Food companies have come a long way in their ability to improve the properties of vegetable oils at the manufacturing level. There are refined and conditioned oils in the marketplace, including oils from hybrids that are high in certain types of fat such as monounsaturated fatty acids, which are less susceptible to damage from heating. If you are going to cook with oils, your best bet are those organically produced, high quality oils that have been specifically adapted for use in high heat cooking or oils that have naturally high smoke points, like avocado oil. But there may even be a better option...cooking without oils!
When you heat an oil to its smoke point, you have definitely inflicted a good bit of damage to the oil. This damage comes in several forms.
Damage To Nutrients In The Oil
* Heating causes loss of available nutrients contained in oils, including fat- soluble vitamins like vitamin E and phytonutrients that give oils their characteristic colors, smells and flavors.
* Heating oils can cause the formation of free radicals, highly reactive molecules that can damage the oil further by triggering unwanted oxidative reactions. Oil manufacturers actually assign a value (called a peroxide value, or PV) to the oils based on the amount of oxidative reactions occurring.
* Formation of unwanted aromatic substances (like polycyclic aromatic hydrocarbons or PAHs) in the oil that can increase our risk of chronic health problem including cancer.
The smoke point is a natural property of unrefined oils, reflecting their chemical composition. When oil is refined, the process increases the oil's smoke point; in fact, raising the smoke point is one of the reasons why the refining process is used. The chart below is an example of how refining increases the smoke point of oil.
OIL TYPE SMOKE POINT
Canola oil, unrefined 225 Degrees
Canola oil, semi-refined 350 Degrees
Canola oil, refined 400 Degrees
Safflower oil, unrefined 225 Degrees
Safflower oil, semi-refined 320 Degrees
Safflower oil. refined 450 Degrees
Soy oil, unrefined 320 Degrees
Soy oil, semi-refined 350 Degrees
Soy oil, refined 450 Degrees
Sunflower oil, unrefined 225 Degrees
Sunflower oil, semi-refined 450 Degrees
Sunflower oil, refined high-oleic 450 Degrees
There are several types of olive oil on the market:
* Extra Virgin: derived from the first pressing of the olives and has the lowest acidity level.
* Fine Virgin: also created from the first pressing of the olives, but it has an acidity level more than double that of extra virgin oil.
* Refined: unlike extra-virgin and fine virgin oils, which only use mechanical means to press the oil, refined oil is created by using chemicals to extract oil form the olives.
* Pure: a bit of a misnomer, it indicates oil that is a blend of refined and virgin olive oils.
The information on olive oils smoke point is, unfortunately, not very clear or consistent since different companies list different smoke points of their olive oil products; this variability most likely reflects differences in degree of processing.
So, consequently, damaged oils do not only occur at smoke point but can actually be damaged from heat long before its smoke point is reached. Exactly when does damage start to occur? The research is not entirely clear about this point,
So, in conclusion, it is best not to cook with heated oils. While steaming is a popular cooking method that doesn't use oils, there is another low-heat alternative by using broth to saute instead of oils. By adding healthy oils to vegetables, sauces and soups after they have cooked not only prevents the oil's exposure to high heat but allows you to enjoy more of the oil's wonderful flavor.
Here's to healthy sauteing without oils!!