Evaluation of the stability of blends of sunflower and rice bran oil

Blends of sunflower oil (SFO) and rice bran oil (RBO) were evaluated for their stability. Additionally, known amounts of natural antioxidants extracted from RBO were added to SFO, and their protective effect was compared to that of the blends. The results found indicate that by raising the amount of RBO, from 10 to 50%, an increase of OLO, OLP, PPL, OOO, PPO, OPO, 18:1 and 16:0 occurred, followed by a decrease of LLL, LLO, and 18:2. These changes in fatty acid and triacylglycerol (TAG) composition led to an increase of the oil stability index at 120 °C and a reduction of polymer TAG formation in the heated blends at 180 °C during 8 h. A comparable protective effect of natural antioxidants to that of blending was observed in a 50 : 50 blend, by remarkably increasing the induction period.