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Comparison of the oxidative stability of cold-pressed rapeseed oil using Pressure Differential Scanning Calorimetry and Rancimat methods

Research paper by Edyta Symoniuk, Katarzyna Ratusz, Krzysztof Krygier

Indexed on: 03 Nov '16Published on: 02 Nov '16Published in: European Journal of Lipid Science and Technology



Abstract

Oxidative stability of cold-pressed rapeseed oil was determined using two accelerated methods—Pressure Differential Scanning Calorimetry (PDSC) and Rancimat. Tests were carried out at six different temperatures (90–140°C), and the induction time (PDSC τmax, Rancimat τon) was a result. Based on the induction times, the Arrhenius equation and the activated complex theory, frequency factors (Z), constant reaction rate (k) for all temperatures, activation energies (Ea), Q10 numbers, activation enthalpies (ΔH‡), and activation entropies (ΔS‡) for cold-pressed rapeseed oils oxidative stability were calculated. The activation energy values of rapeseed oil oxidation in PDSC and Rancimat method ranged from 86.71 to 90.54 kJ mol−1 and from 75.73 to 77.64 kJ mol−1, respectively. The Q10, ΔH‡, and ΔS‡ values for analyzed rapeseed oil were between 2.00 and 2.07, 83.48 and 87.31 kJ mol−1, −61.30 and −51.40 J molK−1 calculated for PDSC measurements, and from 1.84 to 1.86, 72.50 to 74.41 kJ mol−1, −66.30 to −60.84 J molK−1 for Rancimat measurements, respectively.Practical applications: This research present the differences in the oxidative stability of cold-pressed rapeseed oil using PDSC and Rancimat method. The results of the PDSC test may be recommended as an appropriate objective method for assessing the oxidative stability of cold-pressed rapeseed oil. Also, results of kinetic oxidation parameters may be helpful to predicting the oil oxidative stability at different temperatures of oxidation process.The study evaluate the oxidative stability of cold-pressed rapeseed oils using Pressure Differential Scanning Calorimetry (PDSC) and Randimat method. The research shows a correlation (r = 0.9975) between two accelerated methods (PDSC and Rancimat) of assessing lipid oxidative stability.