how ground meat turns red

Discussion in 'Food & Cooking' started by siduri, Jan 14, 2012.

  1. siduri

    siduri

    Messages:
    3,599
    Likes Received:
    46
    Exp:
    At home cook
    I bought some beef at the butcher today and had him grind it (i watched, he cut it and put it in the grinder, and then wrapped it up, nothing more).  I opened it and it was bright red outside and very dark red inside.  The dark red is what i expected, since it got exposed to air, but why is the OUTSIDE bright red?  I thought the supermarkets put something on meat to keep it red, but he clearly didn't. 

    The meat was wonderful - it's a very good butcher - but i was just curious about the color.  I'd have expected the inside to be redder than the outside that's exposed to air.  (It was wrapped in waxed butcher paper)
     
  2. phatch

    phatch Moderator Staff Member

    Messages:
    8,546
    Likes Received:
    510
    Exp:
    I Just Like Food
    Your suppositions are backwards. Fresh beef is dark red, heading towards purple. Beef that's been exposed to oxygen turns bright red on the surface.

    The plastic wrap used at most butchers in the US is not air tight but allows the meat surface to bloom red from the various globins still in the meat. US consumers often mistake that to mean fresh when darker is fresher.

    In the case of your ground beef, the interior meat is protected from the air more, keeping it the darker color. While the meat on the exterior had time and more air exposure to make it brighter.
     
  3. siduri

    siduri

    Messages:
    3,599
    Likes Received:
    46
    Exp:
    At home cook
    Ah, of course, Phatch.  Makes sense.  I hadn;t thought of the fact that oxygen is what turns our blood from blue to red.  I thought they colored the meat in supermarkets in the states so people would think it was fresh. 

    thanks. 

    This guy's meat tastes so incredibly good, i would have hated to find out he was doctoring it up somehow!  There are about 6 butchers in this market in Rome, and they all have one or two people waiting.  This one had the system with the numbers and there were 20 in front of me!
     
  4. blueicus

    blueicus

    Messages:
    928
    Likes Received:
    13
    Exp:
    Owner/Operator
    And the reason overexposed meat turns brown is due to the the change of the myoglobin to metmyoglobin after extended periods of oxidation.  So typically meat turns from a dark red/purple to bright red to brown as exposure to oxygen increases.