RESUMEN
Nowadays, fortified vegetable oils with vitamin D3 are widely available in different countries and are consumed daily. The reduction rate of added vitamin D3 in fortified canola oil during heating process, the changes in oxidative status, and the thermal kinetic degradation of vitamin D3 in the fortified oil were investigated. For this purpose, canola oil was fortified at two levels of vitamin D3 with 5.625 µg/mL (low concentration or LC) and 13.585 µg/mL (a high concentration or HC). Samples were heated isothermally at 100, 150, and 180 °C for 30 min. The vitamin D3 concentration was determined by the high-performance liquid chromatographic method. The retention of vitamin D3 in samples treated at 100 °C for 30 min showed no significant reduction. Samples treated at 150 and 180 °C depending on the initial concentration showed the retention of 67.5% to 72.97% and 33.16% to 40.35% of vitamin D3 , respectively. An inverse relationship was found between the increment of lipid oxidation products (peroxide and anisidine values) and the retention of vitamin D3 . Kinetic parameters such as rate constant, activation energy, decimal reduction time, and quotient indicator were also calculated. An Arrhenius relationship was used for the assessment of temperature dependence of vitamin D3 degradation. Activation energies for vitamin D3 in LC and HC between 100 and 180 °C were found to be 44.01 and 38.77 kJ/mol, respectively. PRACTICAL APPLICATION: The oil can be fortified with vitamin D3 at low cost and offers a good bioavailability. A high-temperature cooking method may not be appropriate for the fortified products containing high lipid content.