Following my last post about the banana blowing up a balloon, I decided to place the bottle on the stove (out of hands of curious little scientist). After a few days of thinking the experiment was over, with no real noticeable change, the experiment became more exciting! The balloon inflated more! On 2/9/12, it measured 6 cm in circumference.
I'll report back any new changes and the results of mashing up 3 bananas and repeating the experiment.