Biotechnological production of aroma

Perception of the sensory qualities of food is determined by information transmitted to our brain via several sensory nerves such as the auditory, gustatory or trigeminal nerves, but it is undoubtedly the olfactory nerve that provides the most complex and diverse information. The olfactory nerve enables us to perceive signals (aromas) through the nose (orthonasal pathway), which gives us the smell of products, and through the retronasal pathway, once the food product is in the mouth, which is what we call the "aroma of a product".

The aroma of a food comes from a wide variety of chemical molecules, of diverse origins, capable of passing from the food into the surrounding air and interacting with the olfactory receptor, which is located in our nasal cavities, to create a signal perceived by our brain. This mechanism is more or less the same for all individuals. If this receptor lacks a receptor protein, perception may be weaker, or even absent (anosmia). In extreme cases, following trauma, olfaction can be completely lost. On the other hand, with training, we may be able to recognize certain aromatic notes and put a name to a perceived note by comparison with experienced products. This training is necessary to perform a descriptive sensory analysis of a food. It's a game to which wine lovers, for example, are accustomed but which, unconsciously, will determine the pleasure of eating or drinking.

The importance of olfactory perception stems from the link between the perceptual system and another part of our brain, in which information about experiences made and interpreted is stored. These experiences are acquired through childhood and culture. This makes olfaction a very important sense as a warning signal of toxicity, to which we must associate food aversions but also, on the other hand, the attractive signals that partly determine food preferences.

This is why the entire food industry is interested in flavors, as they are one of the factors that determine the purchase of a product. The food industry in particular uses flavors to make a product more attractive, to give it a distinctive character that sets it apart from other products on the market... So much so that, since the beginning of the 20th century, a major industry dedicated to the production of flavors has developed to meet the needs of the food industry. Most of these manufacturers have developed parallel applications for these products in the perfume and food industries. These companies (Givaudan, Firmenich, Symrise, IFF, Mane...) are little known to the general public, as their customers are other companies.

Let's take the example of coffee aroma. A mixture of around 1,000 different chemical structures is responsible for the variety of coffee aromas....