Oils and fats for commercial frying applications can lead the changes caused by oxidation, polymerization, or hydrolysis during high-temperature processing. Deep frying is one method which involves submerging the food in hot oil. During oxidation can lead to the formation of potentially toxic oxidation products. This lipid per oxidation products generates that may be harmful to human health and it is necessary to monitoring of the frying oil quality degradation, therefore, is an important issue for both food frying operators and food control/regulatory agencies. In this study, The changes in the physicochemical properties of eight different brands of sunflower oils were analysed (before and after frying) using standard procedures of AOAC and AOCS. The experimental results obtained that,RI and specific gravity and colour were in the range of 1.4658-1.4720,0.9018-0.8848 and1.82-16.6 before and after frying. AV and PV were ranged between 0.22-0.54 in fresh oils,0.85-1.21in after frying and 2.4-4.1and 8.18- 13.15 mg KOH/g before and after frying oil while SV and EV were ranged between 189.98-193.12 and 189.62- 192.67 mg KOH/g oil in fresh oils and in between 198.68- 202.18 and 197.71-200.97mg KOH/g oil in after frying oils respectively. P-AV and TV were in the range of 3.9- 5.01 and 8.79-13.21 in before frying while in case of after frying it is 9.16-13.15 and 25.52-38.55 meq/kg respectively. In general, after frying, RI, colour,AV,PV,P-anisidine and totox values were found higher and deviates codex standards and specific gravity and iodine values are lower than as compared with safety limit. The results showed degradation in the physico-chemical properties of the vegetable cooking oil after frying

Keywords : Sunflower Oils, Frying, Physicochemical and Oxidative Characteristics