(31) Everybody its own, and again (part 3)

This post is the third in the taste serie, please do not hesitate to visit the website for more information, including the first two parts.

Smell is one of the two main components of taste. Of course, we look at the cheese first, but do we touch it or smell it then? I would not like to ask a child, even if the truth is spoken by child as we like to say in France, as more often than not the first thing that they would say is “whoa it stinks!”

So, let’s talk about smell.

“Whoa it Stinks!”

Now you understand the title of this chapter. It is a fact of life that a lot of prejudice is thrown at cheese in general; but we will deal about this aspect a bit later. This is all about legacy or custom.

Human olfactory cavity

Anyway, what can we say about smell?

The first thing, obvious, is that it is the only sense that has to deal with a non-concrete sensation. By this I mean to say that odours are not physically visible but are felt. Which in turn means that interpretation will play an important part of the process.

The Ethereal World

The sense of smell is one very important part of the body function. It is directly relied to the brain and analysed straight away. Its functions are not always easy to discern. This goes from early warning detector to mate selection; it affects our mood as well as our immune system and emotions. Average humans have from 6.5 to 10 million olfactory cells. However other mammals have usually more than 50 times this number.

Smell has played a very important role in the development of the specie at the early stage. Smell is a regulator concerned with our social and geopolitical environment. It helped us in assessing territories, social groups, sexual contacts and was used to detect predators and preys. Women will select their partner by selecting one with different genes as defined by the smell emitted by their body. The simple explanation is that by this selection they will have offspring with a reinforced immune system and will ensure the survival of their progeny.

The actual difference between the other mammals and humans is that we are the only one who has mastered the upright posture. The difference in olfactory resolution seems to be directly linked to this change of posture. Smell is directly linked to the frontal lobes of our brain. This area is associated with the higher logical process and is sought to have been at the start of the evolution of humans. The retro nasal capacity developed naturally by humans have led to a high capacity to distinguish complex odours and create taste recognition and interpretation.

From conception to eight years of age, our sense of smell progress to its maturity. After this age it is a question of memory and training which will make the difference, contrary to our other senses, smell is often more than not connected to emotional memories. Obviously, you need to be in good physical and mental condition. Zinc is the essential nutrient for good smell. Smoking reduces the ability to discern all smells and to identify them correctly. Another consideration of this fact is that this sense is primordial, it is the first sense that the brain fully develops.

Flavour that we feel is in fact a combination of the smell and the taste. Some smell can be evocative of a flavour without us eating. Brillat-Savarin (19th century poet and journalist) described it very well for us: “smell and taste form a single sense, of which the mouth is the laboratory, and the nose is the chimney; or, to speak more exactly, of which one serves for the tasting of actual bodies and the other or the savouring of their gases.” It denotes therefore that when we eat, as we breathe naturally, retro nasal olfaction brings more information to the brain on the qualities of the food. This basically means that when we eat, we help to interpret what we eat and define our enjoyment of the food that we process in our mouth; but more about later.

This said, we can appreciate food because we have an understanding of it from our cultural heritage as well as our personal history; all of it is stored in our memory which helps to interpret our sense of smell. We retrieve information, learned up to when we are eight years old, from the space in the brain that is situated just next to the nexus where interpretation of the smell is based.

The Concrete Application

Smells are detected in the nasal cavity by specifics receptors cells of the olfactory epithelium (see figure 118). These are called olfactory receptor neurones. They are continuously replaced every four to eight weeks by new cells throughout life.

Air comes through the nasal cavities and passes firstly by the somatosensory system which recognises temperature and pain. Then it comes into contact with the olfactory epithelium. There, the odorous molecules dissolve into the mucus that has been secreted by the olfactory epithelium. This mucus is water based with dissolved mucopolysaccharides, variety of proteins including antibodies, enzymes and odorant binding proteins, diverse salts. Antibodies are necessary as the olfactory epithelium connect straight to the brain. This mucus is changed every ten minutes. It is in permanent contact to the olfactory receptor cells via cilia (eight to twenty per cell). Odours are detected through these cilia and the olfactory receptor cells communicate their findings to the olfactory nerve which relay the information to the main olfactory bulb. The olfactory receptors are very complex and specialised they recognise a wide variety of smells; they are encoded by as many as one thousand genes. They are members of the family called 7 transmembrane domain G-protein coupled receptors. The fact to be noted is the divergence of in sequence of the 3rd, 4th, and 5th transmembrane domains. This would account for the fact that so many different odours can be discerned. This helps as well to detect nuances.

Human olfactory cavity

To put things into perspective, compared to other mammals we are not exceptional as to what we can smell. Dogs are well-known trackers, and this is why: they have, for some, seventeen times the surface of the olfactory epithelium but more importantly one hundred times more receptors per area. However, we have established a better processing function in the brain and we make it up by this processing function. The floral world has a lot of scents associated with it and bees can detect it, in good conditions, from as far as a kilometre away.

The nervous signal once in the olfactory bulb is then transmitted for analysis and assimilation to other parts of the brain. An exchange occurs between these different parts and the signal processed through the parts of the limbic system (concerned with motivation, emotion, and certain memories), the septal nuclei and amygdala (known as the pleasure centres), the hypocampus (concerned with motivational memory and the association of certain stimuli with food), communication is sent for analysis to the thalamus in the frontal cortex for recognition. The olfactory cells are the only nervous cells which are replaced through life, every four weeks approximately.

There exist different theories to explain the actions and interactions happening while smelling. We understand the cellular construction and what happens in the olfactory epithelium. Afterwards it is difficult to say for certain that a precise path is reached for a specific olfactory information. Some explain that the chemical compounds are selected and that the brain will discern good or bad pattern and recognise smell for what they are by memory, association, or assimilation. Another function of smell is of warning, we recognise difficult situation by our sense of smell, especially fire and the smell associated to it.

Anyway, the subject of this post is for you to understand the process of the taste, not to become a specialist neurosurgeon!

Another aspect obviously of smell is the complexity of the nature of odours, some are quite simple, some are not so. The nature of some compounds is by essence volatile and would be easily detected, but for our normal reactions to them. However, we have the ability to detect odours that we do not at first, if we are educated and exposed to them repeatedly. On the other hand, when we are exposed to the same odours repeatedly, we tend to ignore them and treat them as irrelevant, we dim the importance of these, even when it is our own body odour. In the same manner we treat the odour associated with home, we respect it in the sense that it means comfort zone, which could mean, and this is well documented and known, that we could have attenuated ourselves to an unpleasant odour. Talking about disagreeable smell, most of them would be associated with bad memories, like ether is associated to hospital or clinical treatment, like injection.

In a restaurant, where smell is expected to be neutral, there is usually no dimming action taken by the owners; this is supposed to be handled by the air conditioning. The cheese trolley, when there is one, most of the time is left to a corner or a side of the room where it will not interfere with customers, as this should be. Of course, and this could be a very costly option, if you want to be known for your cheese offering, you will need to create a very special place like it was done for cigars in the old days. Another expensive idea would be to use aromatherapist scents to create a relatively happy feel to the place.

In a shop specialising in cheese you would expect the smell to be of the product that you will buy. However, this has to be controlled in the way that people can recognise and appreciate one smell, preferably that you would mean that it is not overpowering and let the customers recognise individual products more than just a compound smell.

As we have seen earlier odour recognition is developed from the beginning and this has the harmful effect to mean that the more we age the more we lose it. Hyposmia is a diminished ability and anosmia is total inability to smell.

Appreciation and Acceptance

There are different smells, and there are different people. This means that some people will have the ability to discern some very complex scents. They are usually analytical of character, and for a good reason as smell is a very organically sensitive sense, really emotional. We will look into the process of explanation and qualitive description in a different post.

And remember, give life to your taste buds, and above all, enjoy real cheese.