Effects of Continuous Deep Fat Frying on the Physical and Chemical Properties of Assorted Brands of Edible Cooking Oils Sold in Metropolitan Kampala

Deep fat frying is not novel, but a classical antiquity culinary technique preferred chiefly for its swiftness, amenity, conferment of a crisp texture, attractive sensorial and organoleptic qualities and thus delectableness of the fries. Regrettably, repeated use of oils for frying impacts the storage life and nutritional suitability of fries. This concerted study investigated the effects of continuous deep frying on physicochemical properties of ten brands of edible cooking oils: Fortune Butto, Roki, Tamu, Best Fry, Golden Fry, Mukwano, Sunny, Sunvita, Sunlite and Sunseed used in Kampala, Uganda. The color value (CV) and the acidification of the oils as free fatty acid (FFA), peroxide value (POV), paraanisidine value (AnV) and iodine adsorption value (IV) before and between ten successive deep-frying using potato chips were determined. The possible reuse of the oils was estimated from the frying round when a quality criterion surpassed the specifications for edible oils. For fresh oils, the mean statistical parameter readings were: CV (0.4R 3.4Y-7.7R 70Y), % FFA (0.0430-0.1508), POV (0.5951-6.6134 meqO₂/Kg), AnV (0.90-4.30) and IV (57.62-128.35gI₂/100g). By the tenth fry, the values were respectively 3.0R 23Y-20.4R 70Y, 0.2286-0.4817, 11.1138-15.7525 meqO₂/Kg, 10.31-22.16 and 53.66-126.03 gI₂/100g. Reuse of the oils for continuous frying of potatoes on the same day can be done only up to 7 times on average for hard oils and 6 times for soft oils.