Why is dark meat dark and breast meat white in a chicken?
White meat is white because of lack of exercise. Dark meat, which is actually “red muscle,” is used for sustained activity–chiefly walking, in the case of a chicken. The dark color comes from a chemical compound in the muscle called myoglobin, which plays a key role in oxygen transport. White muscle, in contrast, is suitable only for short, ineffectual bursts of activity such as, for chickens, flying. That’s why the chicken’s leg meat and thigh meat are dark and its breast meat (which makes up the primary flight muscles) is white. Other birds more capable in the flight department, such as ducks and geese, have red muscle (and dark meat) throughout.
