1f:T4ee,The emergence of primary and secondary oxidation products in New Zealand extra virgin olive oil during accelerated thermal oxidation was measured and correlated with the concentrations of 13 headspace volatile compounds measured by selected ion flow tube mass spectrometry (SIFT-MS). SIFT-MS is a mass spectrometric technique that permits qualitative and absolute quantitative measurements to be made from whole air, headspace, or breath samples in real-time down to several parts per billion (ppb). It is well-suited to high-throughput analysis of headspace samples. Propanal, hexanal, and acetone were found at high concentrations in a rancid standard oil, while propanal, acetone, and acetic acid showed marked increases with oxidation time for the oils used in this study. A partial least-squares (PLS) regression model was constructed, which allowed the prediction of peroxide values (PV) for three separate oxidized oils. Sensory rancidity was also measured, although the correlations of headspace volatile compounds with sensory rancidity score were less satisfactory, and too few results were available for the construction of a PLS regression model. A fast (approximately 1 min), reliable method for prediction of olive oil PVs by SIFT-MS was developed.20:T41b,In this study, antioxidant activity and protective effects of Teucrium polium extract in stabilizing of canola oil during frying were tested and compared to synthetic antioxidant, BHA. Total phenolic, α-tocopherol, flavonoid, and condensed tannin content of Teucrium polium extracted by ethanol ultrasound-assisted were 60.90 mg/g, 103.66 μg/ml, 4.36 mg/g, and 3.77 mg/g, respectively. Moreover, IC₅₀ of the extract was 924.21 ppm. Canola oil samples containing 200, 600, and 1,000 ppm of the extract were heated at 180˚C for 30 hr and compared with BHA. Progress of oil oxidation was determined by measuring their peroxide value (PV), acid value (AV), iodine value (IV), carbonyl value (CV), color index (CI), conjugated diene value, and total polar compounds (TPC). The results showed that the extract was capable of retarding oil oxidation and deterioration significantly (p < .05) at all concentrations during frying. So, Teucrium polium extract can be used as natural antioxidant to retard oil oxidation.

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