Investigation of thermal stabilities of sesame oil and its blend with canola oil and palm olein

Oxidation is an important factor for decaying oil, that one way to prevent oxidation is Oils blend. In the present work, thermal stability and some physicochemical features were evaluated for sesame, canola, palm olein oils and their blends in different ratios. In the first step, fatty acid profile of the individual oils were determined by a GC. The amount of Acidity based Oleic acid by titration method and as well as conjugated diene and triene values changes were measured using an UV spectrophotometer by absorbance at 232 nm and 268 nm respectively, during the heating process at 170 oC for 18 h. The higher SFA (45.5 %), MUFA (69.4 %) and PUFA (44.01 %) were determined for palm olein, canola and sesame oils, respectively. According to the results, the highest hydrolytic deterioration was recorded for palm olein and canola oils. Also, the results showed that the acidity of the samples were lower than recommended value after heating the oil samples for 18 h . Base on the ultraviolet absorption results for the samples during the process, the blends of so:po:co (33.5:33.5:33.5), so:po (20:80) and so:po (50:50) were showed the highest thermal stability, while canola oil and the 20:80 and 30:70 blends of sesame and canola oils were showed the lowest thermal stability.