Aroma compounds of oxidised sunflower oil and its oil-in-water emulsion: volatility and release under mouth conditions

The influence of medium composition on the release and volatility (vapour/l iquid partitioning) of volatile lipid oxidation products was studied in ord er to explain the differences in composition of volatiles released from oxi dised sunflower oil and its 40% oil-in-water emulsion in a model mouth syst em. Volatile compounds were analysed by gas chromatography combined with fl ame ionisation detection and mass spectrometry. Larger amounts of volatiles , formed during oxidation. were released from the emulsion than from the bu lk oil. Differences in release influenced the results as well as the partit ioning, but showed contrary effects. Added reference compounds were release d in larger quantities from the oil than from the emulsion in the model mou th, and higher vapour/liquid partitioning values were obtained for the emul sion in comparison with the oil. In addition, water and saliva components i nfluenced the release of reference compounds in the model mouth and the par titioning, giving different results for the oil and the emulsion. In conclu sion, differences in the release of volatile compounds due to medium compos ition influenced the composition of the volatile lipid oxidation products o f sunflower oil and its emulsion, as well as the lipid oxidation rate.