FoodNet

Experimental cookery

1932

Page 167

Presented as published in 1932. Historical recipes may not meet modern food-safety standards. Cook from the modern interpretation, not the original instructions.
The hemoglobin of the red corpuscles is the pigment giving blood its purplish-red color. The combination of hemoglobin with oxygen forms oxyhemoglobin, which is a bright scarlet. Meat is a darker bluish-red when first cut, but if the cut surface remains exposed to the air it becomes a brighter red color. When hemoglobin and oxyhemoglobin are acted upon by enzymes, acids, alkalies, or heat, various decomposition products are formed. Hematin is one of the decomposition products formed by heat. The coagulating temperature of oxyhemoglobin is around 64°C. Thus when meat is cooked to temperatures higher than this the production of hematin brings about the brown or gray color of well-done meats. Dilute acids or alkalies may also produce hematin from hemoglobin. Muscle pigments. The red pigments of muscles resemble the hemoglobin of the blood. These pigments are sometimes designated as chromatin sub- stances. Whipple and Robscheit-Robbins call them muscle hemoglobin, and they have reported that the properties of the muscle hemoglobin are prac- tically the same as or identical with those of blood hemoglobin. Whipple has found the content of muscle hemoglobin higher in active hunting dogs than in inactive house dogs. He states that under different conditions the muscles may contain from 10 to 80 grams of muscle hemoglobin for each 100 grams of blood hemoglobin. Skeletal muscles vary in color in the same animal and in different species. Sometimes the pigmentation varies in the same species but with different types or breeds. Dairy cattle have darker-colored muscles than the beef types. The color of the muscle of the young animal is often lighter than that of the same muscle from an older animal. Veal is lighter in color 210 MEAT than beef, and the leg muscles of broilers are lighter than those of mature fowls. Different muscles of the rabbit vary in color from a very light pink to a deep red. The different muscles of pork also vary in color. In general the muscles of the lower animals are not pigmented, with the exception of the heart muscle. The muscles of fish are white or light in color, but the muscles of nearly all mammals are red. Needham states that "red pig- mentation seems to occur in muscles from which the most persistent and prolonged activity is required." Earlier investigators have also suggested that in general pigmentation occurs in muscles used most frequently. Ejfect of ripening upon meat pigments. Meat that has been ripened 40 to 60 days is usually a deeper gray in color, when cooked, than unripened meat from the same animal, provided the cooking conditions are the same. The darker color may be due to the action of enzymes and acid upon the hemoglobin, so that more hemoglobin is broken down to produce hematin at lower cooking temperatures, or it may be due to other factors. Non-nitrogenous extractives. Lactic acid is always present in muscle tissue. The amount is small while the muscle is at rest and increases during and after exercise. After death the percentage of lactic acid in the muscle increases.