Release of volatile oxidation products from sunflower oil and its oil-in-water emulsion in a model mouth system

The amounts secondary lipid oxidation products formed in vegetable oils, which are available for perception, are determined by both lipid oxidation rates and release from the matrix. In the present work, the influence of fatty acid composition and emulsification on lipid oxidation rates and release were determined during oxidation of vegetable oils at 60 °C. Volatile compounds were released from sunflower oil, a blend of sunflower and linseed oil, and from their 40 % oil-in-water emulsions in a model mouth system and were analyzed by gas chromatography-sniffing port analysis. Higher polyunsaturated fatty acid content and emulsification of the oil resulted in more odor active compounds and greater amounts available for perception. Higher concentrations in the oil phase of these samples revealed increased lipid oxidation rates. Reference compounds added to the samples demonstrated an increase in aroma release from the oil under mouth conditions for most of these compounds. In contrary, the higher static headspace concentrations of reference compounds were higher for the emulsion than for the oil.