Talking Turkey

The centerpiece of most people's Thanksgiving dinner is the turkey. Turkey is, of course, a kind of meat, by which we usually mean the muscle tissue of an animal - beef from cows, pork from pigs, veal from calves, turkey from turkey, etc. Meat is, in general, a very nutritious food because it contains a lot of the proteins we need to stay strong and healthy (although it is possible to get those proteins without eating meat).

You've probably noticed that turkey (and chicken) meat comes in two colors, which we call white and dark. But we never see "white" beef, or "dark" fish. Why not? The color difference is due to a chemical called myoglobin which stores oxygen. Darker meats contain more myoglobin than whiter meats, and muscles that get more exercise have more myoglobin. Cows walk around a lot finding grass to eat, so they get plenty of exercise, and all of their meat is dark. Turkeys, on the other hand, stand around in pens just waiting to get fed, and they rarely, if ever, fly. Their legs and thighs work hard, but their breast muscles, which control their wings, don't do very much. So, their leg and thigh meat is dark, but the breast is white!