First: this is obviously a trick question, we all know that Jon has the answer to any question. Which leaves us to wonder why he wont tell you what it is.
I also have very intense dislikes covering many of the same species. Years ago a plant biochemist wanted to purify the key compounds (I think a lot were terpenes) and see if she could determine which aspects caused the most intense reaction. Had these been the tastes I loved the most I would have gone along but, even to help the advancement of science, I could not agree to testing the purified essence of my least favorite tastes.