Health-conscious consumers bananas are a welcome part of a convenience store’s offering. That is, until they turn brown. Which is why Del Monte developed a new plastic wrap for bananas that promises to more than double their shelf life by keeping out air and moisture. 7-Eleven has been trialling the second skin in 27 of its Dallas-area stores. If the trial is successful, the bananas-in-bags could be stocked in the majority of the chain’s 5,787 shops by early 2010.