Lipid linolenic acid ratio

Changes in the relative levels of PUFA of the n-6 and n-3 series in tissue lipids of animals fed diets with different n-6/n-3 fatty acid ratios, are thus greater than those found in animals fed a fat free diet in comparison with the controls. This could be of practical significance, since linoleic/linolenic acid ratios are quite different in edible fats of common use. 

The amount of TBA reactant can be converted into moles of malondialdehyde by the extinction coefficient of 155 mM cm ozone (22), and the yield of this reaction, or ratio of malondialdehyde/ozone taken-up, is shown in Figure 9. Notice that the yield for ozone-treated linolenic acid varies with time of reaction from about 3% to over 30%. These results differ from those for lipid peroxidation reactions which also give rise to malondialdehyde but have yields of 2-5% (23). 

Chan, J.K., McDonald, B.E., Gerrad, J.M., Bruce, V.M., Weaver, B.J., and Holub, B.J. 1993. Effect of dietary alpha-linolenic acid and its ratio to linoleic acid on platelet and plasma fatty acids and thrombogenesis. Lipids 28, 811-817. 

Several studies have confirmed that the seed oil from the North American variety of cranberry contains significant levels of a-linolenic acid. In a U.S. patent, Heeg et al. (4) reported the a-linolenic acid content of cranberry seed oil to be between 30% and 35% of total fatty acids. In 2003, Parker et al. (5) found 22.3% a-linolenic acid in the cold-pressed cranberry seed oil, and in 2004, Parry et al. (3) determined the oil to contain 32.0% a-linolenic acid from two different lots of the seed oil. The ratios of n-6 to n-3 fatty acids in all were low from 1.2 1 to 2 1. Also, all of the studies documented similar ratios among the rest of the common fatty acids found in cranberry seed oil, including, in order of higher amount present linoleic, oleic, palmitic, stearic, and eicosadienoic (20 2) acids (Table 1). In addition to a-linolenic acid, cranberry seed oil is rich in natural antioxidants (8). These antioxidants may directly react with free radicals and prevent lipid oxidation in human low-density lipoprotein. 

Ratio of linoleic to linolenic acid in polar lipids of cotton seedlings (15). ... 

The fatty acid composition of blood lipids depends on the diet. Normally, much arachidonic acid and only small quantities of dihomo-y -linolenic acid are present (ratio about 10 1). In the case of a fish oil diet, the amount of eicosapentaenoic acid can be increased considerably. 

Temperature and light have a large influence on linolenic acid levels. Low temperatures have been correlated with an increased ratio of polyunsaturated to saturated lipids in plant cell membranes, while plant tissues maintained in the dark show a significant increase in the desaturation of linoleate to linolenate upon illumination... 

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