Polyunsaturated fatty acids health importance

These reactions are of the utmost importance in ensuring the formation of the polyunsaturated fatty acids that are essential for health (see below). 

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. 

Lipid oxidation is an important topic in food science and technology since the reaction of polyunsaturated fatty acids with oxygen leads to rancidity and quality loss. The same process is important in human health, since the polyunsaturated fatty acids from lipids present in blood plasma (low density lipoproteins, LDL) are oxidised by oxygen in a free radical mediated reaction, promoting the development of atherosclerosis. LDL enters the arterial wall from the plasma and is oxidised locally within the wall by oxidising agents derived from the cells present in atherosclerotic... 

The right balance of n-6 and n-3 polyunsaturated fatty acids (PUFA) is important for good health. The n-3 PUFA such as eicosapentaenoic acid PA) and docosahexaenoic acid (DHA) are mainly found in fish oils. Marine plants can convert a-linolenic acid (ALA) into EPA and DHA, which find their way through the food chain to fish tissues. Another source of n-3 PUFA is the ALA that is found mainly in flaxseed, canola, and soybean oils. Unlike plants, mammals cannot convert oleic acid into linoleic acid, linoleic acid into ALA, or convert n-6 PUFA to n-3 PUFA. Linoleic acid and n-3 PUFA are therefore known as essential fatty acids (1). 

The studies published in this promising area of flavor chemistry and physiology have been limited to a few volatile compounds. They need to be extended to the multitude of other volatile compounds derived from lipid oxidation. Many of these volatiles are known to have a significant impact on quality and acceptability of lipid-containing foods. The complex volatiles produced by food lipids containing n-3 polyunsaturated fatty acids reported to impart nutritional and health benefits are especially important because they develop undesirable fishy odors and flavors at extremely low levels of oxidation (Chapter 4.D Chapter 5.F Chapter ll.E). 

Fish with high fat contents is an important source of long-chain n-3 polyunsaturated fatty acids (PUFAs) in the human diet, in particular for docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) (EFSA, 2005). On the other side, a wide range of environmental contaminants have been reported to be accumulated in fish that can pose a potential human health hazard (Leonard, 2011). Major contaminations include the different OCPs, PAHs or the widely distributed persistent organic pollutants (POPs) with the polychlorinated biphenyls (PCBs) and the flame retardants compound class of the polybrominated diphenylethers (PBDEs). Also farmed fish can significantly contribute to dietary exposure to various contaminants due to the use of land sourced fish feed. A multi method for efficient control of fish and fish feed for various groups of contaminants from PCBs, OCPs, BFRs (brominated flame retardants) and PAHs is outlined in the following analytical procedure published by Kamila Kalachova et al. (Kalachova et al., 2013). 

Monounsaturated and polyunsaturated fatty acids are extraordinarily important in human health and nutrition. Thus, the insertion of double bonds into the carbon skeleton of a fatty acid is a vital metabolic function. However, humans are in general not capable of inserting double bonds closer than nine carbon atoms from the methyl end of a fatty acid. Thus, we are incapable of the de novo synthesis of... 

The fatty acids are a family of long-chain carboxylic acids that may be saturated, monounsaturated, or polyunsaturated. Several fatty acids are essential components of the human diet. Dietary intake of fats has important implications for health and well-being. 

The composition of avocado, in tenns of macronutrients, has been widely studied and is compiled in different tables of food composition. According to the United States Department of Agriculture (USDA) National Nutrient Database for Standard Reference [83], 100 g of avocado are an important source of energy (160 kcal) and contain 73.23 g of water, 2 g of proteins, 14.66 g of total fat (67% monounsaturated, 12% polyunsaturated, and 14% saturated fatty acids), and 8.53 g of carbohydrates, of which 6.70 g are total dietary fiber and 0.66 g are sugars. As it can be seen, one of the main components of avocado is the fat, and thus it is not surprising that it is also known as butter fruit. Besides, some of the principal health benefits of avocado have been attributed to its high monounsaturated fatty acid content. These facts make lipids one of the most studied families of compounds in avocado. 

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