Retronasal pathways

Fig. 8E.2 Schematic drawing showing the compositional differences between the extract obtained by a total extraction technique and the vapor phases reaching the pituitary during ortho or retronasal olfaction. The extract is enriched in polar volatiles that cannot reach the pituitary either by ortho or retronasal pathways...

Volatile compounds play a fundamental role in food seience and technology. In part, this is because they are released when foods and drinks are consumed, and are hence involved in aroma and flavour which are intimately linked to our enjoyment, palatability and perception of food. Aroma volatiles that reach the olfactory epithelium, via orthonasal and retronasal pathways, play not only a major role in our enjoyment of food (and drink), but also allow us to assess food quality or to detect subtle changes in food products as a result of modifications in ingredients and production. Volatile organic compounds (VOCs) are also emitted directly from food which can, for example, give us information about ripening processes (e.g. cheese or fruits) and the effects of storage. 

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