Amounts of malondialdehyde do not accurately represent the real oxidative level of all vegetable oils: a kinetic study of malondialdehyde formation

Summary Malondialdehyde ( MDA ), a widely used oxidation indicator for both lipid and edible oil, has been suggested to be genotoxic and cytotoxic, thus attracting increasing attentions about its formation and exposure assessment. In this study, kinetics of MDA formation in vegetable oils and model oils were investigated by high‐performance liquid chromatography. Results showed MDA contents firstly increased rapidly then kept to a plateau over time in both reaction systems at 100, 140 and 180 °C, significant temperature‐dependent of MDA formation was observed. The rate constant and activation energy ( E a ) were calculated from the fitted pseudo‐first‐order model and Arrhenius equation. E a of MDA ‐formation was much lower in linseed oil, corn oil and rapeseed oil, indicating the higher degree of unsaturation resulted in the greater susceptibility to MDA formation. Besides, MDA content was inappropriate to assess the oxidation of palm oil and camellia oil possessing high level of saturated and/or monounsaturated fatty acid.