Olive oil more stable and healthful than seed oils for frying food, study
Olive oil withstands the heat of the fryer or pan better than several seeds oils to yield more healthful food, according to new research from the University of Sfax in Tunisia in North Africa.
The study, published in the American Chemical Society’s Journal of Agricultural Food and Chemistry in September 2014, found that olive oil was the most stable for cooking with high temperatures.
Professor Mohamed Bouaziz and colleagues at the Laboratoire d’Électrochimie et Environnement, École Nationale d’Ingénieurs de Sfax, at the University of Sfax noted that different oils had a range of physical, chemical and nutritional properties that can degrade oil quality when heated. 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. Professor Bouaziz’s team wanted to find out which cooking oil could maintain its quality under high heat and repeated use.
The researchers deep- and pan-fried raw potato pieces in four different 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 concluded that for frying foods, olive oil maintains quality and nutrition better than seed oils.
The researchers acknowledged funding from the Ministère de l’Enseignement Supérieur et de la Recherche Scientifique and the Ministère de l’Agriculture, Tunisia.