The heat treatment influences the physico-chemical and oxidative characteristics of coconut oil

Abstract

The objective of this study was to evaluate the effect of heat treatment on the profile of fatty acids, antioxidant capacity, lipid oxidation and physical-chemical characteristics of coconut oil. The analyzes were carried out with samples of the coconut oil in natura, heated to the “point of smoke” and used in the frying of potatoes. The fatty acid profile, the peroxide and acidity indexes, the malondialdehyde formation and the antioxidant capacity of the coconut oil were evaluated in the three conditions. The fatty acid profile did not differ in the different conditions of analysis; however, it can be observed that the acid value was significantly higher in the heated oil and used in frying. For the peroxide index, this increase occurred only in the heated oil. The formation of malondialdehyde was observed in all the samples, being higher in the heated oil, followed by the one used in the frying. The antioxidant capacity was lower in the samples submitted to heat (significant difference). It is concluded that the thermal treatments to which the coconut oil was subjected, were able to modify its physicochemical and oxidative characteristics. Considering the possible damages associated with the consumption of oils and degraded fats, we discourage the use of coconut oil subjected to high temperatures. We emphasize the importance of the creation of specific methodologies for the evaluation of the quality of oils and fats submitted to the heating, as it allows a better control of the nutritional and sensorial aspects of the oils destined for consumption.