One can of Oregon Fruit puree should do it. Honestly, I don't recall what volume the cans are...I want to say 42 oz. You can get them at your lhbs. And yes, your yeast will eat it up, so watch your airlock. Depending on headspace, you may want to put a blow-off tube in. Looking at the OP again, a full can for strawberry and may 1/2 to 3/4 for the raspberry.