MARIANNE: Yes the participants sit in the sauna for 15-20 minutes, but there are also other ways to induce sweating; it depends on what the customer is looking for. There are different types of sweating resulting from different metabolic situations! For example we can induce sweating passively via the sauna or hot room, as well as actively over a period of time on a cross trainer or exercise bike. We once carried out a study in which the customer wanted to investigate the efficacy of their product against stress related sweating.
A stress test! How do you go about that?
MARIANNE: We had a psychologist come in and interview our subjects with emotive questions. This worked really well!
I always wondered why we sweat when we're stressed; perhaps there is an evolutionary link between survival and smell! Apropos malodor, what about the smelly aspect of sweat, how do you measure body odor?
MARIANNE: Our standard is the axilla deodorant test. This is performed by our odor judges, who also go by the unofficial term of 'Sniffers'; they perform 'sniff tests' (or odor intensity evaluation) by smelling the subject's armpit and rating the intensity of the odor. We have 2 approaches to the odor rating: an analogue scale which is a bit easier for the judges to use, they just judge if in comparison to the untreated area – or, alternatively, we use an ordinal scale of 0-5 to categorize the odor intensity in one step, which requires a little more training. However, if you achieve an improvement with your deodorant on the ordinal scale, you can be sure that the consumer in the real world will notice the affect.
FREDERIKE: Yes, and it is important to mention that initially, the noses of the odor judges are tested with isovaleric acid, which is one of the odor causing components of sweat, in order to identify any judge who on the day would not be able to rate the intensity of this component, perhaps due to a cold, and thus would have to be replaced. The judges then smell both armpits before deodorant application and rate this, then the subject applies the test product to one armpit and the judges then perform a second sniff test at each armpit . In this way we can compare treated with untreated before and after product application to assess deodorant efficacy.
So who are these talented individuals who make up our panel of odor judges, can anyone become one?
MARIANNE: Well it's not like anyone can say 'OK today I want to be an odor judge'. Not everyone has the required ability in detecting the intensity of odors.
FREDERIKE: And even if they do, they must undergo regular training. They have to be trained according to a recognized standard. For instance our odor judges are trained once a year and again directly before every study to ensure their noses are calibrated, so to speak.
Our odor judges are trained by Olfasense, which is a company specializing odor measurement and are based in Kiel. An Olfasense trainer will visit us with an Olfactometer and train our judges on site.
And how is this 'odor judge training' performed?
MARIANNE: there are some standard substances, which are close to the those found in actual sweat; and the judges have to smell these and then rate the intensity of the odor according to what they perceive, and then this is compared to what the instrument (Olfactometer) measures. This process is repeated until they are in-line with each other; at the end of the training the judge's rating will match the instrumental measurement. Initially, the sensitivity of the judge's nose is assessed to see if they are suitable for this particular study, i.e. that their sense of smell is sensitive enough in order for them to be able to detect these substances at different intensities.