Put vinegar on it. Most moulds don't like vinegar and it shouldn't harm the plant. I use vinegar on my bananas too.

chamomile tea is better for mold, won't acidify anything.
did you let the pineapple top dry out for a few days?
Applying heat is good..
Plus, what I do, is make a depression in the soil and lean the pineapple top in the depression, and when roots form, THEN cover the rest of the end with soil...

You made sure there was no fruit on the top, right? I twist the top off the pineapple....

Yes, I did make sure there was no fruit on the top and I did let it dry out for a few days before I planted it. Thanks for the advice....I'd never heard of putting vinegar or cammomile on mould. Great ideas! Thanks again...I hope it pulls through!