Another Edison invention came about as a result of the laboratory's work with glass vacuum tubes in the development of the incandescent light bulb. In 1881, Edison filed for a patent for a method to preserve fruits, vegetables or other organic substances in a glass vessel. The vessel was filled with the items to be preserved, and then all the air was sucked from it with an air pump. The vessel tube was sealed with another piece of glass.
Another food-related invention, wax paper, is often attributed to Edison, but it was invented in France in 1851 when Edison was just a child. Edison did use wax paper in his sound recording work, which might be where the story originated.