Foods, their selection and preparation

Hold the roast by placing the fork firmly between the ribs on the left side. Cut down between the ribs, allowing one rib to a slice. Lift the slice on the knife blade, using the fork to steady it. Alexander, Lucy M., and Yeatman, Fanny Walker. Meat for Thrifty Meals , Farmers Bul¬ letin No. 1908, U.S. Department of Agriculture, Washington, D. C., 1941. Cullen, M. O. How to Carve Meat , Game and Poultry. McGraw-Hill Book Company, New York, 1941. Halliday, Evelyn G., and Noble, Isabel T. Hows and Whys of Cooking, 3d ed., Chap. X. University of Chicago Press, Chicago, 1944. Lowe, Belle. Experimental Cookery, 3d ed., Chap. VIII, pp. 240-282. John Wiley & Sons, New York, 1943. National Live Stock and Meat Board. Cooking Meat in Quantity , rev. ed., 1946; Meat and Meat Cookery, 1949; Ten Lessons on Meat , 6th ed., 1943. Chicago. [216] Gelatin and Its Use in Food Preparation Gelatin is a purified food product containing a single protein. It is formed by heating in water bones and animal tissues containing a protein called collagen. In dry form gelatin is a clear, amorphous substance with a yellowish tinge. It is insoluble in cold water but dissolves in hot liquids, 95° F. or above. While gelatin will dissolve when added directly to hot water, it goes into solution more quickly after soaking in cold water. This preliminary soaking causes it to swell and increase the surface exposed to the solvent action of the hot liquid. On cooling, solutions of gelatin thicken and if they are sufficiently concentrated (about two per cent) a semisolid mass called a "gel” is formed. This characteristic makes gelatin useful in food preparation. SOURCES In the home, gelatin is formed during the making of meat soups. The long, slow cook¬ ing required to extract the flavor in making meat stock changes the collagen present in connective tissues, tendons, and bones to gelatin. These soups usually contain sufficient gelatin to form a gel when cold. Veal joint bones are used in making soups when a high gelatin content is desired. Before gelatin was generally available commercially, it was prepared at home for use in desserts from the foot bones of a calf. In a young animal these bones are rich sources of collagen. Old cookbooks often refer to desserts prepared from "calf's-foot jelly".” Commercial Gelatin. Gelatin is now a byproduct of the meat-packing industry. It is prepared by hydrolysis of the collagen from parts not useful for other purposes, such as tendons and bony pieces, high in cartilage and connective tissue. This hydrolysis begins at 176° to 196° F. and is hastened by use of higher temperatures or by boiling with acid. In the commercial manufacture of gelatin, low temperatures are used, and no acid, since the more drastic treatment tends to break down the gelatin into simpler products which would not form a gel. Gelatin is not a complete protein. It lacks two important amino acids and two others are present in smaller amounts than are necessary for tissue building. Since the amount used in most dishes is small, gelatin does not, in itself, make any important nutritive contribution to the diet. It is useful, however, in the preparation of attractive and palatable dishes from other foods. The food value of gelatin dishes depends largely upon the added ingredients.