Effects of microwave and conventional heating on the oxidative stability of corn oil enriched with different antioxidants

A. Baştürk
2019 Grasas y Aceites  
Four different corn oil samples including stripped (SCO, Control), refined (RCO), stripped corn oil enriched with rosemary extract (SCO+ROS) and ascorbyl palmitate (SCO+AP) were exposed to microwave (MWH) and conventional heating (CVH). For both heating methods, peroxide value (PV) and conjugated dienes increased at up to 230 °C, at which temperature hexanal (HEX) and conjugated trienes started to increase instead. Kinetic analysis revealed that PV and HEX formation were first ordered and the
more » ... action rate among the samples was as follows: Control > SCO+ROS > RCO > SCO + AP for PV and SCO + ROS > RCO > SCO+AP > Control for HEX. The unsaturated fatty acid contents of CVH and MWH treated samples showed 9.5 and 12.9% reduction in SCO, while they were 2.9 and 7.7% in RCO, 3.6 and 6.1% in SCO + ROS, and finally 4.0 and 4.8% in SCO + AP. It was concluded that MWH led to a more severe deterioration and that the antioxidant activity of ROS was superior to that of AP for both heating methods.
doi:10.3989/gya.1044182 fatcat:fhqbar7irzahlj6xiokiag6yka