Effect of rosemary, oregano and mint powders on oxidative stability and fatty acid profile of olive oil

Application of synthetic antioxidants is restricted due to possible toxic and carcinogenic products resulting from their decomposition. Thus، studies on natural antioxidant as an alternative to synthetic antioxidants would be of great importance. In this study، rosemary، oregano and mint powders were added to virgin olive oil at level of 2. 5% (w/w) and then stored for 7 days at 75°C in two forms of sealed and unsealed for further analysis. Free fatty acid content، peroxide value، cis-trans isomers and oxidative stability of samples based on peroxide value changes were measured. Results showed that an increase occurred in oxidative stability of virgin olive oil samples containing rosemary and mint powders. There was also no significant difference (p>0. 01) between control and spice treated samples in cis-trans fatty acids، SFA، MUFA، PUFA، TTFA، oxidative stability and MUFA/PUFA ratio.