Let’s say you bought some steaks or a roast at the grocery store, brought it home and stuck it in the fridge. (Hopefully, stored on a plate on the bottom shelf.) You don’t get around to fixing it (that’s Texan for preparing it) for supper for a day or two. You take it out of the fridge and it has a brownish color. Maybe a few brown spots or maybe the whole thing is just a little browner than it was when you bought it. Has it gone bad? Should you throw it out? It wasn’t cheap, so you hate to throw it out. What to do?
Check the use-by date. Smell it. Does it smell bad? If it doesn’t smell bad and if you haven’t passed the use-by date, it’s probably ok.
The meat will slowly take up oxygen from the air and turn red. In the meat business, we refer to the time it takes go from purple to red as ‘bloom time’. Most of the meat you buy in the store has been packaged so that the oxygen in the air is available to combine with the myoglobin in the meat. That’s why it is a pretty red color in the store.