did not seem to decrease drastically total lipids content. This finding could be related to the salt tolerance of Cotton plant. However low sodium chloride concentration (3g/l) stimulated oil synthesis. Sodium chloride reduced the content of the major fatty acid (linoleic acid) of Cotton seeds as it did for the principal olive fatty acid (oleic acid) (Marzouk et al. 1986). 

The major fatty acids present in plant-derived fatty substances are oleic acid (9-octadecenoic, C18 l), linoleic acid (9,12-octadecadienoic, C18 2) and the conjugated isomers thereof and linolenic acid (9,12,15-octadecatrienoic, C18 3) (Scheme 31.1). Their rates of oxygen absorption are 100 40 1, respectively, hence partial hydrogenation with consequent lowering of the iodine number would lead to a significant increase in oxidative stabihty, particularly when C18 3 is reduced. 

Rancidity measurements are taken by determining the concentration of either the intermediate compounds, or the more stable end products. Peroxide values (PV), thiobarbituric acid (TBA) test, fatty acid analysis, GC volatile analysis, active oxygen method (AOM), and sensory analysis are just some of the methods currently used for this purpose. Peroxide values and TBA tests are two very common rancidity tests however, the actual point of rancidity is discretionary. Determinations based on intermediate compounds (PV) are limited because the same value can represent two different points on the rancidity curve, thus making interpretations difficult. For example, a low PV can represent a sample just starting to become rancid, as well as a sample that has developed an extreme rancid characteristic. The TBA test has similar limitations, in that TBA values are typically quadratic with increasing oxidation. Due to the stability of some of the end-products, headspace GC is a fast and reliable method for oxidation measurement. Headspace techniques include static, dynamic and solid-phase microextraction (SPME) methods. Hexanal, which is the end-product formed from the oxidation of Q-6 unsaturated fatty acids (linoleate), is often found to be a major compound in the volatile profile of food products, and is often chosen as an indicator of oxidation in meals, especially during the early oxidative changes (Shahidi, 1994). 

Table II lists the increases for the four major fatty acids in the free fatty acid fraction. Collectively, palmitic (C. q), oleic (Cig.), linoleic (C g an< lin°lenic comprise greater...

Among fatty acids, linoleic acid was the major constituent (nearly 50%), followed by oleic ( 24%) and palmitic acids ( 15%). Table 20.4 gives the fatty acid composition of the seed oil of tamarind. Among sterols, betasitosterol constituted 66-72%, followed by campesterol (16-19%) and stigmasterol (Andriamanantena et al., 1983). 

Cashew (Anacardium occidentale). Toschi et al. (91) have given details of the fatty acids, triacylglycerols, sterols, and tocopherols in cashew nut oil. The major fatty acids are palmitic (9-14%), stearic (6-12%), oleic (57-65%), and linoleic (16-18%), and the major triacylglycerols are OOO, POO, OOSt, OOL, and POL. 

Melon Citrullus colocythis and C. vulgaris). This seed oil has been examined in terms of its fatty acids and phospholipids by Akoh and Nwosu (139). The major fatty acids in the total lipids are palmitic (11% and 12%), stearic (7% and 11%), oleic (10% and 14%), and linoleic acid (71% and 63%) for two samples. 

The development of a characteristic, objectionable, beany, grassy, and hay-like flavor in soybean oil, commonly known as reversion flavor, is a classic problem of the food industry. Soybean oil tends to develop this objectionable flavor when its peroxide value is still as low as a few meq/kg, whereas other vegetable oils, such as cottonseed, com, and sunflower, do not (15, 51). Smouse and Chang (52) identified 71 compounds in the volatiles of a typical reverted-but-not-rancid soybean oil. They reported that 2-pentylfuran formed from the autoxidation of linoleic acid, which is the major fatty acid of soybean oil, and contributes significantly to the beany and grassy flavor of soybean oil. Other compounds identified in the reverted soybean oil also have fatty acids as their precursors. For example, the green bean flavor is caused by c/i-3-hexenal, which is formed by the autoxidation of linolenic acid that usually constitutes 2-11% in soybean oil. Linoleic acid oxidized to l-octen-3-ol, which is characterized by its mushroom-like flavor (53). 

Sunflower Fatty Acids Regular sunflower oil is characterized by a high concentration of linoleic acid, followed by oleic acid. Saturated fatty acids (mainly palmitic acid and stearic acid) do not amount to more than 15% of the fatty acid content. Table 1 shows the variation range of major fatty acids in regular sunflower oil (9, 20). 

Table 7 shows the fatty acid composition of different citrus seed oils. The ratio of unsaturated to saturated fatty acids is approximately 2 1 (9), although this ratio was reported to be in the range of 3-5 1 by Nagy (35). Generally, different varieties, cultivar, location, storage condition, and harvesting time of citrus fruit may lead to this variation. Table 8 shows the content of the six major fatty acids in different citrus seed oils these are linoleic (C18 2), palmitic (C16 0), oleic (C18 l), linolenic (C18 3), stearic (C18 0), and palmitoleic (C16 l) acids. 

Linoleic acid (Cl8 2) was the predominant component of barley neutral lipids (Table 28). Oleic (18 1) and palmitic acid (16 0) were the other major fatty acids in all the barley fractions. A significant amount of polyunsaturated acid, hnolenic (18 3), was also detected in all the barley fractions. Arachidic acid (C20 0) was present in measurable amounts in hull fraction of barley. 

The fatty acid composition of oat lipids is similar to that of the barley oil (Table 28). Linoleic acid is the major fatty acid in all the grain fractions. Oat lipids are also rich in oleic acid. Palmitic acid is the third major fatty acid in oat oil. 

Colocynthis citrullus seed oil and found that it contained a relatively high percentage of linoleic acid that accounted for 57.7% of total fatty acids (Table 4) (26). Oleic acid was the second major fatty acid (14.5%). The seed oil contained about 25.3% saturated fatty acids (Table 4). Moussata and Akoh (27) also reported a similar fatty acid profile of Colocynthis citrullus L. seed oil. The primary fatty acid was linoleic acid, contributing 65.4% of total fats. The other significant fatty acids included oleic (13.5%), palmitic (12.1%), and stearic (9.0%) acids (Table 4). 

Paprika Capsicum annuum) is a commonly used flavor enhancer, and following production, the seeds are treated as waste. Paprika seed oils have been evaluated for their physicochemical properties (22, 23, 32). Paprika seed oil contained more than 82% of total unsaturated fatty acids, with polyunsaturated fatty acids comprising 67.8% of total fatty acids (Table 4) (22, 23). Oleic acid was the second major fatty acid at approximately 15% of the total. This fatty acid profile was consistent with a previous observation by Domokos et al. (32) on the fatty acid profile of Hungarian paprika seed oils. Linoleic acid comprised 74.4% of the total fat, whereas oleic and palmitic acid made up 9.8% and 11.2% of total fat, respectively (32). The paprika seed oil was determined to contain 870 mg/kg oil total tocopherols, 380 mg/kg oil carotenoids, and 0.92% phytosterols (32). 

The cherry tree Prunus avium L.) is a member of the Rosaceae family. Cherry seed contains about 18% oil on a dry weight basis (48). Significant levels of oleic acid were detected in the cherry seed oils prepared by hexane extraction using a Soxhlet apparatus. Oleic acid comprised 24—38% of the total fatty acids from three different varieties of cherry fruits (Table 7) (48). Linoleic acid was the major fatty acid in the cherry seed oil, and ranged 40 9% in the seed oil, along with ot-eleostearic (18 n-5), palmitic, stearic, arachidonic, and ot-linolenic acids (Table 7). alpha-eleostearic acid comprising 10-13% of cherry seed oil, is a conjugated... 

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. 

Changing from the n-3 fatty acid-deficient diet (safflower oil) to the n-3-rich diet (fish oil) increased the total plasma n-3 fatty acids greatly, from 0.1% to 33.6% of total fatty acids (Fig. 1). EPA, which was especially high in the fish oil, contributed the major increase, from 0% to 22.1%, and represented 66% of the total n-3 fatty acid increase. DHA increased from 0.1% to 8.3% and 22 5n-3 from 0% to 2.1%. A major reciprocal decrease occurred in the n-6 fatty acid linoleic acid, which was reduced from 54.3% to 9.2% of total fatty acids and total n-6 fatty acids fell from 65.4% to 15.5%. The change in arachidonic acid, however, was relatively small, from 6.4% to 5.5%. These changes were certainly manifest as early as 2 wk after repletion and were completed by 6-8 wk. The restored fatty acid values then remained constant until autopsy. 

A supercritical fluid extraction (SFE) method for analysis of CO2 extractables in cranberry seeds was investigated. The SFE operating conditions were optimized to maximize the extraction yields. Extraction yields obtained by SFE were comparable to conventional Soxhlet extraction. The extracts were derivatized and then analyzed by GC-MS. The extracts obtained via hexane and CO2 mostly contained methylated fatty acids. Linoleic acid and palmitic acid were the major compounds extracted. 

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