Polyunsaturated fatty acids distribution

Fig. 3. Polyunsaturated fatty acid distribution in a G. maxx G. soja 2 population. The Glycine max parent of this interspecific cross, N85-2122, carries the fap allele for low-palmitic acid. The Glycine soja parent, PI 366121, exhibits high polyunsaturated fatty acid composition. Experimental approach is outlined in Pantalone etal. (9).

Figure 9.17 Distribution of major fatty acids ( xg fatty acids L-1 and xg fatty acid mg-1 OC) in particulate organic matter (POM), very high molecular mass dissolved organic matter (VHDOM) (30 kDa-0.02 xm), and high molecular mass DOM (HDOM) (1-30 xm) in Delaware Bay estuary. Bacterial fatty acids (FA) included branched and normal saturated acids and 15 1A4 and PUFA = polyunsaturated fatty acids. (Modified from Mannino and Harvey, 1999.)...

The positional distribution of fatty acids in phosphatidylcholine and phosphatidylethanolamine, the major glycerophospholipids, of bovine milk, were investigated by Morrison et al. (1965) and are shown in Table 1.13. Unlike triacylglycerols, phospholipids do not contain short-chain fatty acids (14 0 being the shortest chain fatty acid present at a significant level). This is probably due to differences in the route of synthesis, as most short-chain fatty acids are found at the sn-3 position of triacylglycerols, which in phospholipids is occupied by the phosphate moiety. In phospholipids, the polyunsaturated fatty acids tend to be esterified preferentially at the sn-2 position, while the saturated fatty acids show a preference for the sn-1 position (Table 1.13). For phosphatidylethanolamine, 18 2 and 18 3 are found predominantly at the sn-2 position, while 18 1 is fairly evenly distributed and 16 0 and 18 0 are predominantly at the sn-1 position. In phosphatidylcholine, which is more saturated than phosphatidylethanolamine, the distribution of saturated and unsaturated fatty acids is less distinct between... 

The positional distribution of the fatty acids in two phospholipids, phosphatidylcholine and phosphatidylethanolamine, in bovine and human milk is described in Table 1.13 (Christie, 1995). The fatty acids in bovine milk phospholipids have a lower degree of unsaturation than those in human milk phospholipids. However, the distribution of fatty acids between the two positions is similar. Polyunsaturated fatty acids are attached preferentially at the sn-2 position, the monounsaturates are distributed similarly between the two positions, and 18 0 is esterified preferentially at the sn-1 position while the other saturated fatty acids (14 0, 16 0) are distributed more evenly (bovine phosphatidylethanolamine being an exception). The phospholipids in human milk show remarkable selectivity for 18 0 at the sn-1 and 18 2 at the sn-2 positions. 

Enrichment of the dietary fat with PLs or TAGs may or may not affect fecal excretion of fat and minerals and may increase or decrease saturated fat absorption depending on the PL and TAG source (83). Long-chain polyunsaturated fatty acids were better absorbed in preterm infants when fed as PLs than as TAGs (84). Feeding long-chain polyunsaturates as PLs or TAGs influences the distribution of these fatty acids in plasma lipoprotein fractions, affects their content in different plasma... 

Countercurrent Chromatography Countercurrent chromatography (CCC) or centrifugal partition chromatography (CPC) has gained much attention in recent years for isolation of polyunsaturated fatty acids. This new liquid chromatographic technique uses liquid-liquid partition, countercurrent distribution of solute mixmre between two liquid phases, in the absence of a solid support, to perform separation of complex mixture of chemical substances (44, 45). 

An asymmetric lipid distribution between the exoplasmic and cytoplasmic leaflets of plasma membranes is typical (Devaux, 1991). Por example, it is well documented that highly unsaturated species of PE and PS are found primarily on the inner leaflet of many membranes. This has been reported for human erythrocytes (Knapp et al., 1994), murine synaptosomal plasma membranes (Pontaine et al., 1980), and human lymphocytes (Bougnoux et al., 1985), among others. It has also been shown that polyunsaturated fatty acids, including DHA, are found in higher concentrations in the aminophospholipids in the inner, cytoplasmic leaflet (Crinier et al., 1990 Hullin et al., 1991). As a result, the cytoplasmic leaflet of erythrocytes is more fluid than the exoplasmic leaflet (Morrot et al., 1986). The addition of polyunsaturated fatty acids to membranes have been shown to translocate cholesterol to the outer leaflet, where its efflux from membranes is enhanced (Dusserre et al., 1995). 

W atanabe I, Aonuma H, Kaneko S, et al. Effect of high linoleate and high (/.-linoleate diets on size distribution of phagosomes in retinal pigment epithelium. In Yasugi T, Nakamura H, Soma M, eds. Advances in Polyunsaturated Fatty Acid Research. Elsevier, Amsterdam, 1993. 

Clarity at or below ambient room temperature is the primary characteristic of a liquid oil. Natural vegetable oils that are liquid at room temperatures in temperate climates, 75 5°F (23.4 3°C), contain high levels of unsaturated fatty acids with low melting points. Fatty acids with one or more double bonds and 18 carbon atoms are the most important unsaturated fatty acids for liquid oils. Oleic (18 1), a monounsaturated fatty acid, is the most widely distributed and most stable Ci8 unsaturated fatty acid. Linoleic (18 2) and linolenic (18 3) are the most widely distributed di- and triunsaturated fatty acids. Both of these polyunsaturated fatty acids are termed essential because they cannot be synthesized by animals, including man, and must be supplied in the diet. Complete exclusion of the essential fatty acids from the diet results in scaly skin, loss of weight, kidney lesions and eventually death. 

Lipoxygenases (LOX) constitute a family of lipid peroxidizing enzymes, which are distributed widely in the plant and animal kingdoms. These enzymes preferentially metabolize substrates that are polyunsaturated fatty acids containing a series of cis double bonds, which are the essential fatty acids for human beings (Kuhn Thiele, 1999). Lipoxygenases are dioxygenases in nature and... 

C2o polyunsaturated fatty acids (PUFAs see Tables 6 and 7 and Fig. 4) exhibit unique biological activities, such as lowering the plasma cholesterol level and preventing thrombosis. As food sources rich in PUFAs are limited to a few seed oils and fish oils, alternative microbial sources of PUFAs are of high interest. The species distribution of PUFAs produced by Mor-... 

Aubourg, S.P., Medina, L, and Perez-Martin, R., 1996, Polyunsaturated fatty acids in tuna phospholipids distribution in the sn-2 location and changes during cooking, J. Agric. Food Chem., 44, 585. 

Amate, L., and Ramirez, M. (2001) Feeding Infant Piglets Formula with Long-Chain Polyunsaturated Fatty Acids as Tria-cylglycerols or Phospholipids Influences the Distribution of These Fatty Acids in Plasma Lipoprotein Fractions, J. Nutr. 757,1250-1255. 

Fig. 4. Gas chromatograms and distribution of radioactivity in % of polyunsaturated fatty acids of rat liver, (a) Fat-free diet with addition of linoleic acid, at the end of the experiment 14-Ct<-A t2-Cjg.2. (b) Fat-free diet with addition of linolenic acid, at the end of the experiment (c) Normal diet...

The human body can synthesize all except two of the fatty acids it needs. These two, linoleic acid and linolenic acid, are polyunsaturated fatty acids that contain 18 carbon atoms (Table 8.1). Because they are not synthesized within the body and must be obtained from the diet, they are called essential fatty acids. Both are widely distributed in plant and fish oils. In the body, both acids are used to produce hormonelike substances that regulate a wide range of functions and characteristics, including blood pressure, blood clotting, blood lipid levels, the immune response, and the inflammation response to injury and infection. 

The triglyceride composition offish oils is complex, and detailed studies are not available. Current work on fatty acid distribution suggests that polyunsaturated acids (20 5 n—3 and 22 6 3) occupy... 

There has been increasing interest in cereal lipids because of their importance in food technology (e.g. in wheat flour) or as potential sources of significant amounts of dietary polyunsaturated fatty acids (Price and Parsons, 1974). Morrison and co-workers have conducted a systematic study of the distribution of... 

The polyunsaturated fatty acids family is widely distributed throughout nature. They have several double bonds in the principal chain. Common dienoic acids are ds-,ds-9,12-octadecadienoic acid (lioleic acid), /ra s-,/ra s-9,12-octadecadienoic acid (line-laidic acid), 5,9-heneicosadienoic acid, 5,9-do-cosadienoic acid, and 5,9-tricosadienoic acid. 

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