Trans fat - Wikipedia. Margarine, a common product that can contain trans fatty acids.
Trans fats, or trans- unsaturated fatty acids, trans fatty acids, are a type of unsaturated fat that occur in small amounts in nature, but became widely produced industrially from vegetable fats for use in margarine, snack food, packaged baked goods and frying fast food starting in the 1. In nature, unsaturated fatty acids generally have cis as opposed to trans configurations. Partial hydrogenation of the unsaturated fat converts some of the cis double bonds into trans double bonds by an isomerization reaction with the catalyst used for the hydrogenation, which yields a trans fat. Vaccenyl and conjugated linoleyl (CLA) containing trans fats occur naturally in trace amounts in meat and dairy products from ruminants. Most artificial trans fats are chemically different from natural trans fats. Two Canadian studies.
Trans fats levels can be reduced or eliminated using saturated fats such as lard, palm oil or fully hydrogenated fats, or by using interesterified fat. Other alternative formulations can also allow unsaturated fats to be used to replace saturated or partially hydrogenated fats. Hydrogenated oil is not a synonym for trans fat: complete hydrogenation removes all unsaturated fats. History. At the same time, the invention was extended to a large- scale plant in Warrington, England, at Joseph Crosfield & Sons, Limited.
It took only two years until the hardened fat could be successfully produced in the plant in Warrington, commencing production in the autumn of 1. The initial year's production totalled nearly 3,0. Further success came from the marketing technique of giving away free cookbooks in which every recipe called for Crisco. Normann's hydrogenation process made it possible to stabilize affordable whale oil or fish oil for human consumption, a practice kept secret to avoid consumer distaste. During Napoleon's reign in France in the early 1. United States. In the early 2. United States as a source of protein; soybean oil was a by- product.
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What to do with that oil became an issue. At the same time, there was not enough butterfat available for consumers. The method of hydrogenating fat and turning a liquid fat into a solid one had been discovered, and now the ingredients (soybeans) and the .
Later, the means for storage, the refrigerator, was a factor in trans fat development. The fat industry found that hydrogenated fats provided some special features to margarines, which allowed margarine, unlike butter, to be taken out of the refrigerator and immediately spread on bread. By some minor changes to the chemical composition of hydrogenated fat, such hydrogenated fat was found to provide superior baking properties compared to lard. Margarine made from hydrogenated soybean oil began to replace butterfat. Hydrogenated fat such as Crisco and Spry, sold in England, began to replace butter and lard in the baking of bread, pies, cookies, and cakes in 1.
At first, the argument was a financial one due to lower costs; advocates also said that the unsaturated trans fats of margarine were healthier than the saturated fats of butter. Activists, such as Phil Sokolof, who took out full page ads in major newspapers, attacked the use of beef tallow in Mc. Donald's french fries and urged fast- food companies to switch to vegetable oils.
The result was an almost overnight switch by most fast- food outlets to switch to trans fats. Studies in the early 1.
In 1. 99. 4, it was estimated that trans fats caused 2. United States from heart disease. In trans configuration, the carbon chain extends from opposite sides of the double bond, whereas, in cis configuration, the carbon chain extends from the same side of the double bond.
The trans molecule is a straighter molecule. The cis molecule is bent. If the molecule contains no double bonds, it is said to be saturated; otherwise, it is unsaturated to some degree. Saturated fatty acids are never called trans fats because they have no double bonds. Therefore, all their bonds are freely rotatable. Other types of fatty acids, such as crepenynic acid, which contains a triple bond, are rare and of no nutritional significance. In saturated fatty acids, each carbon atom (besides the last) is connected to its two neighbour carbon atoms as well as two hydrogen atoms.
In unsaturated fatty acids, the carbon atoms that are missing a hydrogen atom are joined by double bonds rather than single bonds so that each carbon atom participates in four bonds. Hydrogenation of an unsaturated fatty acid refers to the addition of hydrogen atoms to the acid, causing double bonds to become single ones, as carbon atoms acquire new hydrogen partners (to maintain four bonds per carbon atom). Full hydrogenation results in a molecule containing the maximum amount of hydrogen (in other words, the conversion of an unsaturated fatty acid into a saturated one). Partial hydrogenation results in the addition of hydrogen atoms at some of the empty positions, with a corresponding reduction in the number of double bonds. Typical commercial hydrogenation is partial in order to obtain a malleable mixture of fats that is solid at room temperature, but melts upon baking (or consumption). In most naturally occurring unsaturated fatty acids, the hydrogen atoms are on the same side of the double bonds of the carbon chain (cis configuration — from the Latin, meaning .
However, partial hydrogenation reconfigures most of the double bonds that do not become chemically saturated, twisting them so that the hydrogen atoms end up on different sides of the chain. This type of configuration is called trans, from the Latin, meaning . For example, oleic acid and elaidic acid are both unsaturated fatty acids with the chemical formula C9. H1. 7C9. H1. 7O2.
It is the configuration of this bond that sets them apart. The configuration has implications for the physical- chemical properties of the molecule. The trans configuration is straighter, while the cis configuration is noticeably kinked as can be seen from the three- dimensional representation shown above. The trans fatty acid elaidic acid has different chemical and physical properties, owing to the slightly different bond configuration. It has a much higher melting point, 4. Instead, the goal is to decrease the number of double bonds and increase the amount of hydrogen in the fatty acid. This changes the consistency of the fatty acid and makes it less prone to rancidity (in which free radicals attack double bonds).
Production of trans fatty acids is therefore an undesirable side effect of partial hydrogenation. Catalytic partial hydrogenation necessarily produces trans- fats, because of the reaction mechanism. In the first reaction step, one hydrogen is added, with the other, coordinatively unsaturated, carbon being attached to the catalyst. The second step is the addition of hydrogen to the remaining carbon, producing a saturated fatty acid. The first step is reversible, such that the hydrogen is readsorbed on the catalyst and the double bond is re- formed.
The intermediate with only one hydrogen added contains no double bond and can freely rotate. Thus, the double bond can re- form as either cis or trans, of which trans is favored, regardless the starting material.
Complete hydrogenation also hydrogenates any produced trans fats to give saturated fats. Researchers at the United States Department of Agriculture have investigated whether hydrogenation can be achieved without the side effect of trans fat production. They varied the pressure under which the chemical reaction was conducted — applying 1. Pa (2. 00 psi) of pressure to soybean oil in a 2- liter vessel while heating it to between 1.
The standard 1. 40 k. Pa (2. 0 psi) process of hydrogenation produces a product of about 4. Blended with unhydrogenated liquid soybean oil, the high- pressure- processed oil produced margarine containing 5 to 6% trans fat. Based on current U. S. Measurement techniques include chromatography (by silver ion chromatography on thin layer chromatography plates, or small high- performance liquid chromatography columns of silica gel with bonded phenylsulfonic acid groups whose hydrogen atoms have been exchanged for silver ions). The role of silver lies in its ability to form complexes with unsaturated compounds.
Gas chromatography and mid- infrared spectroscopy are other methods in use. Presence in food. CLA has two double bonds, one in the cis configuration and one in trans, which makes it simultaneously a cis- and a trans- fatty acid.
These partially hydrogenated fats have displaced natural solid fats and liquid oils in many areas, the most notable ones being in the fast food, snack food, fried food, and baked goods industries. Hydrogenation increases product shelf life and decreases refrigeration requirements.
Many baked foods require semi- solid fats to suspend solids at room temperature; partially hydrogenated oils have the right consistency to replace animal fats such as butter and lard at lower cost. They are also an inexpensive alternative to other semi- solid oils such as palm oil.
These partially hydrogenated fats have displaced natural solid fats and liquid oils in many areas, the most notable ones being in the fast food, snack food, fried food, and baked goods industries. Up to 4. 5% of the total fat in those foods containing artificial trans fats formed by partially hydrogenating plant fats may be trans fat.
High- fat dairy products such as butter contain about 4%. Margarines not reformulated to reduce trans fats may contain up to 1. In 1. 99. 9, reported percentages of trans fats (compared to total fats) in human milk ranged from 1% in Spain, 2% in France, 4% in Germany, and 7% in Canada and the United States.
In the early 2. 1st century, non- hydrogenated vegetable oils that have lifespans exceeding that of the frying shortenings became available. For example, an analysis of samples of Mc.
Donald's French fries collected in 2.