As your question was already answered I just want to add my two cents. What people ask very often concerning guinea pigs feed is can they eat bananas or not? The article I gave will help you find out everything about it.
They might be able too but make sure first, because guinea pigs can be sick if they eat something bad
My guinea pigs like, no, love crasins! The only thing is the added sugar that is in the berries. Make sure to only give them small amounts at a time so that their system can handle it. I give mine 4 or 5 a week.