Common advice is that you must eat fresh fruits and vegetables. I've long wondered why fresh, other than they seem to taste better and look better. Do they offer more nutrients? Belgian scientists' 2007 research shows that nutritional value varies with time of storage, but not necessarily always going down. See Figures 2 and 3 of the article for six kinds of fruits or vegetables. The only one that almost constantly loses antioxidants may be bananas. The take-home message is that you don't have to eat fresh, as long as they're not rotten.