full article see: Perfumer & Flavorist, Vol. 26, Jan/Feb 2001
• Language is important in
recognizing smells. An
important part of perfumery training is to develop an odor language based
on olfactory standards. The
possession of such an odor language increases the powers of
discrimination. Start with the
Jeanne Rose Basic 7 Vocabulary
• Different people perceive
odors differently. Smell is subjective and it is easily demonstrated
that, at least in some cases, we do not all perceive the same material in
the same way. This is why education/vocabulary is the key to be able to
describe odors through a group of people,
• Perception of odors can be
distorted. Psychological pre-conditioning can distort the perception
of the odor. For example, a
fragrance chemist can be affected by seeing the structure of a molecule
before smelling a sample and a wine expert by the addition of an odorless
and tasteless red dye to a white wine or even by the bottle from which the
wine is poured.
• Can't smell a pure sample but
know it in something else. Some people may be unable to smell a
specific material when presented with a pure sample, yet will be able to
recognize its presence in a fragrance.
• Can't smell certain odors. Some
individuals are anosmic to an odor type, for example there are individuals
who cannot smell any musk materials. But
it is very common, possibly universal, that an individual will be unable
to smell one representative material of a given odor class yet will
perceive other materials of the same class very strongly (as an example to
illustrate this point and the one immediately preceding it, there is a
perfumer who can smell all musks except galaxolide, yet can easily
recognize if galaxolide is
present in a fragrance.)
• Olfactory illusion. In
some cases, a perfumer can identify by smell alone all the components of a
fragrance, even if some of these components are themselves complex
mixtures, such as essential oils. However,
in other cases, blending of ingredients can create the illusion that a
certain material or class of material is present when it is not.
In other words, it is possible to create an olfactory illusion.
In the first case, the sense of smell appears to provide us with an
extremely effective analytical device, yet the second case shows that it
can be deceived.
• People can be trained to smell
odors. People can sometimes learn to smell materials to which they
were previously anosmic. Take a sample, label it, look at it and smell it
several times daily and say the name of the sample while smelling.
Do a different odor every month or as you learn the previous one.
• Similarly molecules, different
odors. There are many examples of cases where two very similar
molecules elicit very different odors, yet a third molecule which
apparently bears little structural resemblance to either of the first two,
elicits an odor very similar to one of them.
• Function and shape matter. Sometimes
a specific chemical function seems to be crucial in producing a specific
odor, for example, the association of the ester function with pear.
In other cases, the molecular size and shape are much more
important then chemical function, for example in the case of the camphor
odor, a hydrophobic ellipsoidal shape of the correct size is all that
seems to matter. Vibration matters.
Keys of Scent fit into the
sensory locks of odor in the nasal mucosa (in
the same way that your house keys fit correctly into your house locks).
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