Pit 4 brains and Pops , this is all very true .... having been in the retail meat business for 26 years , I have had numerous customers accuse me of putting "nice fresh meat on top of old meat " ....lol ...as if I would have time to do that ....lol ... truth is the packaging film we use allows oxygen thru to the natural enzymes in the meat therefore turning the surface a nice bright red ...the enzymes use up the oxygen at the surface , therefore leaving the center brown ...due too lack of oxygen .... this is especially apparent with ground meat that is made with "fresh only meat " ( not frozen ) .... put frozen beef such as the 60 # NZ blocks of cow meat into the mix and the burger will remain a nice red color throughout the meat into the center ... makes people happy cause of the redness .... but most don't understand or see the lower quality they are purchasing .... but hey they are happy ... it's a nice red .... lol