Fatty acids saturated short-chain

Octanoic and decanoic acids (saturated short-chain fatty acids)... 

OCTANOIC AND DECANOIC ACIDS (SATURATED SHORT-CHAIN FATTY ACIDS)... 

It is important to underline that both when pyrolysis/methylation and pyrolysis/silyla-tion are used, short chain fatty acids (saturated and unsaturated) are generated from the pyrolitic fragmentation of the cured network formed upon ageing and the fatty acids themselves both saturated and unsaturated forms are observed. 

In contrast to the other large cats, the urine of the cheetah, A. jubatus, is practically odorless to the human nose. An analysis of the organic material from cheetah urine showed that diglycerides, triglycerides, and free sterols are possibly present in the urine and that it contains some of the C2-C8 fatty acids [95], while aldehydes and ketones that are prominent in tiger and leopard urine [96] are absent from cheetah urine. A recent study [97] of the chemical composition of the urine of cheetah in their natural habitat and in captivity has shown that volatile hydrocarbons, aldehydes, saturated and unsaturated cyclic and acyclic ketones, carboxylic acids and short-chain ethers are compound classes represented in minute quantities by more than one member in the urine of this animal. Traces of 2-acetylfuran, acetaldehyde diethyl acetal, ethyl acetate, dimethyl sulfone, formanilide, and larger quantities of urea and elemental sulfur were also present in the urine of this animal. Sulfur was found in all the urine samples collected from male cheetah in captivity in South Africa and from wild cheetah in Namibia. Only one organosulfur compound, dimethyl disulfide, is present in the urine at such a low concentration that it is not detectable by humans [97]. 

Fatty acids consist of a hydrocarbon chain with a carboxylic acid at one end. They can be classified on the basis of the length of the hydrocarbon chain (Table 2.2) and whether there are any double bonds. Trivial names of fatty acids such as butyric, lauric, oleic and palmitic acids are in common use in the food industry. A form of short-hand is used to refer to triglycerides where POS is palmitic, oleic, stearic. If the chain length is the same an unsaturated fat will always have a lower melting point. Another classification of fats that is used is in terms of the degree of unsaturation of the fatty acids. Saturated fats are fats without any double bonds. Many animal fats are saturated, but some vegetable fats, e.g. coconut oil, are saturated also. Mono-unsaturated fats include oils like olive oil but also some partially hydrogenated fats. Polyunsaturated fats have many double bonds and include sunflower oil. Because they are... 

Fatty acids are hydrocarbon chains of various lengths and degrees of unsaturahon that terminate with a carboxylic acid group. The fatty acid chains in membranes usually contain between 14 and 24 carbon atoms they may be saturated or unsaturated. Short chain length and unsaturahon enhance the fluidity of fatty acids and their derivatives by lowering the melting temperature. 

Esterification of glycerol with saturated short chain fatty acids and unsaturated short-and medium chain fatty acids usuaUy results in (at room temperature) liquid oils longer fatty acids give hard fats. Table 23.9 shows several examples of natural and synthetic oils and fats. 

The combinations having predominance of short-chain saturated fatty acids or long chain fatty acids with a considerable degree of unsaturation are liquids at ordinary temperatures and are called oils while others, that are solids at ordinary temperatures, are known as fats. 

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. 

The usual diet of ruminants consists of fresh and preserved herbage and cereals. As a result of microbial activity in the rumen, esterified dietary fatty acids are hydrolyzed, short chain fatty acids are produced by fermentation of cellulose and other polysaccharides, unsaturated fatty acids are hydrogenated and/or converted to geometric (trans) and positional isomers, and microbial lipids are synthesized. These activities account in part for the enormous diversity of fatty acids in milk and the unique features short-chain and a high proportion of long chain saturated fatty acids. (Patton and Jensen, 1976 Christie, 1979B). 

Use a saturated NaCl solution instead of water if working with samples containing a significant amount of short-chain fatty acids, such as milk fat and coconut oil (Bannon et al 1982). 

Butterfat is a mixture of more than 100,000 different triacylglycerols (TAGs) with a melting range from -40 to +40°C (109). About 400 different fatty acids (FAs) are present in butterfat, 25% of which were short-chained and 45% were long-chained saturates (110). Such variety in composition is responsible for butterfat s unique physical properties. 

In the Nurses Health Study (Hu et ah, 1997), the dietary intake of short- and medium-chained saturated fatty acids (4 0-10 0) was not significantly associated with CHD (but other saturated fatty acids were). In an intervention study a higher intake of medium-chained triglycerides was found to significantly decrease total adipose tissue, subcutaneous adipose tissue, and upper-body adipose tissue stores in men compared to longer chained triglyceride consumption (St-Onge, 2005). 

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