How does the ability to taste PROP relate to taste sensitivity?
There are at least two, and probably three, factors which determine how strong PROP will taste to you. First, you have to have the active gene for the ability to taste PROP. People who have the active gene will taste the bitterness of PROP, whereas people who have an inactive gene will not taste anything, because their taste bud cells don't have a receptor that can bind to PROP and send the message that binding has occurred to the brain.
The second factor is the number of taste buds on your tongue: the more taste buds you have on your tongue, the stronger PROP tastes to you, provided you can taste PROP at all -- the more papillae you have, the more taste buds you have; the more taste buds you have, the stronger the taste signal your brain receives, whether from PROP or from natural food.
The third factor involves attention. The more attentive you are to a stimulus, the stronger it may seem.
How does the strength of mint flavor relate to taste sensitivity?
We have been using the flavor of peppermints as a substitute of PROP in measuring taste sensitivity, because peppermint flavor is more pleasant, and measures more aspects of flavor. The response to peppermint involves not only taste (for the sweetness), but also smell, and sensitivity to trigeminal activation (= the cool feeling of mint). Most foods present some combination of these sensations, so we believe that testing with peppermints reflects general flavor sensitivity.
When we test with peppermint, we score the intensity of the "rush" of sensation people may get in the back of the throat and the nose as well as the intensity of flavor. This rush of sensation is due to the activation of the trigeminal nerve endings in the taste buds and in the nose. As a result, we find that people can be divided into four groups: a group for whom the mint is mild, and who don't get the rush; a group for whom the mint is very strong, and who do get a rush; and finally two groups for whom the peppermint is moderately strong: one group does get the rush, and the other doesn't. People who find the peppermint moderately strong but who don't get the rush are similar to the mildly sensitive tasters in many of our psychological and behavioral tests, so the general outline of the differences among taster groups given below (which refers to PROP) also applies reasonably well to the peppermint results.
How many taster types are there and in what ways do they differ?
The following table shows the different taster types and some of the characteristics we have found:
|Highly sensitive tasters||Moderately sensitive tasters||Mildly sensitive tasters|
|Very strong sensation from PROP and mint||Moderate to strong sensation from PROP and mint||Weak to undetectable sensation from PROP and mint|
|The flavor of food is important||The flavor of food is important||The flavor of food is not that important|
|Great variation in the number of foods liked; often passionate about food||Many foods liked; few foods disliked; often passionate about food||Many foods liked; few foods disliked; not passionate about food|
And what about children?
We have found that children are more sensitive than their parents ...this may explain why many children are often picky eaters! Here is a graph showing the differences between children ages 3-5 years and their parents in their mean responses to PROP. The vertical scale shows the intensity of the response - the higher the number, the more intense the response.