Marla e-mailed the Kitchen Shrink that she had accidentally put her bananas in the refrigerator in a bag of groceries and now the skins are black. She wondered if they are still good to use.
Bananas are still just fine to use if they have been refrigerated and the skins have turned color. Bananas are picked green and ripen at room temperature. Refrigerating them not only causes the skin to darken, it slows down or stops ripening. So, it is best to keep them out of the fridge until they are fully ripened. At that point refrigerating them will help keep them from becoming over ripe.