Oxidative Stability and Genotoxic Activity of Vegetable Oils Subjected to Accelerated Oxidation and Cooking Conditions

The oxidative stability and genotoxicity of coconut, rapeseed and grape seed oils were evaluated. Samples were submitted to different treatments: 10 days at 65 °C, 20 days at 65 °C (accelerated storage) and 90 min at 180 °C. Peroxide values and thiobarbituric acid reactive substances values were altered as a function of storage time, but their greatest changes were recorded in samples subjected to 180 °C. Fatty acid profiles did not show significant changes from the nutritional point of view. Volatile compounds showed the highest increases at 180 °C for 90 min (18, 30 and 35 fold the amount in unheated samples in rapeseed, grape seed and coconut oils, respectively), particularly due to the increment in aldehydes. This family accounted for 60, 82 and 90% of the total area in coconut, rapeseed and grapeseed oil, respectively, with cooking. Mutagenicity was not detected in any case in a miniaturized version of the Ames test using TA97a and TA98 Salmonella typhimurium strains. Despite the increment in the presence of lipid oxidation compounds in the three oils, they were not compromised from the safety perspective.