Good question, I was going to make a big batch of persimmon wine this year. I collected the fruit from our trees and froze about 40 lbs of Fuyu's. Then I started reading that persimmons were high in magnesium and worked well as a laxative--I read that wine made from them also retained this quality, needless to say they're still frozen...
Google persimmon wine and see what you find. Maybe as an smaller part of a beer it won't be noticeable.