FoodNet

Experimental cookery

1932

Page 163

Presented as published in 1932. Historical recipes may not meet modern food-safety standards. Cook from the modern interpretation, not the original instructions.
interest in meat cookery, for both are found in the connective tissue betw^een the muscle fibers, but heat and moisture affect the two differently. Collagen. Table 24 shows that the white connective tissue contains nearly 32 per cent of collagen and about 7 per cent of elastin. Collagen in the presence of moisture and at high temperatures yields gelatin. Bogue states that collagen is changed to gelatin more rapidly at the boiling temperature of water, or at temperatures above boiling obtained by pres- sure, and more slowly at temperatures below boiling. The gelatin is dis- solved in the water or broth. If the meat is cooked long enough, the larger part of the connective tissue is dissolved, so that the muscle fibers may fall entirely apart. Sometimes in cooked meat only the outer portion of the fibers is separated and the inner portion is still connected. The surface of the meat reaches a high temperature before the interior of the meat, thus the collagen of the connective tissue near the surface may be changed to gelatin first. Elastin. Vandergrift and Gies have reported the yellow connective tissue as containing about 32 per cent of elastin and about 2 per cent of collagen. The elastin is a very resistant, firm protein and is not changed or affected by heat and moisture. In cooking, yellow connective tissue is not softened. Consequently cuts of meat containing large amounts of elastin in the connective tissue will be tough after cooking, whereas cuts containing large amounts of collagen may have part or all of the collagen changed to gelatin. 204 MEAT TABLE 25 Connective Tissue Proteins in Meat {Mitchell, Zimmerman, and Hamilton) Collagen Total Collagen Elastin and nitrogen nitrogen elastin No. Description of sample nitrogen in sample, in in nitrogen per cent percentage percentage in of total N of total N percentage of total N 1. Beef rib 3.19 8.4 6.4 14.8 7.9 7.2 15.1 4. Beef rib 3.35 4.2 4.2 8.1 8.2 12.9 12.4 5. Beef shank 3.42 7.5 6.2 14.4 12.0 21.9 18.2 6. Pork tenderloin 3.68 3.0 1.7 4.7 2.3 1.8 4.2 7. Chicken,compositebone- less meat from 2-lb. cockerels 3.63 19.6 5.2 24.8 8. Chicken, composite bone- less meat from 2-lb. pullets 3.48 17.8 18.0 3.7 4.1 21.5 22.1 11. Chicken, breast muscle from 3-lb. cockerel . . . 3.24 2.1 0.8 2.9 1.1 0.6 1.7 12. Chicken, thigh muscle from 3-lb. cockerel 3.21 2.4 3.7 6.1 2.0 6.5 8.5 13. Chicken, breast muscle from 3-lb. pullet 4.06 3.4 0.3 3.7 14. Chicken, thigh muscle from 3-lb. pullet 3.23 12.2 1.7 13.9 12.4 1.7 14.2 15. Chicken, breast muscle from 4-lb. cockerel 4.14 6.5 1.6 8.1 6.8 1.6 8.4 16. Chicken, thigh muscle from 4-lb. cockerel .... 3.69 11.9 1.8 13.8 13.5 2.4 13.9 LESS TENDER CUTS HAVE MORE CONNECTIVE TISSUE 205 Less tender cuts have more connective tissue. Data given in Table 25 are from the earlier work of Mitchell et al., so that the percentage of elastin given is too high, but the comparative amounts in different cuts are shown. In later work Mitchell and co-workers found that the percentage of elastin in muscle is small, but in general the less tender contain a larger proportion than the tender cuts.