Model studies on the influence of matrix type and storage environment on the stability of a model aroma mixture during storage

The objective of this study was to investigate the effect of oxygen in the storage atmosphere on the degradation of model compounds when present in water or a medium chain triglyceride (MCT) matrix. A model aroma compound mixture was prepared in oil (MCT) or water, and it was then stored under either an ambient air or argon atmosphere containing respectively ca. 20% and <0.5% residual oxygen. Samples were analyzed by SPME-GC/MS to determine the relative stability over time of different classes of aroma compounds. The low-oxygen atmosphere appeared to have a significant protective effect on sulfur compounds, aldehydes, and ketones in oil but a detrimental influence on pyrroles. Data showed little influence of the atmosphere for these compounds in water. In addition, the type of matrix had a significant effect (P < 0.05) on the stability of aldehydic, ester, and pyrrole compounds. These compounds were more stable in MCT than in water.