Kinetics of rapeseed oil oxidation by pressure differential scanning calorimetry measurements

Samples of rapeseed oils were oxidized at isothermal conditions in the cell of a pressure differential scanning calorimeter (PDSC). The experiments we re carried out under 1400 kPa oxygen pressure at a temperature in the range of 113-144 degrees C. From resulting PDSC exotherms the times to reach the peak maximum (tau(max)) were determined and used for the assessment of the oxidative stabilities of the samples. As PDSC exotherms were obtained at d ifferent temperatures, equations for extrapolation of the tau(max) values w ere proposed and activation energies as well as specific rate constants for oxidation were calculated.