"In 40 years, in eight countries, if I think of major product recalls and food poisoning outbreaks, I can't think of [one] that was driven by a shelf-life issue," Ruff says.
Canned food, in particular, can stay safe for a really long time. In 1974, scientists at the National Food Processors Association in Washington, D.C., got their hands on several old cans of food.
Janet Dudek, now semi-retired and living in Vienna, Va., was among the scientists who analyzed this old food. Her assignment was a can of corn, vintage 1934, that was found in someone's basement in California.
When they opened the can, Dudek says, the contents looked and smelled pretty much like ordinary canned corn. Analysis showed that it had most of the usual complement of nutrients although there were lower levels of a few, such as vitamin C.
Results were similar for century-old canned oysters, tomatoes and red peppers in cans recovered from a sunken steamboat, buried in river silt near Omaha, Neb.
Dudek says, as far as she knows, nobody actually tasted this food. That just wasn't done, she says. But they probably could have. "It would have been safe to eat if the can itself maintained its integrity," she says.