White vs. Dark Meat – from the #DailyMeatLesson

By Christopher R. Raines

I try to provide a #DailyMeatLesson to the Twitter world, and that 140 character quip gets read, re-tweeted, and hopefully people learn a different little factoid about meat every day.  Per the fantastic suggestion (albeit anonymously) of a dutiful Twitter follower, I am going to (hopefully I can keep up daily) expand on the daily meat lesson with a blog post.

Today’s #DailyMeatLesson was:  Dark meat is darker than white meat due to greater fat and pigment content.  Let’s take this from the top, and bear with me…  (and for any meat scientist out there, my intent is to communicate the basics and not re-write a lecture over muscle fiber types).

Different muscles serve different functions, and to fulfill those functions, their metabolism can vary.  Based on how a muscle gets its energy, it can have one of three fiber types:  white, red and intermediate (you can think, pink).  Muscles with an abundance of white fibers (also called fast-twitch) tend to be more glycolytic — they get their energy from glycogen stores.  Muscles with an  abundance of red fibers (also called slow-twitch) tend to be more oxidative — they get their energy from oxidation processes.

Let’s take it back a few gears to this post, where I talk about the basics of meat color.  Meat color is a function of how much myoglobin is present.  And, myoglobin is an oxygen carrier in muscle tissue.  So… the red fibers are redder because they contain more pigment.  When cooked, myoglobin will turn brown.  Due to the difference in pigment concentration, cooking a whole bird will yield some meat that’s darker than some of the other meat.  There’s white meat, there’s dark meat.

But what about the fat?  Keeping in line with the the muscle function idea, what do chickens and turkeys do more of, walk or fly?  Walk.  When they fly (or at least try), quick bursts of energy are used.  When they walk around, a continued energy source (aka fat) is handy.  The greater fat content of dark meat also can lend it juiciness.

More pigment.  Some more fat.  Dark meat.

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