Lutein is Four Times More Stable in Sunflower Oil than Olive Oil at 40 °C

Abstract

The thermal degradation of lutein is investigated in refined sunflower and olive oils at a selected temperature (40 °C) for 3 months. All experiments are performed with lutein (6 mg ml−1) that is obtained from marigold flowers. Samples of the pigment in oil are incubated at 40 °C for up to 3 months and each month, the amount of lutein is monitored by a spectrophotometric method. A kinetic analysis of the data shows that thermal degradation is in accordance with the first‐order kinetics. The k values of lutein degradation in sunflower oil and olive oil are estimated to be 44 × 10−4 and 186 × 10−4, respectively. In the presence of vitamin E (15 mg ml−1), the k values are decreased and reach 24 × 10−4 and 72 × 10−4 in sunflower and olive oils, respectively. These results suggest that lutein is approximately four times more stable in sunflower oil than olive oil. Practical Applications: The obtained degradation kinetics of lutein in olive oil and sunflower oil under different thermal conditions can be used for designing pharmaceutical formulations with high stability and bioavailability in the future. In order to assess the degradation behavior of the lutein in oily media, a treatment is performed at 40 °C for 3 months and UV‐visible spectroscopy is performed for qualitative analysis.