Influence of Teucrium polium L. essential oil on the oxidative stability of canola oil during storage.

The susceptibility of Teucrium polium essential oil (EO) as an antioxidant for canola oil was studied. Major compounds of the EO were 11-acetoxyeudesman-4-α-ol (26.3%) and α-bisabolol (24.6%). Different concentrations (200, 600 and 1200 ppm) of EO and synthetic antioxidant BHA (200 ppm) were added to canola oil and incubated for 60 days at room temperature. Acid value (AV), peroxide value (PV), carbonyl value (CV), iodine value (IV), total phenolics (TP), total polar compounds (TPC) and oxidative stability index (OSI) of canola oil were determined. Antioxidant capacity of the EO was measured by DPPH and β-carotene-linoleic acid assays. Results exhibited that DPPH and β-carotene-linoleic acid experiment detections on the EO were analogous in high concentrations to those detected on BHA. Moreover, incorporated EO samples had better AV, PV, CV, IV, TP and TPC than control. EO at concentration of 600 ppm indicated higher antioxidant activity in canola oil compared with BHA.