Frying is one of the world’s most popular ways to prepare food such as fried chicken and french fries, as well as candy bars and turkeys.
Scientists report in American Chemical Society’s Journal of Agricultural and Food Chemistry that olive oil withstands the heat of the fryer or pan better than several seed oils to yield more healthful food.
Researcher Mohamed Bouaziz and colleagues note that different oils have a range of physical, chemical and nutritional properties that can degrade oil quality when heated.
He is from Laboratoire d’Électrochimie et Environnement in Tunisa.
Some of these changes can lead to the formation of new compounds that are potentially toxic.
By-products of heating oil can also lower the nutritional value of the food being fried.
The team of researchers wanted to find out which cooking oil can maintain its quality under high heat and repeated use.
The researchers deep- and pan-fried raw potato pieces in four refined oils — olive, corn, soybean and sunflower — and reused the oil 10 times.
They found that olive oil was the most stable oil for deep-frying at 320 and 374 degrees Fahrenheit, while sunflower oil degraded the fastest when pan-fried at 356 degrees.
They conclude that for frying foods, olive oil maintains quality and nutrition better than seed oils.
The scientists acknowledge funding from the Ministère de l’Enseignement Supérieur et de la Recherche Scientifique and the Ministère de l’Agriculture, Tunisia.