When you buy cooking oil, pay attention to the label to see what grade it is. There are four grades, and the higher the grade, the higher the quality.
The first and second-grade oils are light in color.
This means that they are less concentrated than the other oils.
First-grade oil is more refined than second-grade oil. It has gone through many processes to make it taste light, look light, and have a high smoke point. Second-grade oil doesn’t have as many refinement processes and some nutrients are lost in the process.
Three or four colors of oil paint are very deep.
The third-grade oil is less refined than the fourth-grade oil, so it has a darker color and stronger aroma. However, it’s less refined, so it has a lower smoke point and larger cooking fumes. The third and fourth-grade oils have a lower refining degree, so they have more impurities, but they also contain some nutrients, like carotene and vitamin E.
Primary and secondary oils can be used in high-temperature applications.
Even if an edible oil is just a grade lower than the best quality oil, it is still safe to use. In fact, cooking at a high temperature, like when you stir-fry, may be best done with higher-quality oils. However, oils from the third and fourth grades should not be used for high-heat cooking, because they can damage food.
The grade of oil is good for lower-temperature use.
Edible oil is divided into two types: pressed oil and leached oil. Pressed oil is processed by physical pressure without any chemical additives, which is safe, hygienic, and pollution-free. Cold-pressed oil has a special label that indicates if the oil was processed this way. Leached oil is processed by using chemical solvents to extract the oil from the raw material, and the extraction rate is high, so the price is relatively cheap. However, leached oil is not as safe as pressed oil.
Chemical leaching extraction is a process that uses chemicals to remove substances from a substance.
If you want to eat healthy, the most recommended thing to do is to use cold-pressed edible oil. This type of oil retains all the nutrients in the raw materials, making it safer than other types of oils.