A strange piece of fruit that appears to be an apple. No preservatives and no additional food coloring added. This fruit has been infected with the radiation of the wasteland, and passes on a few rads to anyone that consumes it.
In Fallout 2, fruit can be used to make super stimpaks. Myron can be recruited into the party, and with 76% or more Science skill, the Chosen One can ask Myron to make super stimpaks: the recipe is fruit + Nuka-Cola + stimpak. Each one takes a little time to make.