Flavour release and perception from model dairy custards

The influence of composition on the rheological properties, on the static and in vivo aroma release and on the flavour perception in model systems of strawberry flavoured custard desserts was studied. Eight formulations were prepared varying in the concentration of starch (3 or 4%, w/w) and milk type (whole or skimmed) with or without κ-carrageenan (0.01%, w/w). Thickening agents (starch and κ-carrageenan) significantly modified the texture of the samples but behaved differently with regard to the release of the strawberry flavour. κ-Carrageenan did not affect the headspace nor the in vivo release of the volatiles in whole milk systems, but starch seemed to favour their release, especially ethyl hexanoate. A salting-out effect may be involved in the latter case. As far as milk type is concerned, it had a significant effect for both headspace and in vivo release of the volatiles, especially for the more lipophilic compounds. The sensory tests confirmed this, i.e. the samples formulated with skimmed milk had higher perceived flavour regardless of the starch and κ-carrageenan concentrations.