The researchers goal was to find out which cooking oil can maintain its quality under high heat and repeated use. For the study they deep fried and pan fried raw potato pieces in four refined oils corn, olive, soybean and sunflower. They also re-used each oil 10 times.
They noted that different oils have a range of physical, chemical and nutritional properties that can degrade oil quality when heated and that some of these changes can lead to the formation of new compounds that are potentially toxic. They also learned that by-products of heating oil can lower the nutritional value of the food being fried.
- Sunflower oil degraded the fastest when pan fried at 356 degrees
- Olive oil was the most stable oil for deep frying at 320 and 374 degrees Fahrenheit
- For frying food, olive oil maintains quality and nutrition better than seed oils
Read more about olive oil benefits here.