Mary Engle Pennington was a bacteriological chemist who revolutionized methods of storing and transporting perishable foods . Denied a B.S. degree in 1895 because she was a woman, Pennington went on to head the U.S. Department of Agriculture's food research lab. As persuasive as she was resourceful, Pennington was able to convince farmers, manufacturers, and vendors to adopt her techniques. She developed methods of slaughtering poultry that kept them fresh longer, discovered ways to keep milk products from spoiling, and determined how best to freeze fruits and vegetables. Pennington was the first female member of the American Society of Refrigerating Engineers. She eventually went into business for herself as a consultant and investigator in the area of perishable foods.

Pennington was born October 8, 1872, in Nashville, Tennessee. She was the first of two daughters born to Henry and Sarah B. Molony Pennington. Pennington spent most of her early life...