Triglycerides distribution

German, J.B., Simoneau, C., DePeters, E., Tong, P.S., Mattas, J. and Sullivan, J. (1995) Effects of feeding supplemental fat to dairy cattle on milk fat composition and properties. 2. Triglyceride distribution and milk fat functionality. J. Dairy Set, 78, (Suppl. 1), 134. 

Although obvious correlations exist between fatty acid composition and triglyceride distribution, detailed information is lacking that would enable the triglyceride distribution to be predicted from the fatty acid composition. Much more needs to be understood of the strategy used in the bovine mammary gland in assembling a... 

Cholesterol and triglyceride distribution in the body. The light arrows show the route of both triglycerides and cholesterol. The two heavy arrows denote cholesterol export from peripheral plasma membranes into LDL and via IDL (intermediate-density iipoprotein) and VLDL back to the liver. 

Steele, W. and Banks, W. (1994) Triglyceride distribution in hydrogenated milk fat and its effects on separation by thin layer chromatography. Milchwissenschaft, 49 (7), 372-6. 

Schaefer, L. E. Serum cholesterol-triglyceride-distribution in a normal New York City population. Amer. J. Med. 36, 262 (1964). 

The alcoholysis reaction may be carried out either batchwise or continuously by treating the triglyceride with an excess of methanol for 30—60 min in a well-agitated reactor. The reactants are then allowed to settle and the glycerol [56-81-5] is recovered in methanol solution in the lower layer. The sodium methoxide and excess methanol are removed from the methyl ester, which then maybe fed directiy to the hydrogenolysis process. Alternatively, the ester may be distilled to remove unreacted material and other impurities, or fractionated into different cuts. Practionation of either the methyl ester or of the product following hydrogenolysis provides alcohols that have narrow carbon-chain distributions. 

Oils are mixtures of mixed esters with different fatty acids distributed among the ester molecules. Generally, identification of specific esters is not attempted instead the oils are characterized by analysis of the fatty acid composition (8,9). The principal methods have been gas—Hquid and high performance Hquid chromatographic separation of the methyl esters of the fatty acids obtained by transesterification of the oils. Mass spectrometry and nmr are used to identify the individual esters. It has been reported that the free fatty acids obtained by hydrolysis can be separated with equal accuracy by high performance Hquid chromatography (10). A review of the identification and deterrnination of the various mixed triglycerides is available (11). 

Olive oil was the original model lipid for partition studies, and was used by Overton in his pioneering research [518,524], It fell out of favor since the 1960s, over concerns about standardizing olive oil from different sources. At that time, octanol replaced olive oil as the standard for partition coefficient measurements. However, from time to time, literature articles on the use of olive oil appear. For example, Poulin et al. [264] were able to demonstrate that partition coefficients based on olive oil-water better predict the in vivo adipose-tissue distribution of drugs, compared to those from octanol-water. The correlation between in vivo log Kp (adipose tissue-plasma) and log (olive oil-water) was 0.98 (r2), compared to 0.11 (r2) in the case of octanol. Adipose tissue is white fat, composed mostly of triglycerides. The improved predictive performance of olive oil may be due to its triglyceride content. 

Similar problems occur for the nephelometric and turbidimetric methods, where the sizes of the IgG-Lp(a) complexes depend upon that of apo(a) itself (L2, W4). Furthermore, problems due to interferences from elevated plasma triglyceride are commonly encountered in the precipitation techniques (C3). As Lp(a) can be redistributed among the Lp(a) fraction and the triglyceride-rich lipoproteins, especially in patients after a fatty meal (B11), these methods are not appropriate for monitoring Lp(a) levels and distribution in plasma. 

In Figure 15-1, the Ri, R , and R3 are carbon chain lengths ranging from C4—C22 or more, though in these fats, Cn-C 7 predomiriate. Batches of triglycerides from various sources have their own random distribution of fatty acid chain lengths, but from the same fats and oils the distributions are fairly consistent. 

The methanol and catalysts are recovered for reuse. The mixed fatty alcohols are then fractionated to give the R, R2, and R3 cuts of alcohols. Keep in mind there will be three Bs on the triglyceride, but not necessarily the same three on all the triglycerides. For example, when coconut oil is the raw material, the following distribution of straight-chain primary alcohols typically occurs Table 15—1) ... 

The assumption of a characteristic line pattern for lipids is justified by the fact that IMCL, EMCL, and other adipose tissue in subcutaneous fat tissue or in tibial bone marrow are known to consist mainly of a very similar composition of fatty acid triglycerides. The characteristic line pattern A is indirectly determined by recording a reference lipid spectrum (R) out of a lipid compartment with a relatively homogenous magnetic field described by a normal distribution, i.e., a Gaussian function G. That means R can be written as... 

Bakan DA, Weichert JP, Longino MA, Counsel RE (2000) Polyiodinated triglyceride lipid emulsions for use as hepatoselective contrast agents in CT effects of physicochemical properties on bio distribution and imaging profiles. Invest Radiol 35 69... 

Fig. 8.4 Distribution of serum triglyceride levels from cord blood of 282 babies.

Most commercial products are mixtures because of the way they are manufactured. For instance many surfactant hydrophobes come from assorted products such as petroleiun alkylate cuts or triglyceride oils, with a molecular weight distribution that could be narrow or wide. Usually, a purification and separation of single isomeric species would be too costly and, in most cases, pointless. Moreover, the synthesis reactions involved in the surfactant manufacturing might be the intrinsic reason of the production of a mixture, such as in the case of polycondensation of ethylene oxide which results in an often wide spread ethylene oxide munber (EON) distribution. A residual content of some intermediates or by-products might also be a significant cause for mixture effects. 

However, studies in hypercholesterolemic subjects, using soy protein depleted of isoflavones have shown that soy protein independently of isoflavones can favorably affect LDL size, LDL particle distribution was shifted to a less atherogenic pattern,and can decrease triglyceride concentrations, triglyceride fatty acid fractional synthesis rate, and cholesterol... 

Lipoproteins have hydrophobic core regions containing cholesteryl esters and triglycerides surrounded by unesterified cholesterol, phospholipids, and apoproteins. Certain lipoproteins contain very high-molecular-weight proteins that exist in two forms B-48, formed in the intestine and found in chylomicrons and their remnants and B-lOO, synthesized in liver and found in VLDL, VLDL remnants(IDL),LDL (formed from VLDL), and Lp(a) lipoproteins. HDL consist of at least 15 discrete molecular species. All species contain apolipoprotein A-I (apoA-I). Fifty-three other proteins are known to be distributed variously among the HDL species. 

FHBL (OMIM 107730) is a codominant disorder characterized by plasma levels of total cholesterol, LDL-cholesterol, triglycerides, and apoB below the fifth percentile of the distribution in the general population. FHBL is genetically heterogeneous it may be linked to the apoB gene. The best-characterized FHBL cases are those due... 

Figure 8.15 Cartoon showing how proteins, polysaccharides and surfactants (emulsifiers) might be distributed at the triglyceride-water interface. Inter-facial complexation in vivo between adsorbed protein and charged polysaccharide in the gastrointestinal tract could affect digestion of protein and fat by forming structures that inhibit the accessibility and activity of enzymes (proteases and lipases). Reproduced from Dickinson (2008) with permission.

A systematic investigation of the influence of pre- and post-expansion conditions, and solute concentration (general process parameters) upon the crystallinity, particle size, and particle-size distribution, was performed for the model system glyceride-CCh [67-69]. A glyceride with the compositions, 50-55 wt.% of monoglycerides, 35-40 wt.% of diglycerides, 3-8 wt.% of triglycerides, and less than 1 wt.% of free fatty acids, was used. 

Breckenridge, W. C. and Kuksis, A. 1967. Molecular weight distributions of milk fat triglycerides from seven species. J. Lipid Res. 8, 473-478. 

Parodi, P. W. 1982. Positional distribution of fatty acids in the triglyceride classes of milk fat. J. Dairy Res. 49, 73-80. 

The structure of milk triglycerides is considered in Chapter 4. Here we emphasize only that many different triglyceride molecules are present in lipid globules. Whether these triglycerides are randomly distributed throughout the core or are concentrated into discrete zones or... 

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