Comparative study of Argan and other edible oils stability under accelerated oxidation

Abstract

Objectives: The study aimed at assessing the oxidative stability of the commercial Argan oil compared with those of high culinary use in Morocco, namely olive, rapeseed and sunflower oils. Methods/Analysis: The oils were subjected to two parallel accelerated oxidation tests, Swift and the oven test at 65 °C in air during 10 weeks. The evolution of oxidation throughout this period was followed periodically by simultaneously measuring the Peroxide Value (PV), the Refractive Index (RI) and absorption at 232 and 270 nm. Findings: Swift test showed that Argan oil was the most stable with a period of more than 32 hours to reach a peroxide value of 100 meqO2 /kg at 100°C. The storage at 60°C also revealed that Argan oil was more stable than the other oils. These results showed that the oxidative degradation depended on the initial chemical composition of oils, especially the content of polyunsaturated fatty acids and antioxidants. Improvement: The high stability of Argan oil was due to its particular fatty acid composition and its richness in tocopherols and phospholipids that act as antioxidants. The stability of Argan oil may also be enhanced by the Maillard reaction products resulting from the almonds roasting during the extraction. Keywords: Accelerated Oxidation, Argan Oil, Oxidative Stability, Phospholipids