Conjugated linoleic acid/oxidation

Regarding the compositional differences shown for animal products, whether they are important for health depends, as for the plants, on the overall composition of the diet of the people who eat them. The vitamin E content in milk is far too small for relevant differences to affect health (Nielsen ef al. 2004), and too little is known about the dose-response relations of the impact of conjugated linoleic acids on health. However, the increased vitamin E level may still be important to prevent oxidation of the fat, a problem that can be exacerbated by increased levels of polyunsaturated fatty acids (Dhiman ef al. 1999, Nielsen ef al. 2004). However, while oxidised milk is clearly not good for health, its rancid taste and smell allows detection and rejection before consumption and thus prevents harm to health, similar to plant toxicants. Also in line with the plants, while the use of roughage is clearly more extensive in organic farming, some conventional farmers use almost identical feed compositions and are therefore likely to produce the same quality of products in this respect. 

Takahashi, Y., Kushiro, M., Shinohara, K., and Ide,T. 2003. Activity and mRNA levels of enzymes involved in hepatic fatty acid synthesis and oxidation in mice fed conjugated linoleic acid. Biochim. Biophys. Acta, 1631, 265-273. 

The first, important step in the bioconversion of linoleic acid into conjugated linoleic acid (CLA) is the preparation of an adequate amount of bacterial biomass with suitable physiological properties, such as the high activity of key enzymes reliable for the biotransformation. The second step is bioconversion of linoleic acid to CLA. LA conversion to CLA occurs in anaerobic conditions because the presence of oxygen promotes oxidative metabolism in some bacteria and results in lower CLA production (Ogawa et al, 2001). Many bacterial strains of Lactobacillus, Lactococcus, Streptococcus, Bifidobacteria, Propioni-bacterium, Butyrivibrio and bacterial isolated from various sources have been... 

Jimenez, M., Garcia, H.S., and Beristain, C.I. (2004). Spray-drying microencapsulation and oxidative stability of conjugated linoleic acid. Eur. Food Res. Technol. 219, 588 592. 

In polyunsaturated fatty acids with nonconjugated double bonds, O2 reacts with each C=C as if it were isolated, so it yields roughly equivalent amounts of hydroperoxides at both internal and external positions. However, if the double bonds are conjugated (e.g., natural conjugated linoleic acid or oxidized linoleic acid), cyclic endoperoxides are formed. 

Riserus, U., Basu, S., Jovinge, S., Fredrikson, G.N., Aralov, J., and Vessby, B. 2002. Supplementation with conjugated linoleic acid causes isomer-dependent oxidative stress and elevated C-reactive protein A potential link to fatty acid-induced insulin resistance. Circulation 106, 1925-1929. Rossetti, R.G., Seiler, C.M., DeLuca, P., Laposata, M., and Zurier, R.B. 1997. Oral administration of unsaturated fatty acids Effects on human peripheral blood T lymphocyte proliferation. J. Leukoc. Biol 62, 438-443. 

Dienoyl-CoAs might be generated fortuitously by A, A -enoyl-CoA isomerase acting on 2,5-dienoyl-CoAs that are normal P-oxidation intermediates of unsaturated fatty acids with odd-numbered double bonds. However, 3,5-dodecadienoyl-CoA is an obligatory metabolite of 9-cis,ll-trans-octadecadienoic acid, also referred to as conjugated linoleic acid, which is a minor fatty acid of the human diet. 

Rahman, SM., Wang, Y.M., Yotsumoto, H., Cha, J.Y, Inoue, S., and Yanagita, T. (2001) Effects of Conjugated Linoleic Acid on Serum Leptin Concentration, Body Fat Accumulation and Beta-Oxidation of Fatty Acid in OLETF Rats, Nutrition 17,385-390. 

Conjugated Linoleic Acid Amylase Inclusion complex via hydrophobic interactions Protection against oxidation and dispersion in aqueous phase [126]... 

Chae, S. H., Keeton, J. T., Smith, S. B. (2004). Conjugated linoleic acid reduces lipid oxidation in aerobicaUy stored, cooked ground beef patties. Journal of Food Science, 69, 306-309. 

Joo, S. T., Lee, J. L, Ha, Y. L., Park, G. B. (2002). Effects of dietary conjugated linoleic acid on fatty acid composition, lipid oxidation, color, and water-holding capacity of pork loin. Journal of Animal Science, 80, 108-112. 

Detection of Partial P-Oxidation Products of Conjugated Linoleic Acid Isomers and Their Metabolites in Animals and Humans... 

Banni, S., A. Petroni, M. Blasevich, G. Carta, E. Angioni, E. Murra, B.W. Day, M.P. Melis, S. Spara and C. Ip. Detection of Conjugated C16 PUFAs in Rat Tissues as Possible Partial Beta-Oxidation Products of Naturally Occurring Conjugated Linoleic Acid and its Metabolites. Biochim. Biophys. Acta 1682 120— 27 (2004). 

Effects of Conjugated Linoleic Acid on Serum Leptin Concentration, Body-Fat Accumulation, and Beta-Oxidation of Fatty Acid in OLETF Rats, Nutrition 17 385—390 (2001). 

Involved in Hepatic Fatty Acid Synthesis and Oxidation in Mice Fed Conjugated Linoleic Acid. Biochim. Biophys. Acta-Molecular Cell Biol Lipids 1631- 265—273 (2003). 

Devery, R., A. Miller, and C. Stanton. Conjugated Linoleic Acid and Oxidative Behaviour... 

We have long been interested in development of new ESR techniques and utilization of ESR techniques to study anti- and/or pro-oxidant activities in a variety of foods products, dietary supplements, functional foods, herbals, and phytochemicals. Our studies have included wheat, herbal products, dietary supplements, conjugated linoleic acid, strawberry, flavonoids, Aloe vera, vitamin A, and food contaminants, including fumonisin Bl and polycyclic aromatic hydrocarbons. In this paper, we... 

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