Each type of oil has what is called a "smoke point." The smoke point is the specific temperature at which the oil starts to break down…or in more technical terms, its molecular structure begins to change. These molecular changes result in changes in flavor, as well as changes in nutritional value…specifically, the nutritional value of the oil starts to degrade; changing what once may have been considered an especially healthy oil (such as Olive or Flaxseed which is rich in Omega-3s), into one that is unhealthy.
If you’re cooking over high heat, don’t choose olive oil. Olive oil has a lower smoke point—the point at which an oil literally begins to smoke (olive oil’s is between 365° and 420°F)—than some other oils. When you heat olive oil to its smoke point, the beneficial compounds in oil start to degrade, and potentially health-harming compounds form.
Stick to the poli-board, you are way out of your league here.
quote:Virgins & Extra virgins, I use for sauces & dressings. However, even using lesser quality olive oils for cooking, the temperature still needs to be kept below a certain point. Any olive oil heated to 400 degrees will break down the healthy compounds of it into not so healthy ones.