Page:Mrs Beeton's Book of Household Management.djvu/176

132 Albumin.—Albumin is the most valuable nutritive substance contained in meat; it and its allied substance myosin are soluble in cold water, but coagulate or harden almost immediately they come in contact with boiling water, or with water a few degrees below boiling point; and it is the knowledge of these important facts which enables us to retain the juices in the meat in roasting and boiling, and extract all the goodness from it in making soup. The chemistry of this will be easily understood by minutely examining the thread-like fragments of meat that have been subjected to a long process of boiling. In the raw condition each separate fibre was intermixed with and surrounded by albumin, myosin, etc. In making stock, the meat is cut up into rather small pieces in order to expose a larger surface to the action of the water. If put into cold water and allowed to stand for some time the soluble substances, albumin, myosin, osmasome and salts are extracted. The salts and extractives (certain nitrogenous crystalline bodies) being readily soluble are dissolved at once, the albumin and myosin dissolve slowly and the gelatin becomes softened. When heat is applied its first gentle effect is to hasten the dissolving and softening processes, but as it approaches boiling point the albumin and myosin coagulate and appear as brown particles on the surface of the stock. The connective tissue which surrounds and binds the thread-like fibres together dissolves under the influence of heat, and yields gelatin to the stock. Should the mistake of putting the meat into boiling water be made the albumin on the surface of each piece of meat would immediately harden and imprison the juices of the meat, and thus protect them and the fibres from the softening and dissolving influence of the water. Consequently the stock would be thin and poor.

Gelatin.—The best stock and the best beef tea are not necessarily those which, when cold, form a jelly. The properties to which beef tea owes its valuable stimulating power are not derived from gelatin, but from the juices of the meat; of which juices more can be extracted from a beef-steak cut from a recently-killed animal, than from one that has been hung for some time, and yet obtained in a much larger proportion from ANY KIND of beef-steak than from the highly gelatinous shin of beef. Juicy beef produces well-flavoured, stimulating beef tea, but such a liquid, strained of its floating particles of coagulated albumin, has no value as a food, and notwithstanding its rich flavour of meat would be regarded as too thin and watery to form the basis of a good consommé, which must combine both flavour and substance. Therefore, in making stock, the extraction of the juices of meat by the process already indicated, should be followed by a long, slow simmering to soften and dissolve the connective tissue, tendons, etc., which yield a more transparent gelatin than that extracted from bones. Gelatin not only gives substance to the stock, but also makes it more nourishing, if that point need be considered in a liquid forming the basis of a