Olive & Oil 03/12/2012

Is the nose better then the lab?

Is it right to give a prominence to sensorial analysis over analytic and chemo-physic lab tests? We asked this question to some expert Italian tasters

Ettore Franca, head of OLEA. Chemistry and sensorial analysis work on two different levels. They must be integrated and placed on the same level.

Chemistry and sensorial analysis work on two different levels, which must be integrated and placed on the same level. Chemistry operates “analyses” (ανα λίω = melt, decompose; i.e. it breaks down); it is able to resolve and measure every different component. It is not able to evaluate the result of combining two or more molecules.
Organoleptic analysis, on the other side, makes a “synthesis” (σύν θεσις = composition, i.e. it puts together); our mouth cannot resolve different molecules but gives us a judgment about their interaction. This requires very skilled tasters, humble enough to listen at the opinion of more experienced people.

Lorenzo Cerretani, panel head. Sensory analysis cannot substitute chemical tests.

Sensory analysis is a powerful tool that presents both pros and cons over chemical tests.
The main advantage of sensory analysis is the quickness and the completeness of the analysis of a food. As compared to sensory analysis, chemical analyses require expensive tools and long times.
The main disadvantage of sensory analysis is the difficulty in aligning the opinion of different tasters and different panels. At this purpose the authorities evaluate the performances of panels every year by ring tests. Unfortunately, this approach presents many drawbacks and results are not satisfactory. In other words, having different panels aligned by ring tests doesn’t assure concordant assessments of products. Finally, if two panels composed by people of a same country can give different assessments, this problem is even more extreme if panels come from different countries. I remember a case some years ago when a same oil was evaluated as virgin by a panel from an EU country, lampante according to the panel of another EU country and finally extra virgin by a panel of a third EU country. In conclusion, I think that sensorial analysis cannot substitute chemical tests, also because nowadays tests can give precious information about the raw materials and the production processes.

Giorgio Colli, professor of sensorial analysis and Onaoo taster. It is difficult to find efficient panels.

I don’t think that the chemical analysis per se is enough. Generally speaking, chemical tests find what the tester is looking for. They are very useful afterwards instead, to confirm some hypothesis. I saw many cases in which the analysis machine gave wrong results. Hence, since olive oil is a food and consequently the final consumer tastes it, I think that the organoleptic evaluation is pivotal. I think that chemical analysis should come before tasting just when all chemical parameters are ok. A very well educated mouth is not enough. We all know how difficult it is to find efficient panels.

di L. C.