Comparative study on the stability of palm and local commercial oils during heating and frying processes

ABSTRACT

In this study, the development of heating and frying periods for both investigated oils conduced increased the acidity, saponification, peroxide, and TBA values; while unsaturation decreased. The increasing rates of peroxide and TBA values were higher in local oil than in the imported one, while the incremental rates of color and acid values were more remarkable in palm olein than local one, with the exception of the color of local sample which became more light at the end of heating period. Concerning the changes in the fatty acids composition, noticeable increases for stearic acid content [18 0] were obtained after heating and frying periods of 40 hours in both studied oils. Data also showed a decrease in the unsaturated fatty acids [18 1, 18 2], this decrement was more remarkable after frying process comparing with the heating process. Generally, the linoleic acid [18 2] showed the greatest decrease in concentration due to both thermal processes