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SUMMARY Meat and water slurries of both leg and breast muscle from heavy hens were cooked in a nitrogen atmosphere. Some of the chemical components in the volatile fraction were identified by solubility classification, derivative preparation, and/or functional group analysis in combination with gas chromatography and/or qualitative chemical analyses and odor evaluation. Twenty‐nine compounds in the volatiles from leg muscle and 25 compounds from breast muscle were identified by the functional‐group trapping technique followed by gas chromatography of the effluent fractions. Qualitative chemical tests revealed 19 major classes of compounds and a few specific compounds. Removal of sulfur compounds resulted in an almost complete loss of “meaty odor” in both dark and light meat. Removal of the carbonyls from the volatile fraction resulted in a loss of “chickeny‐flavor” and intensification of the “meaty or beef‐like odor.”

Among the chemical changes that accompany the cooking of fresh beef are color changes which reflect alterations in the state of the muscle pigment myoglobin as it is affected by heat. The pigments of cooked fresh meat are of importance both because color is universally used as a guide to the degree of doneness and because heme compounds have been implicated as catalysts for certain undesirable reactions in cooked meat (8).Beef cooked to an internal temperature of 60" C. or less is considered rare and has a bright red interior; beef cooked to an internal temperature of 60" C.-70" C. is considered medium done and has a pink interior; beef cooked to an internal temperature of 70" C.-80" C. or higher is considered well done and is grey-brown throughout (1,4,6). During the process of cooking meat to a certain internal temperature, the surface naturally receives the greatest amount of heat for the longest period of time while the interior receives the least heat for the shortest time, with the result that the state of the pigment as it is altered by heat would be expected to vary continuously from the exterior to the interior. Cooking conditions, too, may further affect the apparent degree of doneness. Cover, Bannister, and Kehlenbrink (Z), reported that braised steaks cooked over boiling water to an internal temperature of 85" C. were underdone and the meat still pink.The pink pigments occurring in cooked beef are the subject of the present investigation.On the basis of reflectance spectra, Tappel (71, concluded that the pink pigments lying adjacent to the brown pigments in underdone cooked beef consist of undenatured osymyoglobin. The insoluble .brown pigments of cooked meat have been recognized as denatured globin ferric hemichromogen (9). If the pink pigments found in cooked beef do consist of undenatured oxymyoglobin, then it should be possible to extract them with water. In the present paper, the spectral and ultracentrifugal characteristics of the pigments extracted from cooked beef have been examined, and the results have been found to substantiate the findings of Tappel (7). Further work has also been done to determine the effect of heat upon the denaturation of myoglobin in meat. The water extractability of the pigments in the cooked samples was used as a measure of the degree of pigment denaturation. EXPERIMENTALCooking. For obtaining the pink cooked pigments, flank steak which was purchased at a local supermarket and then finely ground was packed into a shallow pyrex

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