Popular science, what is saturated fatty acid? What are unsaturated fatty acids? Saturated fatty acids are stable, because there are no unsaturated bonds, they are generally solid and are not easy to be oxidized, so they are resistant to high temperatures. Unsaturated fatty acids are unstable because they contain unsaturated bonds, so they are prone to lipid peroxidation and have poor high temperature resistance. Therefore, it is easy to see that lard is solid at room temperature and belongs to saturated fatty acid, while vegetable oil is mostly liquid and belongs to unsaturated fatty acid. Some people think that eating lard is not good, so they only eat vegetable oil. In fact, this is not correct. Let's have a look!
Which is healthier, lard or vegetable oil? Many people have misunderstood. It turns out that saturated fatty acids are rich in meat, whole milk powder and cheese. Excessive intake of saturated fatty acids will increase the total cholesterol and low-density lipoprotein cholesterol of human body, so you can't eat a single animal oil for a long time. Therefore, it is suggested that the amount of animal fat eaten every day should be within 65,438+00% of the total amount of oil in one day. So far, there is not enough evidence that saturated fatty acids will increase the risk of cardiovascular and cerebrovascular diseases, so we can't kill saturated fatty acids with one stick. Diet should not be too single, and diversification can ensure comprehensive nutrition and health.
Improper cooking will only threaten your health. According to the research of American scientists, corn oil, sunflower oil and other oils rich in polyunsaturated fatty acids will produce a large number of aldehyde carcinogens if cooked improperly. For a common example, the content of carcinogenic aldehydes in fish and chips we often eat is hundreds of times higher than the relevant standards of the World Health Organization.
Olive oil, lard, butter or coconut oil, etc. These high-temperature resistant saturated fatty acids rarely produce harmful substances, and the proportion is greatly reduced. Therefore, in daily life, especially when cooking in various ways, there is no need to choose too single oil. Saturated fatty acids and unsaturated fatty acids should also live together.
No matter how good oil and lampblack are, they are unacceptable. Modern people's living standards have improved, and they pay attention to food and clothing. Some kitchen spices also pay attention to high-grade and ultra-high-grade, and oil is even more demanding. However, no matter how good the oil is, it is necessary to choose appropriate cooking methods and diversity of diet to reduce the intake of lampblack. Exposure to oil fume will not only increase the prevalence of respiratory system, but also lead to the decline of pulmonary ventilation function. So in the process of cooking, we should pay attention to the following points.
1, don't wait until the oil burns and smokes before cooking;
2, don't use cooking oil repeatedly, that is, you can't heat it repeatedly;
3. It is best to use a range hood and a smokeless pan;
4. If cooking produces lampblack, smoke should be discharged in time to avoid prolonged inhalation.
In short, it is better to choose the right oil, not too single, and change it frequently. It is recommended to buy small packages to avoid high temperature or long-term storage deterioration. In addition, we should control our daily intake and try to eat less fried food. If there are three people in a family, about 2.5L of oil per month is enough. It is recommended to buy small barrels of oil, and then buy other kinds of oil the next month, which is more convenient and healthier.