Physicochemical Characterization and Frying Quality of Canola and Sunflower Oil Samples

Summary: Frying quality of canola and sunflower oils was evaluated. Stimulated frying experiments were performed on oils with French fries as the fried food. Samples of oils were used to fry potato chips for four days. Physical and chemical characterization was carried out to determine the change during frying. Comparison of frying oil samples was then made with their control counterparts (i.e. oil samples without frying). There was a gradual increase in refractive index, viscosity, acid value and colour with time of frying. Iodine value decreased significantly with time of frying. Peroxide value first increased up to 12 h of frying and then decreased. Colour change and viscosity increase with increase in frying time. Amount of free fatty acid gradually increase during frying. Refined oil showed better performance than the crude oil due to the presence of impurities in the latter.