The oils and fats are one of the major constituents of our food since pre-historic time and are also used as a source of heat and light.These are used for frying different foods.Sunflower oil is one of the most important vegetable oils employed for deep- frying.It has been used in the cooking of food such as meat,fish,doughnuts, potatochips,French fries,snacks etc at home, in restaurants and in industry.The frying substantially changes the physio-chemical properties of oil.This paper provides an indepth study on the variations in properties of sunflower oil upon deep frying and health impacts of using frying oil continuously.

Keywords : Deep-Frying, Oil, Refractive Index, TPC, Fatty Acid Profile, Transfat, Peroxide Value, Iodine Value Etc.