What book is this?? PLEASE HELP!?

I remember reading a book in elementary school about this woman and young boy who were stranded in the middle of the ocean either from a plane crash or from their ship sinking... I can't remember! Anyways there was one part where they find a tomato and the woman tries to get the boy to eat it but he said it was against his religion... I wanna say he was muslim... Maybe. PLEASE HELP!!!!!