In my childhood, we had these kinds of root vegetables sliced and caved in on one end, and a spoonful of honey was placed on top and in the cavity. Somehow this sped up conversion to overnight, and it was a treat. I guess, similar process could be used to convert them for brewing.
Although the whole idea sounds a bit like potato for vodka. Nothing wrong with that too, but the flavor might me less than interesting in the end. Worth trying I guess. I wish I had some of those now, not unripe ones from the store.
Well, it's bad news, all those super-processed products almost always are treated with metabisulfite or something close enough, and only wine and a few other products require it to be listed on the label. It's pretty much treated as part of detergent for washing fruits. Completely unjustified as product is sterilized later in turning it into extract, but it is simpler to keep buying this historically accepted mild bleach and treating all fruits with it anyway. Maybe increases their storage time in shipping pipeline. Something I do not wish to think about in great detail, for my first lab in Finland was in a rented fruit storage bunker and I washed it and dismantled control equipment myself. Could have been WW2 nazi camp facility for what it was worth.