Physicochemical Evaluation of Used Frying Oils Through Determination of Saponification, Acid, Peroxide, And Iodine Values

Abstract : This study investigates the degradation of frying oils used in local food establishments through the analysis of key quality parameters. Oil samples, collected after frying common food items such as samosas, Manchurian, chicken, medu vada, jalebi, and momos for prolonged periods (8–9 hours), were examined. Palm and vegetable oils were analysed for acid value, saponification value, peroxide value, and iodine value using standard titrimetric techniques. Acid-base titration methods were applied for acid, peroxide, and saponification values, while iodometric titration was used for iodine value. The comparative assessment highlights the chemical changes occurring in reused oils, emphasizing the necessity of regular monitoring to ensure safety and suitability for continued use in food preparation.