Interaction of terpenyl esters and polydimethyl siloxane with tocopherols in frying oil degradation

GERDE JOSE A.; HAMMOND EARL G.; WHITE PAMELA J.

Seattle, WA, USA

Conferencia; 99th American Oil Chemists' Society Annual Meeting & Expo; 2008

American Oil Chemists' Society

The protective effect of terpenyl esters and polydimethyl siloxane (PDS) in vegetable oil held at frying temperature has been previously demonstrated. In the current work, soybean oil containing 0.1 % of linalyl oleate (LO), menthyl oleate (MO), menthyl caprate, menthyl stearate or 5 ppm of PDS were heated at 180 °C for 32 hr, and the oil degradation monitored. Fatty acid compositions were determined at selected times and the linoleic to palmitic acid ratios were calculated. The slopes of the logs for this parameter decreased as a consequence of oil degradation. Oil with added PDS had a slope of -0.004, whereas all other treatments had slopes ranging from -0.0181 for oil with added MO to -0.0199 for oil with no additives. For LO, the rate of degradation increased with increasing surface-to-volume ratios. Further, tocopherol concentrations were determined and their degradation rates calculated to evaluate the impact of their disappearance on oil degradation as related to the additives.