From: andrew 7/12/99 11:59:02 Subject: Colour of meat post id: 13893 What makes white meat white and red meat red? Why does a cow have red meat, and pigs and humans have white meat? Why does a chicken have white meat, but an emu (another bird) have red meat? From: brad 7/12/99 13:19:21 Subject: re: Colour of meat post id: 13914 Hi Andrew, The answer is BLOOD! Pork is bled after stunning by hanging the animal upside down with their throat cut. The heart is still going, which facilitates the bleeding. This improves the quality of the meat. The same thing happens with chickens. When cattle are knocked (killed), they are hung and bled, but their hearts are stopped, so the bleeding is less efficient. cheers, brad From: michael c 7/12/99 15:35:42 Subject: re: Colour of meat post id: 13952 Not quite true Brad. Red meat is red because the muscle fibres which make up the bulk of the meat contain a high content of myoglobin and mitochondria, which are coloured red. Myoglobin, a protein similar to haemoglobin in red blood cells, acts as a store for oxygen within the muscle fibres. Mitochondria are organelles within cells which use oxygen to manufacture the compound ATP which supplies the energy for muscle contraction. The muscle fibres of white meat, by contrast, have a low content of myoglobin and mitochondria. The difference in colour between the flesh of various animals is determined by the relative proportions of these two basic muscle fibre types. The fibres in red muscle fatigue slowly, whereas the fibres in white muscle fatigue rapidly. Chickens and turkeys are always assumed to have white meat, but free-range meat from these species (especially that from the legs) is brown. This is because birds reared in the open will exercise and become fitter than poultry grown in restrictive cages. The fitter the bird, the greater the ease of muscular respiration, and hence the increased myoglobin levels in the muscle tissue, making the meat browner. Michael C J From: michael c 7/12/99 16:13:24 Subject: re: Colour of meat post id: 13964 Hi andrew, hi brad, could it be more than just the presence of the blood. Does cow muscle contain more myoglobin than pig or chicken muscle? The myoglobin stays inside the muscle tissue as a reserve of oxygen solely for the muscle activity. Bleeding the haemoglobin out will still leave the myoglobin. I am unsure, so maybe some reading will aid this. Paul This forum is un-moderated. The views and opinions expressed are those of the individual poster and not the ABC. The ABC reserves the right to remove offensive or inappropriate messages.