How are we able to recognize foodstuffs by smell alone?

A new study has revealed how people recognize foodstuffs like strawberries, coffee or barbecued meat by just with its aroma.

Foodstuffs contain more than 10,000 different volatile substances. But only around 230 of these determine the odor of the food we eat and between just 3 and 40 of these key odors are responsible for encoding the typical smell of an individual foodstuff, which are then decoded by around 400 olfactory receptors in the nose.

The researchers found that the almost unlimited variety of food smells is based on 230 key odorants and each foodstuff has its own odor code comprised of a core group of between just 3 and 40 of the 230 key odorants, in specific concentrations, so these small groups of odorous substances are what give all kinds of foodstuffs from pineapple to wine to roast meat their unmistakable aromas.

Prof. Peter Schieberle from the TUM Chair of Food Chemistry said that the smell of cultured butter is encoded by a combination of just 3 key molecules but fresh strawberries have 12 and the Cognac is the most complex of all with 36 key molecules.

The chemical odor codes are translated into olfactory stimulus patterns when food is consumed. For this, the key odorous substances have to interact with one or more of the 400 olfactory receptors in the nose.

The mapping of odor codes opens up new possibilities for biotechnology applications and it will also lay the scientific groundwork for the next generation of aroma products, which use the potential of optimized biosynthetic pathways in plants for industrial-scale production of high-quality food odorants.

The study is published in chemistry journal Angewandte Chemie International.