Analytical Investigation of oxidative deterioration of Sunflower Oil stored under different conditions

Abstract

A comprehensive study was carried out to investigate the extent of changes in sunflower oil under auto-, and -photo-oxidation conditions. Freshly prepared refined, bleached and deodorized (RBD) samples of Sunflower oil (SFO) were subjected to auto- and photo-oxidation. The free-fatty acid (FFA) contents of the auto- and-photo- oxidized samples increased from 0.056 to 0.290% and from 0.056 to 0.369%, respectively. The relative increase in the values of RI (40oC), Peroxide value, P-anisidine, conjugated dienes, conjugated trienes of the auto- and- photo- oxidized samples were found to be 1.4635-1.4671 and 1.4635-1.4672, 0.85-7.09 and 0.85-17.3 meq/kg, 1.45-10.03, 1.45- 17.16, 0.09-15.5 and 0.09-19.3, 0.15-13.4 and 0.15-15.5, respectively. The iodine values were found to decrease from 139-127.5 and 139-123.3 for auto- and- photo- oxidized samples, respectively. From the results of various investigated parameters, it was concluded that the oxidative deterioration level of the photo-oxidized SFO samples is more as compared to that of auto- oxidation. Based on this study, it is proposed that efforts should be made to minimize the hazard of photo-oxidation during the transportation and storage of such oils.