Method of Preserving Fruit
Another Edison invention came about from the laboratory's work with glass vacuum tubes while developing the incandescent light bulb. A development, we should add, that is not solely Edison's. Many others were involved in the research and labor of the light bulb production -- but Edison got the much-sought after patents.
But getting back to our story. 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.