Fish fats fatty acid source

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. 

Fa.ts nd Oils. Eats and oils from rendering animal and fish offal and vegetable oilseeds provide nutritional by-products used as a source of energy, unsaturated fatty acids, and palatabiHty enhancement. Eats influence the texture in finished pet foods. The use and price of the various melting point fats is deterrnined by the type and appearance of the desired finished food appearance. 

As mentioned earlier, both MCTs and LCTs are used in tube feeding products. Corn, soy, and safflower oils have been the mainstay sources of fat in these products, providing mainly co-6 polyunsaturated fatty acids (PUFAs). On the other hand, some newer EN products contain higher quantities of co-3 PUFAs from sources such as fish oil [i.e., docosahexenoic acid (DHA) and eicosapentenoic acid or (EPA)]. Still other formulas contain higher quantities of monounsaturated fatty acids from canola oil and high-oleic safflower or sunflower oils. The essential fatty acid (EFA) content (mainly linoleic acid) of EN... 

The effect of dietary fats on hypertriglyceridemia is dependent on the disposition of double bonds in the fatty acids. Omega-3 fatty acids found in fish oils, but not those from plant sources, activate peroxisome proliferator-activated receptor-alpha (PPAR- ) and can induce profound reduction of triglycerides in some patients. They also have antiinflammatory and antiarrhythmic activities. In contrast, the omega-6 fatty acids present in vegetable oils may cause triglycerides to increase. 

If that does occur, then the present system of classification of oils may be impossible to police, and a modified system may become necessary. Perhaps the sale and perceived value of oils will necessarily become dependent on the performance, not the source of the oil. With bulk oils such as palm, peanut, sunflower, safflower, sesame, soya, rapeseed, com, fish, and animal fats and oils, the fatty acid composition will obviously be important for health reasons. If the oil is to be used for frying then the frying properties will be important. In the case of palm products the physical properties and minor components such as carotenoids will be defined. Similarly animal fats will be judged mainly on physical behaviour and effect on the product in which they are used. In all cases the oxidative and stability of the oil will have to be defined. Sesame is a very stable oil, and thus its stability, together with its low level of linolenic acid, would be its major attribute, except for toasted sesame, which would probably be classed as a specialist oil. Already most baking fats sold to the public are blends developed to give the best performance, with no mention on the pack as to the source. If a bulk oil of this type had the desired chemical composition, stability and cooking behaviour, then perhaps the source would not be a matter of concern. 

If formula diets are not used, then the type of protein used is important due to considerations of biological value and digestibility. Milk, animal proteins, egg, certain legumes, and soy products are appropriate, rich sources. If lactose intolerance is encountered, then milk should be replaced with soy-based feeds or an alternative. Fish and vegetable oils are good sources of fats as they provide generous amounts of essential fatty acids and long-chain unsaturated fatty acids. 

The metabolism of n-3 and n-6 PUFAs is interlinked, as they compete for enzymes and metabolic substrates at all levels. Therefore, relative as well as absolute dietary intake is relevant in the determination of tissue n-3 and n-6 fatty acid levels. The Western diet typically contains high levels of n-6 fatty acids, as these are components of most animal and vegetable fats. Dietary sources of n-3 PUFA are varied. The most plentiful sources are fish, shellfish, and marine products, which contain large amounts of EPA and DHA. Certain plant oils, such as rapeseed (canola), soybean, and perilla contain large amounts of LNA (Crawford Sinclair, 1972 Sinclair, 1975). Although beef and lamb do contain n-3 PUFAs, both the absolute content and the n-3 n-6 ratio of PUFAs within these meats is low. 

Coronary Heart Disease Several studies have linked mercury exposure to cardiovascular disease. These studies are important because consumers are advised to eat fish to protect against heart disease. Some fish species contain beneficial omega-3 fatty acids, and fish is also a low-fat source of protein. However, recent studies have raised the possibility that a moderate mercury content in fish may diminish the cardioprotective effect of fish intake in humans. Salonen et al. (2000) reported an association between moderate hair mercury content and accelerated progression of carotid arteriosclerosis in a prospective study among 1014 men aged 42-60 years in Finland. Hair mercury levels > 2 pg g showed a doubling of the risk of... 

Try to get most of your fat from healthy fat sources (olive oil, avocados) and essential fatty acids, such as fish oil, safflower oil, flax seed, borage or evening primrose oil, and nuts. 

Fish oils contain a wide range of fatty acids from C14 to C26 in chain length with 0-6 double bonds. The major acids include saturated (14 0, 16 0, and 18 0), monounsaturated (16 1, 18 1, 20 1, and 22 1) and n-3 polyene members (18 4,20 5,22 5, and 22 6). Fish oils are easily oxidized and are commonly used in fat spreads only after partial hydrogenation. However, they are the most readily available sources of n-3 polyene acids, especially, EPA and DHA, and with appropriate refining procedures and antioxidant addition these acids can be conserved and made available for use in food. The long-chain polyene acids are valuable dietary materials and there is a growing demand for high quality oil rich in EPA and DHA. °... 

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