Butter polyunsaturated fatty acids

Initially, of course, we heard about the Inuit Eskimos of Greenland and how they almost never developed heart disease even though they ate large amounts of fat in the form of fish and marine animals. At first glance, that appeared paradoxical. Then came the realization that the fat consumed was a kind of polyunsaturated fatty acid termed omega-3.Think about it if the fat in coldwater fish were saturated, those fish would be as stiff and hard as a stick of butter in the refrigerator. 

Around 1960, the USSR interrupted the supply of sunflower oil to Europe, because of the high internal demand, including satellites, thus leaving an unattended sector in the European market, where consumption of tallow and butter were then indicated as causes of coronary disease. The high content of polyunsaturated fatty acids (PUFA) of sunflower oil naturally interested many American and Canadian oil industries, with the consequent increase in sunflower production in the late 1970s (1). 

The discovery of conjugated linoleic acid (CLA) dates back to 1933, when it was found that treatment of polyunsaturated fatty acids with alkali increased the UV absorbency (1-3). It was later found that the treatment produced a one to one mixture of cis-9-, trans-W- (9,11-ct) and trans- Q-, cis-l2 (10,12-tc) CLA. In 1935, it was noted that UV absorbency at 230 nm of milkfats was higher in milk from cows fed polyunsaturated fatty acids than cows fed saturated fats (4). This phenomenon was shown to be a result of conjugation of the double bonds of the polyunsaturated fatty acids (5). The predominant isomer in dairy products (milk, cheese, butter) or meat is 9,11-ct CLA (6). 

Figure 27-19 Modek of long-chain fatty acids. The saturated fatty acids (a) are linear and tend to pack like sticks of wood to form solid masses in blood vessels, thereby constricting them. The trans unsaturated fatty acids have a slight Z-shaped kink in the chain, but are also essentially linear molecules. By contrast, cis unsaturated fatty acids (b) are bent and so do not pack as well as linear structures and do not collect in blood vessels as readily. Many natural vegetable fats and oils contain esters of cis unsaturated fatty acids, or polyunsaturated fatty acids. Health problems associated with saturated fatty acids can be decreased by eating less animal fat, butter, and lard. Problems due to trans fatty acids are reduced by avoiding processed vegetable fats.

These fats represent two extremes. Many animal body fats have a melting pattern more or less comparable to milk fat. Some vegetable fats, like palm oil and coconut oil, behave like cocoa butter (here the word oil is a misnomer since the clear points are about 40 and 30°C, respectively). A third type includes most vegetable oils, like sunflower, soybean, and peanut oil, that contain a high proportion of polyunsaturated fatty acid residues marine oils also are in this category. They generally have clear points in the range —5 to 5°C. 

In addition to modifying the rheological properties of butter, blends of milk fat and vegetable oils can be produced at a reduced cost (depending on the price paid for milk fat) and have an increased content of polyunsaturated fatty acids, which probably has a nutritional advantage. Oils rich in CO-3 fatty acids, which are considered to have desirable nutritional properties, may be included in the blend, although these oils may be susceptible to oxidative rancidity. 

The most common dietary fatty acids are the saturated long-chain fatty acids palmitate (C16) and stearate (C18), the monounsaturated fatty acid oleate (C18 l), and the polyunsaturated essential fatty acid, linoleate (C18 2) (To review fatty acid nomenclature, consult Chapter 5). Animal fat contains principally saturated and monounsaturated long-chain fatty acids, whereas vegetable oils contain linoleate and some longer-chain and polyunsaturated fatty acids. They also contain smaller amounts of branched-chain and odd-chain-length fatty acids. Medium-chain-length fatty acids are present principally in dairy fat (e.g., milk and butter), maternal milk, and vegetable oils. 

The experimental oil was butter in the saturated fatty acid (SFA), high-oleic acid safflower oil in the monounsaturated fatty acid (MUFA), and safflower oil in the polyunsaturated fatty acid (PUFA) diet Cholesterol was not added to the SFA diet... 

Listed as percent of total fatty acid content, based on 13.6 g fatty acids/tablespoon. Cells without numbers did not have data in United States Department of Agriculture Nutrient Database SFA = saturated fatty acid MUFA = monounsaturated fatty acid PUFA = polyunsaturated fatty acid EPA = eicosapentaenoic acid t)PA = docosapentaenoic acid DHA = docosahexaenoic acid ARA= arachadonic acid TFA = /raw -fatty acid Butter contains 16 % water and therefore the percentages are unable to be directly compared with percentages of the other fats/oils [5],... 

Lipids with saturated fatty acids are called saturated fats and are commonly solids at room temperature (such as butter and shortening). Unsaturated fats contain one or more double bonds in their carbon-carbon chains. The cis and trans nomenclature we learned for alkenes applies Trans fats have H atoms on the opposite sides of the C=C double bond, and cis fats have H atoms on the same sides of the C=C double bond. Unsaturated fats (such as olive oil and peanut oil) are usually Hquid at room temperature and are more often found in plants. For example, the major component (approximately 60 to 80%) of olive oil is oleic acid, ds-CH3(CH2)7CH = CH(CH2)7COOH. Oleic acid is an example of a monounsaturated fatty acid, meaning it has only one carbon-carbon double bond in the chain. In contrast, polyunsaturated fatty acids have more than one carbon-carbon double bond in the chain. 

As a result, monounsaturated and polyunsaturated fatty acids and the triglycerides composed of them are liquid at room temperature. Overall, oils have fatty acids with more cis double bonds. Fats have fewer cis double bonds and more saturated fatty acids. For example, butter has a high content of saturated fats and is a solid... 

Wood, R., Kubena, K., O Brien, B., Tseng, S. and Martin, G. (1993) Effect of butter, mono- and polyunsaturated fatty acid-enriched butter, trans fatty acid margarine, and... 

Medical evidence correlates a diet high in saturated fats with hardening of the arteries (atherosclerosis) and possible heart attack. Table 22.2 lists the percentage of saturated fatty acids, monounsaturated fatty acids, and polyunsaturated fatty acids in some common dietary fats and oils. This table compares human depot (storage) fat with butter and margarines, then with several vegetable oils. 

The effects of polyunsaturated fatty acids on the heart muscle are uncertain, since it has been found that the lifetime feeding of corn, cottonseed, or soybean oils produced more heart lesions in rats than beef fat, butter, chicken fat, or lard. 

Catalytic hydrogenation of vegetable oils is widely used to form harder fats and to decrease the content of polyunsaturated fatty acyl groups. The products have a greatly increased resistance to rancidity. However, they also contain fats with trans double bonds as well as isomers with double bonds in unusual positions.251 253 Such compounds may interfere with normal fatty acid metabolism and also appear to affect serum lipoprotein levels adversely. Trans fatty acids are present in some foods. One hundred grams of butter contain 4-8 g, but hydrogenated fats often contain much more. It has been estimated that in the United States trans fatty acids account for 6-8% of total dietary fat.253... 

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