A friend writes:
Why do people continue to think that cotton candy is a flavor? It's spun sugar with food coloring. It tastes like... sugar.
Now I'm curious.
Ignoring for a moment any possible contribution of the food coloring, are there chemical changes to the sugar (sucrose, I presume) during the heating process that are distinguishable by the human olfactory or taste system?
The smell of a cotton candy machine and fresh cotton candy definitely seems distinctive; I'm sure the machine itself and the increased aerosolization of the sugar in the vicinity both have something to do with that. Similarly, the increased surface area of the sugar probably changes the magnitude of our tastebuds' responses. But I wonder about the specific chemical changes involved, and whether they're detectable by most humans.
(Psychologically and/or neurologically, I'm sure there's something to be said about the whole experience of cotton candy changing our perception of how it tastes. In this case, I'm looking for the basic chemistry and biology.)