First, know that home dehydrated bananas will not turn out like the store-bought ones. The commercially prepared ones are sulfured.
There are several ways to prepare your bananas. Usually they need to be treated with lemon juice or ascorbic acid (Fruit Fresh) to keep them from turning brown. This is purely aesthetic and does not affect the taste in any way.
I’ve tried several ways of treating them, but the easiest is with a pump bottle.
Get a bottle of lemon juice, any brand will do. Remove the
cap and replace it with a pump bottle sprayer. You will use the lemon spray on
all fruits to keep them from turning brown. The mist is so fine, that it will
not affect the taste at all.
Little Round Pieces: