PHILADELPHIA (AP) -- A food industry entrepreneur and founder of one of the world's largest food companies has died in suburban Philadelphia. Keystone Foods founder Herb Lotman was 80.
Son Jeff Lotman says he died Thursday at a hospital from complications of heart failure.
Herb Lotman was a Philadelphia native. He began his career in the food industry with his family's wholesale beef business.
In the late 1960s, he and his partners pioneered cryogenics for McDonald's and developed a mass-production system for making frozen hamburgers.
Lotman built Keystone Foods over 40 years to a company generating more than $5 billion in sales annually. Keystone opened operations in more than 15 countries and was rated 45th on Forbes' list of America's largest private companies in 2010.