I'm not sure you could definitively measure such a response to conclusively prove anything from a scientific perspective. I'm curious if knowing or not knowing that would be beneficial. Focus on what happened and pour everything into replicating the results. If you can make that happen, your taste will be improved.
This might help understand the process and zinc was the only substance that withstood double blind trials still had mixed and inconclusive results.
http://web.mnstate.edu/provost/Biol...inical%20Problem%20of%20Taste%20Loss.pdf