Thermal analysis and antioxidant activity of oil extracted from pulp of ripe avocados

Avocado oil has attracted a growing interest in human nutrition and cosmetic or pharmaceutical industry; the lipid content composed mainly monounsaturated fatty acids and can exert many cardiovascular benefits and also other important functions as the prevention of cancer. Chile is one of the leading producers of avocado oil, although its production volume is small compared to other oils. Due to the importance of this oil, the oxidative stability and the relationship between the antioxidant capacity and its protection against the induced thermal oxidation were evaluated, considering their different fatty acid composition and the total phenolic content. The results showed a high content of monounsaturated fatty acid with a percentage of 69.4%, and the amount of polyunsaturated and saturated fatty acids was 16.6 and 14%, respectively. The TG and DTG curves in the temperature range of 200-600 A degrees C showed a thermal oxidative decomposition process with five consecutive and simultaneous steps of mass loss of avocado oil, remaining thermally stable up to 176 A degrees C. The avocado oil has a lower concentration of phenolic compounds than olive oil; nevertheless, the antioxidant activity was not so different, making a difference the presence of tyrosol and hydroxytyrosol in the olive oil. This study shows the high content of monounsaturated fatty acids and a good thermal stability, which correlate with the antioxidant capacity of the avocado oil, making this oil a good alternative for human nutrition or for cosmetic purposes.