Experimental cookery

cooking. It seems rather certain from the results of Hoagland et al., Grass- man, and others, that the increase of amino nitrogen with aging is one factor in bringing this about. The amino acids may not be able to bind as much water as the protein, so that the free water content and apparent juiciness may be increased with increase of amino nitrogen. Sometimes the juiciness seems to be related to the fat content. How great an influence the method of distribution of the fat within the fiber, the salt content of the fiber, the pH, or the development and maturity of the fiber have upon this point cannot be stated. The tissues of old animals lose their power to bind as much w^ater as tissues from younger animals. Although this may partially explain the better quality of meat from younger animals it does not explain why veal is less juicy than baby beeves. Perhaps, if the water is bound too tightly by the coagulable protein micelles, the dryness is more apparent to the tactile sense. Child and Fogarty found that approximately 1 1 per cent more fluid could be pressed from one semitendinosus muscle when heated to an in- terior temperature of 58°C. than for the other semitendinosus muscle from the same animal heated to 75°C. Noble, Halliday, and Klaas found : "When subjected to a pressure of 3,800 pounds per square inch, the ribs cooked to 61 °C. yielded more juice than those heated to 75 °C. and the round more than the corresponding ribs. The larger quantity of juice was found to be richer in solids, total nitrogen, and, in one case, also richer in coagulable nitrogen." Empey states that for uncooked meat there is a direct relationship be- tween the hydrogen-ion concentration of the muscle fiber and its capacity for holding muscle fluid, but the author knows of no work in which juiciness of cooked meat has been related to /)H. Change in color. During the heating of meat, after a temperature of about 50°C. is reached, the color gradually changes from red or pink to a lighter shade and finally, if a sufficiently high temperature is reached, be- comes brown or gray. Veal and pork are more gray, beef and lamb develop a browner shade. This color change has been discussed in connection with meat pigments, the oxyhemoglobin being broken down by heat to the brown hematin. The degree of ripeness of the meat affects the temperature at which the color change occurs, ripened meat becoming gray at a lower temperature. The extreme browning on the surface of meat is accompanied by break- down of surface proteins and fat, probably with liberation of sulfur and other compounds. Tenderness. Methods of estimating. Tenderness is one quality uni- versally desired in cooked meats. Tenderness may be estimated by subjective methods such as the ease of cutting or chewing. At present the most widely used method for comparing the tenderness of meat is the grading chart. The chart developed by the Cooking Committee of the National Project, TENDERNESS 221