There are many shortcomings and disadvantages. Recently, related media reported that trans fatty acids in foreign fast food can cause arteriosclerosis. A stone stirs up a thousand waves, and many people are extremely concerned about it. Both McDonald's and KFC use palm oil. Some experts point out that palm oil is the worst quality of vegetable oil, which contains trans fatty acids. Long-term consumption is not conducive to human health. Palm oil is widely used. The head of the Oil Crops Research Institute of Chinese Academy of Agricultural Sciences said that palm oil is squeezed from the palm fruit of oil palm trees, and it has been used as a natural food for more than 5,000 years. Palm oil is widely used in cooking and food manufacturing in the world. It is used as cooking oil, crispy fat and margarine. Judging from the composition of palm oil, its high solid triglyceride content keeps food stable without oxidation. In addition, palm oil is also suitable for hot climate, so it becomes a good seasoning for bread and cakes and is loved by food manufacturing industry. In addition, palm oil can also be used to make soap and many other kinds of products. Palm oil has a standard. There are several standards for palm oil used in different fields: palm oil with high melting point of 40 to 50 degrees Celsius is suitable for soap, cosmetics and other industries; Palm oil with a melting point of 30 degrees Celsius is suitable for margarine and cocoa butter. Palm oil with a melting point of 24 degrees Celsius is generally used for fried biscuits, instant noodles and other non-staple foods; Palm oil with melting point of 12 degrees Celsius or below is edible oil with certain nutritional value. However, palm oil on the market at present is generally palm oil with a melting point of 24 degrees Celsius, which is not suitable for long-term household use. Eating palm oil regularly is harmful. A related person from the Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences said that palm oil contains more than 50% saturated fatty acids, and its nutritional quality is worse than lard. When the temperature drops, it will condense into a white solid like lard. Long-term consumption of palm oil will lead to excessive intake of saturated fatty acids in human serum, which will lead to the increase of cholesterol, triglycerides and low-density lipoprotein, which will lead to cardiovascular and cerebrovascular diseases. The worst fatty acids in palm oil products are mainly divided into saturated fatty acids, monounsaturated fatty acids and polyunsaturated fatty acids. Both animal fat and vegetable oil contain saturated fatty acids. Its "low density lipoprotein cholesterol" and "triglyceride" are the main components leading to hypertension and atherosclerosis. Palm oil is the worst quality of all bulk vegetable oils, so it is said that its saturated fatty acid content is the highest, which is higher than that of lard (43%). The content of saturated fatty acids in other vegetable oils is much lower than that in palm oil. Sunflower seed oil is 1 1%, soybean oil is 15%, peanut oil is 19%, and rapeseed oil with low erucic acid content is only 7%, which is the lowest saturated fatty acid content in vegetable oil. The higher the saturated fatty acid content, the lower the nutritional value. Teach you a trick. In view of the practice of some domestic enterprises mixing palm oil into edible oil as inferior oil, experts in the industry remind consumers that the method of identifying whether edible oil contains palm oil is very simple. You can use its low temperature resistance to put edible oil into the freezer (10 degrees below) in summer. Once the white condensate is found, it means that the edible oil contains palm oil; In winter, the outdoor temperature is low, and if there is solidified body, it also means that palm oil is mixed in the oil. Some merchants selling edible oil will sell it at a discount when the weather gets cold, because they are worried that the edible oil mixed with palm oil (mostly blended oil) will be exposed as the temperature drops. (Xiao Ni) What is a little knowledge of trans fatty acids? Trans fatty acids are artificial fats. The so-called fatty acid is also the scientific name of fat and oil that everyone usually says. Among them, animal fat belongs to saturated fatty acid and vegetable oil belongs to unsaturated fatty acid, which exists in two forms, namely cis and trans: cis is liquid and trans is solid. Trans fatty acids, also known as artificial fats, can be obtained by partially hydrogenating vegetable oils. The role of (granular) trans fatty acids Compared with ordinary vegetable oil, trans fatty acids have the advantages of high temperature resistance, difficult deterioration and long storage time. One of the purposes of hydrogenation is to destroy some basic fatty acids to reduce the risk of oxidative decomposition. For example, a pack of simple candy may only be preserved for 30 days without hydrogenated fatty acids, but if hydrogenated fatty acids are used, the shelf life of the same product can be extended to 18 months. It is reported that trans fatty acids have been invented for more than 100 years and have been widely used in food processing industry since 1980s. It can change the fluidity of vegetable oil such as soybean oil, make it semi-solid and have a taste similar to butter and cream, and play a crisp role in frying food, making food more crisp. On the labels of biscuits, pineapple cake, instant noodles, egg rolls and other foods, the listed ingredients include hydrogenated vegetable oil, partially hydrogenated vegetable oil, hydrogenated fat, hydrogenated vegetable oil, solid vegetable oil, ghee, margarine and white cream, that is, trans fatty acids are contained. Trans fatty acids are bad cholesterol. The US Food and Drug Administration calls trans fatty acids "bad cholesterol". Studies have found that a large intake of trans fatty acids will increase the low-density lipoprotein cholesterol harmful to human body, reduce the high-density lipoprotein cholesterol beneficial to human body, and increase the risk of coronary heart disease. Excessive trans fatty acids will also increase the viscosity of human blood and easily lead to thrombosis. In addition, trans fatty acids also have adverse effects on infants and growing adolescents. Fetuses can absorb trans fatty acids through placenta, and newborn babies can absorb trans fatty acids through breast milk, which will affect children's absorption of essential fatty acids. At the same time, trans fatty acids will also have a negative impact on the growth and development of the central nervous system of adolescents. (Wei Li) Related News Experts in various countries generally believe that trans fatty acids are far more harmful to the human heart than any animal fat. It is based on more and more research findings that many countries have made relevant regulations on the application of trans fatty acids. ● Denmark explicitly prohibits the use of trans fatty acids in food. It is reported that Denmark is a country that explicitly prohibits the use of trans fatty acids in food. Its law stipulates that every100g of edible oil can only contain 2-5g of trans fatty acids, which is extremely low, which means that it is basically unusable. ● The United States requires foods to indicate the content of trans fatty acids. In the United States, the US Food and Drug Administration has formulated a new draft regulation on nutrition labeling of food packaging, which requires that the content of trans fatty acids be indicated in the nutrition tables of traditional foods and dietary supplements. ● Canada set up a task force on trans fatty acids In Canada, the government set up a task force on trans fatty acids to evaluate the risks and benefits of trans fatty acid substitutes. At present, prepackaged foods has been required to indicate the trans fatty acid content on the label, and other healthy substitutes are encouraged to replace animal oil and vegetable oil with high trans fatty acid content. China is preparing to apply for this project. At present, there is no corresponding standard for the content of trans fatty acids in China, and there is no method to detect trans fatty acids. It is reported that the National Institute of Nutrition and Food Safety is preparing to apply to the relevant departments for a project to study the detection standards and methods of trans fatty acids. Remind to control the total intake of edible oil and eat less pig, cattle and sheep oil and palm oil. Although the main source of fat is edible oil, food itself also contains oil, such as cheese, egg yolk, bacon, nuts, peanut butter and lean meat. In order to prevent excessive intake of oil, people should pay attention to reducing the intake of oil appropriately. Don't confuse edible oil with seasonings such as soy sauce and vinegar. Generally, 25 grams of cooking oil per day is enough. 750 grams of oil a month is a lot for a person. The rest of the oil comes from various foods, so the heat energy provided by oil will not exceed 30% of the total heat energy of the diet. Our cooking methods also need to be considered. Sometimes it is enough to use 25 grams of cooking oil a day, and sometimes it is not enough. These all need attention. Some people think that there is no taste without oil. If there is no taste, you don't like eating it. Therefore, if you eat too much oil, it should be specially controlled. Animal oils such as lard, butter and sheep oil are mostly saturated fatty acids, so eat less. The oil in instant noodles is palm oil. Although it is also vegetable oil, its composition is the same as lard and cream, and it contains a lot of saturated fatty acids. Eating instant noodles often can also lead to an increase in serum cholesterol, which is harmful to health. So instant noodles can only be eaten occasionally, not as dinner. In addition, eat little or no hydrogenated oil. After industrial processing, unsaturated fatty acids in vegetable oil will become saturated fatty acids after hydrogenation. For example, there is a thick layer of margarine on the birthday cake, some of which contain hydrogenated oil, which is not good for human body.