Which Cut Is Older? (It's a Trick Question) - New York Times

Warning: The bright red color of meat may no longer be a sign of freshness.

Traditionally, shoppers have looked at the color of meat to judge its freshness, with bright red signalling newly-cut meat, and brown indicating older stock. But a new way of treating meat with carbon monoxide keeps the meat looking bright red, even when it has gone bad. Consumer advocates are complaining that this can trick consumers into buying meat that is past its prime.