Adding banana to wine for extra body

Hi
I've have just transferred my loganberry and black currant wine from the fermentation bucket to demijohn to ferment. It tastes like it needs more body.

I have heard that a single banana can add extra body without affecting flavor. How would I add the banana? Would I need to boil it and mash it then put my wine back in bucket to mix the banana then put back in to the demijohn to ferment?

Any other easier ways I can add my banana?

I make banana wine and add it as needed. Most boil it down,

You can also add tannins, this will help in creating a better mouthfeel.

I agree with Julie on using tannins instead. But when I have used bananas in my wines for extra body I just peeled and threw it in to the primary

When I use bananas in this manner, I slice the frozen banana skins and all, add to 1-2 quarts of water, simmer for 10-20 minutes, then depending on the wine, either add everything or more often just strain the water into the primary before pitching the yeast.