The chemical parameters and oxidative resistance to heat treatment of refined and extra virgin Moroccan Picholine olive oil

This paper presents the influence of heating on the content of saturated and unsaturated fatty acids and tocopherols of extra virgin and refined olive oil as well as some parameters describing the oxidative states of these oils. The results show that heat treatment causes a decrease in the nutritional quality of the two types of olive oil. The content of unsaturated fatty acids decreased significantly (p < 0.05) from 87.4% to 84.5% for refined olive oil, while no change was found for extra virgin olive oil. The content of saturated fatty acid did not change substantially for either type of oil. The heat treatment also caused a decrease in the tocopherol content that was more evident for the refined olive oil. This heat treatment results in an increase in free fatty acids that was more pronounced for refined olive oil. A similar result was found for the peroxide value.