Key Odorants

The aroma of packed foods may be negatively affected during storage. Because a food aroma is often caused by a small number of volatile compounds (key odorants), the reason for a flavour change is most probably a change in the composition of key odorants. Packaging materials may be responsible for a change in odorant composition due to adsorption and diffusion processes.

Sensory investigations of coffee aroma have revealed that the aroma of roasted coffee, which was packed in three types of packaging materials and stored for 20 weeks, was significantly affected. Quantification of 11 key odorants in the three samples during the period of storage, however, showed no differences in the concentration profiles of the compounds. Therefore, the key odorants investigated are not the cause of the different aromas evaluated.

First investigations proved the generation of a compound which is undoubtedly responsible for the flavor difference. On basis of this result the aim of the study in 2000 will be to elucidate the reason for this flavor difference. This will be achieved by storing the same batch of coffee packed in different types of packaging materials.. Sensory investigations will be completed by aroma extract dilution analyses which is a useful tool to monitor the occurrence of off-flavor compounds.