Ground meat colors more fresh outside and darker inside? (burger, buy, Walmart)

[snowmountains]

In supermarkets the ground meat always have more fresh-looking reddish color in the outer layer, but the inside looks darker and less fresh. I used to think it's the sellers disguising bad meat underneath, but it doesn't appear so after seeing it everywhere. Why?

[Hedgehog_Mom]

The bright red color is from the meat being exposed to the air. If you break it open and let the darker parts set out for a couple of minutes, they will turn bright red too.

[TabulaRasa]

Yep. Exposure to oxygen causes the red color.

[snowmountains]

I see. Thanks.

[mainebrokerman]

its called oxidation,,,no different than our own blood that may be purple,(ish) then hits oxygen and turns bright red -it blooms

the outside of the burger has "bloomed" turned red by oxygen, while the inside has not been mixed with oxygen

with no oxygen, it reverts back to its original color - id be more concerned if it wasn't dark in the middle

the leaner the burger is, the quicker the middle changes color, also if it is wrapped tight/squished in the package,



again, no different than if you bought a whole rib eye and cut it yourself, when you first slice it is purplish, then it blooms to bright cherry red (when oxygen hits it)



and buy burger only at places that grind it fresh on site- Walmart does not grind or cut anything fresh. it is shipped in and taken out of a box

[snowmountains]

Thanks for the explanation!