One bored lunch, I was lazily reading through the chemical properties of benzyl ether and diphenyl ether on Sigma Aldrich’s website, and for the first time I noticed a line called “organoleptic: almond; chocolate; spicy; fruity; sweet” and “organoleptic: geranium; green” for the two chemicals.
After consulting Google, the most revered of reference resources, I found that organoleptic means “acting on or involving the use of the sense organs”, and the etymology comes from the greek “organon” (organ) and “leptikos” (take). It came into common usage in the mid 19th century. I was intrigued, so I investigated further.
Many readers may be familiar with one of the earlier organoleptic tests, the Scoville Scale, which was developed in 1912 and is used to determine how spicy chilli peppers are. In this test, a pepper is dried, the mass is measured, and then alcohol is used to extract the capsaicin, which is the compound responsible for spiciness. The extraction is then diluted in sugar water and given to a panel of five taste testers (those with acute and trained organoleptic skill), and they try more and more concentrated solutions until three of the five can taste a hint of spice. The more dilute the solution, the spicier the pepper.
Organoleptic testing increased in over the years popularity, and in the 1950s scholarly articles, such as Organoleptic Panel Testing as a Research Tool (Cartwright et al. 1952) in the journal Analytical Chemistry examined the best way to conduct such tests. The authors suggest that depending on the training and experience of the testers, at least three but up to fifteen members should be used on a panel to get reasonable consensus on the quality of the food in question. This selection process is rigorous—potential members would commonly be given three samples of food (two of which were identical) to test how consistent they were in their judgement. Furthermore, they need to be able to reproducibly determine which samples are of higher quality from a set based on a predetermined rating (possibly that of an earlier organoleptic panel!). Because the palate undergoes sensory deprivation after prolonged exposure, half hour breaks are taken after about eight tastings of bland food, or three to four tastings of spicier foods.
The major question that remains is: are there other analytical tests that are more reliable than the opinions of trained human taste testers? There is an anecdote in Organoleptic Panel Testing as a Research Tool about how consumers were complaining that their cigarettes had a most “objectionable odor”. Experts believed that a particular insecticide was the cause, so an organoleptic panel was convened. After tasting various dilutions of the pure insecticide and samples from the cigarette packaging, they determined that the predicted insecticide was indeed the cause, and was present in the cardboard container at a concentration of one-tenth of a pound of insecticide per ton of packaging material (0.005% contaminant by mass). The authors concluded that there was no other way of identifying the contaminant in question. Perhaps modern tools that have gained acceptance since the 1950s could identify this compound (mass spectrometry and nuclear magnetic resonance) assuming the spectral signal of the contaminant is known and that signal wouldn’t be washed out by the major components of the packaging material. But perhaps for some compounds, the human tongue is a superior analytical tool in itself. (For the curious, current testing methods are a mixture of Gas Chromatography/Mass Spectrometry, High Pressure Liquid Chromatography/fluorescence, and organoleptic panels).
It turns out that in the food industry, those who engage in organoleptic activities are gainfully employed. In fact, the federal government and several state governments mandate that in case of an environmental disaster, people who are expertly trained to taste for crude oil must test seafood before it is put on the market. In 2002, the National Oceanic and Atmospheric Administration released a document, Managing Seafood Safety after an Oil Spill, detailing how to test for food safety. In addition to the normal chemical techniques one would expect, the human nose and tongue plays a large part. Before food can go to market, the experts smell the raw food, then smell the cooked food, and finally taste the cooked food to detect if there is any taint from oil. In fact, because it is not known which chemicals cause humans to perceive an taint of “off-taste” or “off-smell”, organoleptic panels are the only way of identifying a taint!
Now that I know a career in taste testing could await me me should I become disenchanted with research, I started looking into job opportunities in this under-appreciated field. According to Managing Seafood Safety after an Oil Spill, I would have to attend “harmonization workshops” (I kid you not) to ensure that I adhere to universal sensory criteria and evaluation practices so I could start in the ranks as a trained assessor, only capable of specific tasks. After gaining more tasting experience, I could become an expert assessor, and make it a full time career. Finally, when I get bored of simply tasting the food, I could become a trained facilitator to coordinate proper preparation of the food for the taste testers, ensuring controlled testing conditions, and statistically rigorous analysis of the panel’s findings.