Fang Zhouzi: How terrible on earth the trans-fatty acid is

Fang Zhouzi: How terrible on earth the trans-fatty acid is
Fang Zhouzi: How terrible on earth the trans-fatty acid is
The security problem of the edible oil often will become the focus of the public opinion. The domestic media propagandizes the oil of underground drainage hotly, begin to propagandize " cream of plant " hotly also recently earlier on Or " hydrogenated oil " ,Say they contain rich amount of trans-fatty acid which endanger the health, are " listed in one of the greatest disasters in human food history by the expert " . Claim many American-European countries to begin, close down, ask, park to hydrogenated oil already now, but can still see at home that generally use the situation of hydrogenated oil. If really so? Before answering this question, what is the trans-fatty acid for one that we need prophets. The name sound on reverse side very much, but actually named according to its molecular structure, very neutral. The fat was combined with glycerine by fatty acid. The look of fatty acid looked like a long roller chain, stood up by carbon atom bunch of every one, there are hydrogen atoms that are bound with it on carbon atom. The valence of carbon atom is 4 prices, can form 4 covalent links with other atoms, hydrogen is a price. In middle carbon atom of the roller chain, because has already been bonded to two carbon atoms, can also combine two hydrogen atoms at most. If every carbon atom is bound with hydrogen atom as many as possible on the roller chain, we, on saying that planting fatty acid in this reaches the saturated condition, call that the saturated fatty acid. Animal fat and some vegetable oil (including coconut oil, palm oil and cocoa oil) Fatty acid saturated fatty acid. Under the saturated condition, carbon atom in the roller chain links up with the single bond each other. Two middle carbon atoms of roller chain of some fatty acid link up with one pair of keys each other, these two carbon atoms are both only bound with a hydrogen atom separately at this moment, in unsaturated state, we call this kind of fatty acid unsaturated fatty acid. With pairs of carbon atom that key link up, hydrogen atom of them lie in and one side two these, named the obeying type, this kind of fatty acid calls arranging fatty acid. If their hydrogen atom lies in both sides separately, is named the trans-fatty acid. Having hit one curved in the place of one pair of keys along the chain of type fatty acid, properties are unstable. The trans-fatty acid is a straight chain as saturated fatty acid, more steady. Here in the past, the fat eaten was mainly an animal fat, such as butter, cream, lard, they are rarer, expensiver. The vegetable oil is cheap, but fatty acid obeying fatty acid of the edible vegetable oil, they are very unstable, it is the liquid, and apt to be rotten, this is because free radical attacks one pair of keys in the roller chain to cause. At the beginning of the 20th century, German chemist William and Norman has thought of a solution, provide the hydrogen atom for one pair of keys in the vegetable oil, let them change and saturate, this course is called hydrogenating, the oil made out like this calls hydrogenated oil. If all one pair of keys is hydrogenated, saturation, turn into saturated fatty acid along type fatty acid. But usually there are only some pairs of keys the saturation, because of the reason of the craft, the structure of carbon atom of the pairs of keys both ends left changes in the project that is hydrogenated, their hydrogen atom has been turned the type into the type. In this way, hydrogenated oil contains a large amount of trans-fatty acid. After vegetable oil hydrogenate, turn into semi-solid, property steady difficult to be rotten, can use instead of the animal fat, and the price is much cheaper. Begin (instead of looking like what some domestic experts said, it is " good thing " that Americans do from Germany, Britain ),Hydrogenated oil has obtained and employ in the food processing industry extensively large-scale production quickly, used for making cake, flavoring agent and fried food. In the sixties of last century, people had already realized that had taken in the risk that the animal fat will increase cardiovascular vessel disease, the vegetable oil is comparatively healthier. At this time, use and hydrogenate the vegetable oil to replace the animal fat, is thought to be not merely in economy worthwhile, and more favorable to the health. Since the end of the eighties of last century, people have realized gradually that it is in fact bigger than the animal fat to hydrogenate the vegetable oil to healthy danger. This is mainly caused by trans-fatty acid among them, the risk of cardiovascular vessel disease which it increases, have higher saturated fatty acid than in the animal fat. A sign of the risk of weighing cardiovascular vessel disease is the content of cholesterol in the blood. There are two kinds of cholesterol, one is " bad " Cholesterol (lipoprotein cholesterol of low density) ,If its content is too high, will deposit in the artery tube wall slowly, form one kind of small tumours of porridge, cause arteriosclerosis. One kind is " It is good " Cholesterol (cholesterol of high density lipoprotein) ,Can prevent the forming of one kind of small tumours of porridge. The saturated fatty acid can increase " Bad " The content of cholesterol, has increased the risk of cardiovascular vessel disease accordingly. And except trans-fatty acid be able to increase " Bad " It is " good " that the content of cholesterol, still can reduce at the same time The content of cholesterol, has increased the risk of cardiovascular vessel disease doubly in other words. Not having this question along type fatty acid, some can reduce the risk of cardiovascular vessel disease instead along type fatty acid. Even when there is little quantity taken in (only accounts for 1%~3% of food heat) ,The risk to cardiovascular vessel disease of trans-fatty acid is still very obvious. The trans-fatty acid may have danger of other respects, but not proved conclusively yet. The trans-fatty acid is except providing energy for human body, there is no nutritive value, harmful instead, should then try hard to reduce and take in it, the less the better. The quantity that the suggestion of World Health Organization is the trans-fatty acid taken in every day don't exceed 1% of food heat, roughly don't be over 2 grams, eating a copy of French fries far exceeds this quantity (probably include 5~6 grams of trans-fatty acid) . So if often have a snack, the cake, fried food, snacks, it is too very difficult to exceed this limit. Quantity of trans-fatty acid that take in 5.8 grams one per capita every day such as U.S.A.. In this case, will consider whether to limit, forbid the use of the trans-fatty acid with strength of the government. But only specific cities such as specific countries such as Denmark,etc. and New York,etc. have taken action at present. Some producers is forced or changes the prescription voluntarily, put out " not including the trans-fatty acid " Products. But this kind of product, often instead of hydrogenating the vegetable oil with vegetable oil containing saturated fatty acid such as the animal fat or palm oil, likewise harmful to health. " cream of plant " It is no doubt not good, the natural cream had better be avoided too. While objecting to using trans-fatty acid, will recommend using obeying fatty acid, it is the healthy way.


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