Depot fats, animal

Table 3. Typical fatty acid compositions of milks, eggs, animal depot fats, animal muscle (meats) and fish oils ...

Fats and oils may be synthesized in enantiomerically pure forms in the laboratory (30) or derived from vegetable sources (mainly from nuts, beans, and seeds), animal depot fats, fish, or marine mammals. Oils obtained from other sources differ markedly in their fatty acid distribution. Table 2 shows compositions for a wide variety of oils. One variation in composition is the chain length of the fatty acid. Butterfat, for example, has a fairly high concentration of short- and medium-chain saturated fatty acids. Oils derived from cuphea are also a rich source of capric acid which is considered to be medium in chain length (32). Palm kernel and coconut oils are known as lauric oils because of their high content of C-12 saturated fatty acid (lauric acid). Rapeseed oil, on the other hand, has a fairly high concentration of long-chain (C-20 and C-22) fatty acids. 

After uptake, lipophilic pollutants tend to move into hydrophobic domains within animals or plants (membranes, lipoproteins, depot fat, etc.), unless they are biotransformed into more polar and water soluble with compounds having low Metabolism of lipophilic compounds proceeds in two stages ... 

The lipid in muscle is composed primarily of triglycerides (depot fats) and of phospholipids (membrane components), and is a constituent which varies enormously not only in amount present, but also in properties such as degree of saturation (species dependent). The ash of lean meat is comprised of various minerals such as phosphorus, potassium, sodium, magnesium, calcium, iron and zinc Carbohydrate was not noted in the proximate composition because while some may be present, it is normally there in low concentration compared to the other constituents. Glycogen is the carbohydrate occurring in greatest concentration in muscle but is normally degraded soon after the animal is sacrificed. 

Table 11.3 Fatty acids found in animal depot fats (adapted from deMan, 1990 41).

CLA Formation in Nonruminant Animals. CLA has been detected in the serum, bile and duodenal juice of humans (7 ). It has been confirmed that both the cis-9, trans-11 and trans-9, trans-11 CLA isomers are present in human depot fats (79). 

Lovem, J.A. (1942). The composition of the depot fats of aquatic animals. Special Reports of the Food Investigation Board, Lond. 51,1-72. 

The bulk of our knowledge regarding thermal oxidation has been derived from studies with model systems of fatty acids and their derivatives, or with individual natural oils (2,3,6,12,13,14,15,16). However, in biological systems as complex as food, lipids usually exist in a complicated environment markedly different from that of the single phase model system. In cell membranes, for example, the lipid molecules are highly ordered, relatively restricted in distance and mobility, and closely associated with different neighboring molecules, e.g., other lipids, protein, cholesterol, water, pro- and antioxidants. What influence does such an environment have on the oxidation of the lipids at elevated temperature Even in less organized systems, e.g., depot fat from animal or plant, the lipids... 

Depot fats of higher land animals consist mainly of palmitic, oleic, and stearic acid and are high in saturated fatty acids. 

The depot fats of higher land animals, especially mammals, have relatively simple fatty acid composition. The fats of birds are somewhat more complex. The fatty acid compositions of the major food fats of this... 

Table 2-4 Component Fatty Acids of Animal Depot Fats...

The use of animal fats by humans may well predate civilization. As the depot fats of animals are readily noticed during the butchering of a slaughtered animal, are easily harvested, and are available in the absence of plant domestication and the adoption of established agriculture, it is probable that animal fats were the hrst lipids employed as industrial and as distinct edible lipids by humans. This is evidenced by the fact that the paints used in prehistoric cave paintings were animal fat-based, as were the fuels in the lamps that illuminated the cave artists at their work. Despite a tremendous diversihcation to include other lipid types over the intervening centuries, animal fats still play a prominent role in our diets, industry, and commerce. 

The major fat depots of animals include subcutaneous fat (located under the skin and overlying superficial muscles) and intermuscular fat (located between muscles). Appreciable amounts of fat also are deposited in the abdominal cavity and other internal sites. The distribution of fat between different sites varies somewhat with animal species, breed, and degree of finish. 

CiaHJ3Oa mol wl 304.46. C 78.89%. H 10.60%, O 10.51%. An essential fatty acid, q.v, and a precursor m the biosynthesis of prostaglandins, thromboxanes, and leukotrienes, q.q. v. Structure Mo wry et al.. J. Biol. Chem. 142, 679 (1942) Arcus, Smedley-Maclean. Biochem- J. 37, 1 (1943). Occurs in liver, brain, glandular organs, and depot fats of animals, in small amounts in human depot fats, and is a constituent of animal phospha tides. Isolation from Liver lipids Brown, J, Biol. Chem. 80, 455 (1928) from beef... 

Lipids occurring in plant and animal materials consist of structural lipids, which build the cell membranes, and depot fats. The cell and organelle membranes of animal organisms are made of phospholipids and non-esterified cholesterol, whereas in plants they consist of phospholipids and glycolipids. The latter are also found in the central nervous systems of some animals. If a muscle tissue like that in lean fish contains only 0.3% w/w of lipids, they consist almost entirely (90%) of phospholipids. Galactoglycerols and phospholipids serve as important factors in nutrient and antioxidant delivery systems (Herslof, 2000). 

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