Smoke point refers to the temperature at which the oil burns and begins to break down, emitting black smoke and unpleasant fumes. This will give the food a bitter taste, but even worse this can turn the oil into a potential carcinogen.
In the case of olive oil, there is a lot of confusion about the different varieties. The one you want to use for stir-frying may be labeled as light olive oil, which some may think is referring to its calories or fat content. Instead, it’s lighter in color and flavor, which is more neutral. This results from refining the oil, and heating it after the initial pressing of virgin olive oil. Other brands may call it extra light tasting olive oil, mild, or refined olive oil.
Of all the cooking oils, refined avocado oil has the highest smoke point: 500-570 degrees F. Unlike olive oil, your bottle of avocado oil may or may not state whether it is refined or unrefined, or if it is mild. After looking at several bottles on Amazon, they either provide the smoke point or state something like “works well for high-heat cooking like sautéing and frying” or “This oil is suitable for cooking at low, medium, and high heat.”
If an avocado oil is extra virgin or virgin this will be stated on the label. These oils will have a more distinct avocado flavor, but unlike extra virgin/virgin olive oil, they will have a higher smoke point and some may have a high enough one to be used in stir fries. You need to decide if you want that more intense avocado flavor. If they have a smoke point high enough for stir frying, this will be included on the label.
Just like refined olive oil and avocado oil, refined coconut oil is an excellent choice for stir frying. Its smoke point is 400 to 450 degrees, plus its neutral flavor doesn’t impart any coconut taste to the dish.
Last night I called a number of my favorite Chinese restaurants and inquired if they could use any of these healthy oils in their stir fries if requested. I know a number of restaurants that are very accommodating to how people are changing their diets, but these were still only using the oils they always have.