Keep Bananas Fresh Longer by Separating Them and Wrapping the Stems in Plastic Wrap

Bananas will brown sooner in the summertime than in the winter, and for a good reason. Heat hastens the ripening process. That is why bananas are shipped when they're green, at a temperature of 58 degrees Fahrenheit, so they do not ripen quickly. Under normal circumstances, yellow bananas will quickly brown, inside and out, giving them perhaps a two-day range of freshness. There is a way, though, to keep bananas fresh for a couple days longer


Source: http://www.ehow.com/how_4456966_keep-bananas-fresh-longer.html