I am attempting to make a diabetic carrot cake, found on this site, for my dad. it calls for unsweetened pineapple juice concentrate. Not to sound like I don't know what I am doing, but can you clarify this ingredient for me. Is it the frozen juice concentrate from the can? Is it mixed with water to make the pineaplle juice? Or, is it unsweetened juice from a can of pineapple? Just not sure about this and would like a little help. Thanks.