Antiradical performance and physicochemical characteristics of vegetable oils upon frying of french fries: A preliminary comparative study

Results of physicochemical parameters and antiradical performance of vegetable oils during deep frying acting as an initial indicator for applying antiradical test for monitoring deep frying oils were compared. Refined and deodorized palm olein, sunflower oil and cottonseed oil were evaluated during intermittent frying of French fries on two consecutive days for 16 h with oil replenishing after 8 h. Changes in fatty acid profile were used to evaluate the alteration during frying. In the different systems, linoleic acid decreased while palmitic, stearic and oleic acids increased in the bath oil upon frying. Some physical and chemical measurements were chosen to evaluate the quality of frying media. Data showed that palm olein was stable as a frying medium compared to sunflower and cottonseed oils. This was evidenced in palm olein by the lower peroxide value, iodine value, color index, viscosity, total polar compounds and UV absorbances at 232 and 270 nm. In contrast, radical scavenging activities (RSAs) of the three vegetable oils were recorded during frying, wherein the results showed that palm olein had the highest RSA followed by sunflower and cottonseed oils, respectively. A proportional correlation and positive relationship existed between some physicochemical characteristics of vegetable oils and their RSAs. Thus, antiradical measurement could be used to quantify the oxidative and hydrolytic deteriorations of vegetable oils upon frying.