Mono-unsaturated fatly acid

Subsequent epidemiological studies have supported the association between better health and long-term consumption of diets rich in foods of plant origin. " However, whether this is because such diets minimize exposure to deleterious substances (e.g., oxidized cholesterol, pyrolysis mutagens, salt, saturated fat, etc.), or maximize intake of certain beneficial nutrients (e.g., isothiocyanates and other sulfur-containing plant constituents, mono-unsaturated fatty acids, and poly-unsaturated fatty acids, PPT, poly acetylenes, selenium, terpenes, etc.) or some combination as advocated in the Polymeal concept, remains unknown. " An in vitro study indicates that there may be mechanistic basis for true synergy between PPT and isothiocyanates. ... 

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... 

Oil Saturated fat % Mono-unsaturated fatty acid % (MUFA ) Polyunsaturated fatty acid % (PUFA) Linolenic fatty acid % Linoleic fatty acid %... 

This allows for the percentage composition of individual fatty acids present in the sample to be determined, enabling levels of saturated, polyunsaturated, and mono-unsaturated fats to be calculated. 

In contrast to cis-9, trans-11 and trans-1, cis-9, the other isomers of CLA found in milk and body fat of ruminants appear to originate exclusively from rumen output. These are detected in rumen fluid (61) and duodenal fluid (39), and estimates of duodenal flow indicate that rumen output of these minor cis/trans, cis-cis, and trans-trans CLA isomers is greater than the trace amounts secreted in milk fat (39). The common theme to endogenously synthesized CLA isomers is A -desaturase and the cis-9 double bond that is added to trans-1 and trans- 1 monoenes. In contrast, there has been no demonstration that other mammalian desaturases act in a manner analogous to A -desaturase to synthesize CLA endogenously from mono-unsaturated fatty acids. Thus, these other CLA isomers found in trace levels in ruminant fat are of rumen origin and must represent intermediates in the ruminal biohydrogenation of linoleic and linolenic acids. 

The major contributions of saturated fatty acids originates mainly from vegetable oils such as coconut and palm kernels. The animal fats with the exception of marine oils contain large amounts of saturated fatty acids butterfat (63%), beef tallow (46%) and lard (42%). Marine oils, besides containing mono-unsaturated fatty acids, also contain long chain fatty acids with 20 carbon atoms and 4-6 double bonds. These are discussed in chapter 10. 

The current North American intake of total dietary fat is about 38% of calories with approximately 13-15%, 5-7% and 16-18% of calories supplied by saturated, polyunsaturated and mono-unsaturated fatty acids, respectively (Grundy, 1989). This provides for a current P/S ratio of about 0.45. There is ample evidence that these levels of total fat, and especially saturated fat, are too high and represent significant risk factors for coronary heart disease and possibly cancer at specific sites. Various agencies (American Heart Association, 1988 National Research Council, 1989 American Cancer Association and the US Department of Agriculture, US Department of Health and Human Services, 1990 Health and Welfare Canada, 1990) have recommended that the current total fat consumption be reduced to 30% of calories, with the contribution of saturated fat not to exceed 10% of calories. Furthermore, an increase in the P/S ratio from the present value of 0.45 to a value of 1.0 is also recommended. This provides for an intake of polyunsaturated fat at 10% of calories with the last 10% of fat calories supplied by mono-unsaturated fat. It is emphasized that these recommendations are for adults and children over 2 years of age. 

The nutritional value of nut and seed products is closely associated with the fatty acid content of the oil. High Unoleic acid content decreases shelf-life. Increasing the oleic/linoleic acid ratio produces a more stable oil with a longer shelf-life. Nutritionally, a high linoleic acid content is desirable, because this acid is an essential fatty acid and produces a hypocholenic effect. Of more than 100 fatty acids, three are essential, linoleic, linolenic and arachidonic. The consensus is that polyunsaturated fat (fatty acids) lowers total blood cholesterol and low-density lipoprotein levels. Lx)w levels of these substances are associated with reduced risk of coronary heart disease and atherogenesis. Mono-unsaturated fatty acids may be beneficial in lower blood cholesterol (Sheppard and Rudolf, 1991). 

Polyunsaturated fats are known as essential fats. Like vitamins they are essential for hfe, they cannot be made in the body and must be obtained from the diet. These good fats have actually been shown to counter the effects of bad fats in our blood and are important for maintaining good health of our hearts, cells and nervous systems. In contrast to saturated and mono-unsaturated fatty acids, PUFAs have at least two double bonds, a feature which crucially affects their structural, physical and chemical properties. 

Saturated fatty acids (no double bonds), such as myristic, palmitic, and stearic, make up two-thirds of milk fatty acids. Oleic acid is the most abundant unsaturated fatty acid in milk, with one double bond. Triglycerides account for 98% of milk fat. The small amounts of mono-, diglycerides, and free fatty acids in fresh milk may be... 

Podlaha, O. and Toregard, B. (1984) HPLC separation of mono-unsaturated triglycerides with respect to a- or (5-position of oleic acid in some vegetable fats. Fette Seif. Anstrichm., 86, 243-245. Polidori, P., Chiesa, L., Moretti, V.M. and Valfre, F. (1996) Milk fat quality nutritional and sensorial parameters related to butter production. Ind. Aliment., 35, 8-12. 

Majority of fatty acids exist in the form of glycerol ester and these constitute a major esterified to glycerol fraction of fats of oils. As an example, in palm oil, the natural mixture of fatty acids is separated into two fractions, namely olein, which contains the lowest possible amount of saturated fatty acids, and stearin, which contains the lowest possible amount of unsaturated fatty acids. Independent of the process of separation employed, the starting mixture of fatty acids or feed stock should meet certain specifications. A high-quality product with undamaged fatty acids (e.g., less oxidation, minimum isomerization) and fatty acids in the form of mono-, di-, or triacylglycerols, or salts of fatty acids with minimum amount of impurities is necessary for the feed stock (1). 

Optimum balance of the three principal fatty acids polyunsaturates, mono-unsaturates, and saturates. The patented oil blend enhances the good to bad cholesterol ratio when fat intake is balanced in the diet with total fat limited to 30% of calories and dietary cholesterol to under 300 mg per day. 

CBEs are nonhydrogenated specialty fats containing the same fatty acids and symmetrical mono-unsaturated triacylglycerols as cocoa butter. They are fully compatible with cocoa butter and can be mixed with cocoa butter in any ratio in the chocolate formulations. 

The relevance of the molecular structural diversity of the TAG to practical application may be understood by taking some examples of natural fats cocoa butter with major TAG of POP (l,3-dipalmitoyl-2-oleoyl-jn-glycerol), POS (1,3-palmitoyl-stearoyl,2-oleoyl-rac-glycerol) and SOS (l,3-distearoyl-2-oleoyl-jn-glycerol), milk fats whose major TAG are saturated-unsaturated mixed-acid TAG, and mixed-acid TAG with saturated fatty acids having different chainlengths (2). In these natural fats, few mono-acid TAG are present as major TAG components, and the major fats are composed of the mixed-acid TAG. Therefore, it is required to elucidate for the polymorphic structures of the mixed-acid TAG. 

In mixtures, 2-nonenal and 2,4-heptadienal are more rapidly oxidized than methyl linoleate and linolenate, and these fatty esters are more readily oxidized than nonanal. Therefore, during the more advanced stages of oxidation the saturated aldehydes accumulate and the unsaturated aldehydes are further oxidized to lower aldehydes and dialdehydes. At elevated temperatures, saturated aldehydes and dialdehydes are further oxidized into mono- and dibasic acids. The formation of low molecular weight volatile acids is used as a measure of thermal oxidation of fats, and is the basis for detection in some high temperature stability tests (Chapter 7). 

Thermal oxidation of unsaturated fats is accompanied by considerable isomerization of double bonds, leading to products containing trans double bonds and conjugated double bond systems. Non-volatile decomposition products are formed by thermal oxidation, hydrolysis and cyclization. A large number of hydroxy, alkoxy-substituted, epoxy and keto compounds are produced by oxidation, free fatty acids and mono- and diacylglycerols by hydrolysis, and cyclic monomers by cyclization of polyunsaturated fatty acids in heated fats. Aldehydo glycerides (also referred to as core aldehydes ) and keto glycerides... 

Unsaturated fats, found in plants, are better choices for a healthful diet. These fats, usually soft or liquid at room temperature, vary from mono-unsaturated (the major fatty acid in olive oil) to polyunsaturated fatty acids (found in cottonseed, soybean, corn, and canola oils). Hydrogenation, a process that changes fatty acids from liquid to solid, creates trans fats. Trans fats raise blood cholesterol levels and may contribute to heart disease. 

---