Which oil should you use if frying, stir-frying, or deep frying your food?
So let’s be clear; steaming, baking, or poaching your food without adding a lot of oil is generally preferable unless you desperately need the added fat in the oil to survive (malnutrition for example). Many of us do love the taste of oil fried food and if you are going to cook this way (I still stir-fry), which oil is the best? This study “Monitoring of Quality and Stability Characteristics and Fatty Acid Compositions of Refined Olive and Seed Oils During Repeated Pan and Deep- Frying Using GC, FT-NIRS, and Chemometrics”, (you can read it here… ) looked at olive, soy, corn, and sunflower oils and which produced the most harmful compounds when used for high temperature cooking.
I was happy and surprised that olive oil performed best. Happy because this is one of the healthiest oils to use in your kitchen anyway, and surprised because I had been misinformed in thinking that olive oil was really only safe when used cold pressed and unheated. Extra-virgin olive oil is still one of the best nutritionally and it is still preferable to avoid high temperatures.
The oils were used in repeated frying sessions at 160 and 190 degrees C and pan-frying potatoes at 180 degrees C. This study showed that olive oil had the least oxidative deterioration and all oil performed better at the lower temperature. Sunflower oil had the worst oxidative deterioration and production of trans-fatty acids with heat exposure.
Moral of the story: use olive oil. This study did not include coconut oil which is another good one to use in cooking.