Oxygen and sodium nitrate both turn myoglobin red, but nitrate attaches with a more stable bond and so the color lasts longer. Although for several hundred years, nitrites and nitrates have been used to preserve the color of meat, more recent evidence shows that these chemicals also inhibit the growth of bacteria, including the bacteria that cause the deadly disease, botulism.
Give Now ». Noon Edition. Home Archives About Contact. Media Player Error Update your browser or Flash plugin. What Are Nitrites? However once a calf is weaned and begins to eat grass, its flesh begins to darken. Intact males such as breeding bulls have muscle that contains more myoglobin than females heifers or steers castrated males at a comparable age.
Generally, beef and lamb have more myoglobin in their muscles than pork, veal, fish, and poultry. Game animals have muscles that are darker than those of domestic animals, in part due to the higher level of physical activity, and therefore they also have higher myoglobin. Meat should be allowed to bloom completely the bloom usually reaches its peak about three or four days after cutting or be wrapped on a meat tray with a permeable wrapping film as in supermarket meat displays.
If portioned steaks are to be vacuum packed, doing so immediately after cutting but before the bloom has started will allow the steaks to bloom naturally when removed from the vacuum packaging. Certain phases of meat processing can also trigger discolouration. Oxidation browning metmyoglobin can develop more rapidly than normal if something occurs to restrict the flow of oxygen once the bloom has started but has not been allowed to run its full course.
The two most common examples are:. There are two other types of discolouration that commonly occur with beef and pig meat. Although the cause of both types occurs before death ante mortem , the actual change does not show up until after death post mortem. PSE pale, soft, and exudative occurs mainly in pigs and in some cases has been found to be genetic.
PSE is brought about by a sudden increase of lactic acid due to the depletion of glycogen before slaughter, which in turn causes a rapid decline in the pH post slaughter. The visible signs of PSE can be detected by the trained eye in the pork loin primal, where the flesh appears much paler than normal. The muscle meat is softer and may be very sloppy and wet to the touch and leaking meat juices, a result of a high proportion of free water in the tissues.
Although product with PSE is safe to eat, its shelf life is limited and it may become tougher sooner if overcooked. DFD dark, firm, and dry occurs mainly in beef carcasses but sometimes in lamb and turkey. In the meat industry, these carcasses are referred to as dark cutters. Instead, there may be an increase of stress hormones, such as adrenaline , released into the bloodstream. Consequently, glycogen muscle sugar is depleted before slaughter due to stresses.
This decreases the lactic acid, which in turn affects the pH, causing it to not drop fast enough after slaughter. Therefore, the muscle meat, typically in the hip area of the carcass, may become very dry and dark. Even after the carcass is aged and the meat has been processed and displayed, the dark appearance remains and bloom will not occur.
In addition, the meat may also feel sticky to the touch, which limits shelf life. Even though meats arriving at their final destination point of sale have usually been approved and inspected, the product still requires further checks prior to sale and eating in case abnormal meat inconsistencies were missed in the inspection process.
Meat from the breast and wing muscles of birds that fly in short bursts, such as chickens and turkeys. Meat from highly used muscles in poultry.
In birds that fly long distances, this is all of the muscles, while for those who fly in short bursts only, such as chickens and turkeys, this is found only in the legs. Medium-sized birds, sized between the larger pheasants and the smaller quails.
This color change alone does not mean the product is spoiled. Related Information Title. URL Name. Related Articles What determines the color of meat?
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