What is the grade of cooking oil by what type? Is the higher the grade, the better the nutrition?

interviewed by Zhu Yi, Associate Professor, School of Food Science and Nutritional Engineering, Agricultural University of Chinacareful consumers may find that many of the edible oils on the market are now labeled with a level one, two, three, four four grades, which is divided according to what? Is the higher the grade the better nutrition?Zhu Yi, an associate professor at the School of Food Science and Nutritional Engineering at china Agricultural University, told the Life Times that according to the relevant national standards, according to the relevant standards, according to the degree of refining, peanut oil, soybean oil, corn oil and other vegetable oils are generally divided into one, two, three, four levels of four gradesThe higher the level, the higher the refining level, but does not mean that its nutrient content is more, on the contrary, from a nutritional point of view, the third and fourth grade oil sthe highdegree of refining of first and second-level cooking oil, with tasteless, light color, less fried vegetable smoke, low temperature is not easy to freeze and so on, while the purity is higher, the impurity content is less, usually applicable to higher temperature cooking, such as for frying, frying, dry frying and so onBut the refining process removed a lot of beneficial ingredients to the human body, such as vitamin E, carotene and so onThree-level and four-level cooking oil refining degree is low, only after a simple degluing, deacidization and other procedures, its color is darker, the cooking process is larger, the impurity content is also higher, but retainsome carotene, vitamin E and other nutrientsThree-level and four-level oil is not suitable for high temperature heating, more suitable for stews, soup and so onSome people like flavor, some people pay attention to nutrition, cooking oil level selection varies from person to personWhether it is primary oil or four-level oil, as long as it complies with national health standards, we can rest assured that you can choosein general, olive oil is divided into two categories: virgin olive oil and refined olive oilVirgin olive oil is extracted directly from fresh olive fruit, is yellow-green and contains antioxidants such as polyphenolsHowever, because it contains free fatty acids and polyphenols, chlorophyll and other unstable chemicals, so it is not suitable for long-term high temperature heating, suitable for cold cooking and other low temperature cookingRefined olive oil and other refined vegetable oil symnotry, after a series of degluing, deacidization and other procedures, remove impurities from the oil, antioxidants and flavor components are also removed most of the, but because of its low content of polyunsaturated fatty acids, better heat resistance, oxidation risk is small, suitable for fried vegetablesSource: People's