RELATIONSHIP ACID COMPOSITIONS AND THERMAL STABILITY OF OLIVE OILS

Background: Fatty acids are one of the most important compounds in edible oils. Oils stability depends on the composition of fatty acids. The purpose of this study was to investigate the relationship between fatty acid compositions on the thermal stability in extra virgin olive oils. Methods: Eight samples of olive oil were tested in this study. Oils were heated at 120 ° C for 4 h to evaluate the thermal stability, were sampled every 2 hours. Fatty acid composition, Peroxide value, Anisidine value, Totox value, was conducted in accordance with Iranian national standards. Results: Results showed that oleic acid, the major fatty acid in olive oil, its value is between 69 to 74 percent. Between Palmitoleic acid and Totox index in second time (r=0.786) and Fourth Time (r=0.762), and between linoleic and Totox index in second time (r=0.643) and Fourth Time (r=0.786) there was a significant relationship. But between oleic acid and Totox index in Fourth Time (r=0.833) is a significant inverse relationship. Conclusion: Interpretation of the results suggests that linoleic acid and palmitoleic in extra virgin olive oil are decrease in thermal stability. But, Oleic acid increases the stability of the oils in during heat treatment process.

EDIBLE OIL, FATTY ACID COMPOSITION, THERMAL STABILITY