As far as I can tell, Turin is the only one still pursuing this theory, and he hasn't made a lot of headway. About five years ago he was trying to prove his theory by producing molecules with heavy hydrogen, which would smell different by his theory and the same under conventional theory, and the results were inconclusive. He seems to have moved on to other areas.
His theory has a fascinating way of explaining what it means for novel smells to be judged similar, but nobody can find a mechanism that would allow it to work. That's not proof that it doesn't work that way, but the conventional theory is proving very productive in research, and his hasn't.
Re:How to Smell (2018)
by kieckerjan on Tuesday October 01, 2019 @08:24AM
(#21124517)
Thanks for the update! Would love to see some pointers.
Two basic observations about smell combine to make it hard to explain. Firstly, it is more or less instantaneous. Secondly, we can discern new smells, even smells that did not exist before. Now, we know biological receptors that are very fast (tastebuds, say) but they can typically detect only a few, fixed sensations. And we know biological systems that can learn new stuff but they are relatively slow: the immune system, for instance, takes hours to days to learn to recognize something new.
Here is "smell professor" Luca Turin explaining his theory: https://www.youtube.com/watch?v=yzOcvINn8Iw