The American Meat Institute has posted a video explaining the different types of mat packaging common in supermarkets today. They focus on the packages that are filled with nitrogen, carbon dioxide and carbon monoxide which keeps the meat bright red... Something that's good for retailers because that's what consumers are used to buying, but which also keeps meat looking fresh well past spoilage.
The practice is banned in Europe, Safeway supermarkets stopped carrying meat packed with carbon dioxide in the wake of the Chinese import scares (federal law prohibits hiding the possible adulteration of food), and consumer protection groups have been advocating banning this type of packaging since 2006. But AMI wants us to understand that this type of packaging is GOOD for the consumer, because we're used to seeing red meat.
(See related news report: http://www.youtube.com/watch?v=23bASakK-MY