Why is Chicken Different from Beef?

September 10, 2009 8:13 PM

Why is chicken meat so much different from beef?

To narrow that very broad question, one thing I've always wondered is why beef (like steak, not hamburger meat) will bleed if it's not cooked enough, but chicken doesn't do the same thing. Why is that? What's different about the two meats?

I asked a friend who is a food science major, and she had no clue either, and said she's always wondered why intact beef muscle sterile, but not chicken. So why are chickens so much different from cows?

posted by DMan to pets & animals (18 comments total)

Raw chicken "bleeds". It just happens that the 'blood' is a pale pink, so it isn't quite as noticeable as the red of beef. If you undercook a chicken breast and cut it open, the juice that comes out will be pale pink.

As to why chicken is "white" when cooked and beef is ...grey? when overcooked, I don't know.
posted by LOLAttorney2009 at 8:18 PM on September 10

I would imagine it has something to do with the fact that cows are mammals and chickens are 'birds' (aves).
posted by iamkimiam at 8:20 PM on September 10

1. It does bleed, just not as much. My hubby , Ribman, is an expert when it comes to undercooking chicken, and I have seen more than enough pink juicy chicken on my plate.

2. The muscle is sterile. Nasty bugs are transferred to it during processing. And dirty surface area to tender pink meat ratio is much higher in chickens than in cows.

I'm lucky I'm still alive.
posted by SLC Mom at 8:20 PM on September 10 [2 favorites has favorites]

Not only will chicken not bleed when rare, but it doesn't seem to bleed at all.

But one is a bird, and one is a mammal, which was evidence enough for me that it
would be different. Why aren't you curious about fish as well?
posted by Palerale at 8:20 PM on September 10 [1 favorite has favorites]

Why is Beef Called a "Red" Meat?
Oxygen is delivered to muscles by the red cells in the blood. One of the proteins in meat, myoglobin, holds the oxygen in the muscle. The amount of myoglobin in animal muscles determines the color of meat. Beef is called a "red" meat because it contains more myoglobin than chicken or fish. Other "red" meats are veal, lamb, and pork.
posted by klanawa at 8:21 PM on September 10 [5 favorites has favorites]

On preview, as others have noted, the basic, first-level explanation is that cows are mammals and chickens are birds. Their most recent common ancestor lived more than 250 million years ago and was cold-blooded. In short, a whole lot of independent evolution has gone on since then. It's not surprising that there are differences in muscle tissue such as those you mention.
posted by brianogilvie at 8:23 PM on September 10

Chicken does "bleed" the amount is comparitively less because chickens are better drained of blood in slaughtering than beef, which is much larger, both in bulk and typically in cut (the slice you get at the butchers or store ain't how it's delivered to them frequently, the chicken breast is).
posted by smoke at 8:30 PM on September 10

It's not because chickens are birds. Ostriches are birds, but their meat looks and tastes a fair amount like beef. klanawa's got it, it's because of the amount of myoglobin in the muscles.
posted by fings at 8:38 PM on September 10

Intact chicken muscle is sterile -- until it gets splattered with shit-laden water at the slaughterhouse. It comes down to handling practise in the two branches of the meat industry.

Your food scientist friend seems very uninformed about where food comes from.
posted by i_am_joe's_spleen at 9:32 PM on September 10 [1 favorite has favorites]

I had always heard that chicken meat needed to be cooked all the way through because it was less dense than beef, and bacteria could migrate to the inside of the meet more easily, while bacteria on a denser steak couldn't penetrate far, so only the outside needs to be fully cooked.
posted by JiBB at 9:53 PM on September 10

I think this is an interesting question that can be dismissed fairly easily. My take is that "meat" can be broadly considered the fleshy portion of any animal, so fish, whale, octopi, lobster, and what have you all have quite different types of meat. Even mammalian meat can vary pretty widely although none that I can think of -- even, say, pork -- is as different as poultry. At the most basic anatomical level it is all a combination of muscle and fat, so has a common function, but obviously with some functional differences. For instance, birds must necessarily be lighter in order to fly. But on the other hand, bats.

Long way to say "I don't know."
posted by dhartung at 11:40 PM on September 10

Red meat is made up of slow-twitch muscles that are used for standing and walking, and need a consistent supply of energy. More oxygen = more energy, therefore more myoglobin. Myoglobin is dark red; the more myoglobin, the redder the meat will be.

White meat is made up of fast-twitch muscles used for fast burts of energy. They get energy from glycogen stored in muscles.

The specific function of myoglobin is to carry oxygen to muscle cells. It is carried in the bloodstream along with hemeglobin to the lungs to get oxygenated, then back to the muscles.

Red meat appears more 'bloody' because the muscle tissue is more highly vascularized, in order to transport all that myoglobin to the muscle cells.

Glycogen is synthesized within muscular cells and stored there, not used by other cells. So less vascularization is required, less blood, still some pink.

You will notice in chickens, for example, that the white meat is found in the breast, where the majority of muscles for flying are located. Chickens don't fly much, but they do walk around a lot, which is why their legs and thighs have darker meat.
posted by Seppaku at 12:18 AM on September 11 [9 favorites has favorites]

Because chickens are dinosaurs and beef are mammals. It may not be the best answer, but it is way cool to think you are eating a dinosaur.
posted by fifilaru at 12:48 AM on September 11 [1 favorite has favorites]

"As to why chicken is "white" when cooked and beef is ...grey? when overcooked, I don't know."

White it is cooked, the proteins in white meat just coagulate. There are a lot of proteins in muscle cells to begin with and when heated, those proteins stick to each other in a dense mass rather than being hydrated as in their natural state. When you heat a protein, it becomes denatured. Instead of a 'glob' you get a long linear chain that randomly interacts with itself. Upon cooling, the proteins stick to each other willy-nilly, giving you the denser texture of cooked meat.

Likewise, the proteins in red meat coagulate, but there is a lot of myoglobin in there. Myoglobin contains a multiring prosthetic heme group that is carefully positioned to coordinate the iron atom which binds oxygen and gives myoglobin its function. When you heat the beef to a certain temperature (140 F), the myoglobin becomes denatured, the heme group gets all out of whack, and the iron atom loses an electron, going from Fe 2+ to Fe 3+. Because of the changes to the heme group (a pigment that selectively absorbs certain wavelengths while reflecting others) cooking changes the color of the meat from red to brown.
posted by Seppaku at 12:53 AM on September 11 [6 favorites has favorites]

"she's always wondered why intact beef muscle sterile, but not chicken."

IMHO, I think it's a matter of exposure.

Chickens are generally killed and butchered and packaged out in the plant.

Slaughtered beef cows are generally hung on ceiling hooks while being processed, and then transferred as half or whole sides of beef to your local supermarket or butcher, who divides the meat into different cuts. I'm betting your butcher works in an environment far less contaminated with bacteria than a chicken packing plant.

Similarly, ground beef has a higher chance of being contaminated because it is processed through a grinder.
posted by Seppaku at 1:03 AM on September 11

Slaughtered beef cows are generally hung on ceiling hooks while being processed, and then transferred as half or whole sides of beef to your local supermarket or butcher, who divides the meat into different cuts. I'm betting your butcher works in an environment far less contaminated with bacteria than a chicken packing plant.

derail...

Everything else you said was correct, but this is not true in the US anymore. Most large chain supermarkets and butchers have opted for the more cost-efficient practice of central processing. They are delivered "boxed beef" (prices here) that is cut in a central processing facility somewhere in the cow belt and the cuts are boxed and shipped by truck where they need to go. Less weight and handling and less skilled workforce, less cost. The person in the white coat that stands behind the meat counter generally has little training in anything other than how to French cut a rack of lamb or trim down chops and how to portion and package. There may be a specialty butcher in your neighborhood that still has whole sides shipeed, but that is a tiny minority of the beef consumed.
posted by kuujjuarapik at 5:04 AM on September 11

"Why aren't you curious about fish as well?"

Fish are pretty must fast-twitch muscle all the way, hence white meat.
posted by Seppaku at 1:32 PM on September 11

Not only will chicken not bleed when rare, but it doesn't seem to bleed at all.

Palerale, you've never actually seen a live or freshly slaughtered chicken, have you? A beheaded chicken will bleed quite nicely. In fact, I'm not even sure you've even handled a raw chicken breast.

Both animals, BTW, are bled dry* after slaughter, which (IIRC) makes the meat more tender, and (perhaps more importantly) empties pathways by which nasties** can infiltrate the bulk of the meat.

* "Bled dry" does not mean no blood remains in the muscles, of course.

** Technical term for pathogenic bacteria & so on.
posted by IAmBroom at 8:59 PM on September 13