Determination the effect of synthetic antioxidantson oxidative and thermal stability of oils

In this study, oxidative and thermal stability of bulk and frying oils such as safflower, sunflower oil oil, canola oil and cottonseed oil and with or without BHA, BHT, PG and TBHQ at levels between 50-150 ppm under accelerated conditions were investigated. Canola oil showed highest and safflower oil showed the lowest induction time among bulk oils with no antioxidants added (p≤0,05). When antioxidants are added and the oils analysed both rancimat test and schall oven test (p≤0,05). It was found that canola oil containing 90 ppm TBHQ and 130 ppm PG showed the best oxidative stability (p˂0,05). The results showed that TBHQ, PG and BHA were at slowing oxidation rate and therefore increasing oxidative stability in especially canola oil (p≤0,05). It was found that canola oil and cottonseed oil with no antioxidant added showed best thermal stability. When antioxidants are added it was found that canola oil containing PG and TBHQ had the longest time to reach critical TPM values. In conclusion, canola oil were best choice for the oxidative and thermal stability and PG and TBHQ at optimum levels of 90 and 130 ppm were the best synthetic antioxidants inceresing thermal stability of canola oil by extending the time to reach critical TPM values. It was concluded that PG and TBHQ as an antioxidant had a great potential for canola bulk and frying oils