Human Foods and Their Nutritive Value by Harry Snyder (dark academia books to read .TXT) 📕
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141. Use of Eggs in the Dietary.—When eggs are at the same price per dozen as meat is per pound, they furnish a larger amount of nutrients. In general, a dozen eggs have a little higher food value than a pound of meat. Eggs are usually a cheaper source of food because a smaller amount is served than of meat. When eggs are 25 cents per dozen, the cost of ten eggs for a family of five is less than that of a pound or a pound and a quarter of beef at 22 cents per pound. The meat, however, would furnish the larger amount of nutrients. Eggs are valuable, too, in the dietary because they are frequently combined with flour, cereal products, and vegetables, which contain a large amount of starch, and some of which contain small amounts of protein. This combination furnishes a balanced ration, as well as secures palatability and good mechanical combination of the foods. Eggs in combination with flour, sugar, butter, and other materials have equally as great a value as when used alone and as a substitute for meat.
Eggs vary in weight from 17.5 to 28 ounces, and more per dozen. They should be purchased and sold by weight. When stored, eggs lose weight. The egg cannot be considered as entirely germ proof, and care is necessary in its handling and use, the same as with other food articles. The cause of the spoiling of eggs is due largely to exterior bacterial infection.
CANNED MEATS142. General Composition.—Canned meats differ but little in composition from fresh meats. Usually during the process of cooking and canning there is a slight increase in the amount of dry matter, but the relative proportion of protein and fat is about the same as in fresh meat. It is frequently stated that the less salable parts are used in the preparation of canned meats, as it is possible by cooking and the addition of condiments to conceal the inferior physical properties. As to the accuracy of these statements, the author is unable to say. The shrinkage or loss in weight during canning amounts to from 30 to 40 per cent. The liquids in which the cooking and parboiling are done are sometimes used in the preparation of beef extracts. Salt, saltpeter, and condiments are generally added during the canning process. Saltpeter is used, as it assists in retaining the natural color and prevents some objectionable fermentation changes. In moderate amounts it is not generally considered an adulterant. An extensive examination by Wiley and Bigelow of packing-house products and preserved meats showed that of the latter only a small amount contained objectionable preservatives. The authors, after an extended investigation, reported favorably upon their composition and sanitary value, saying they found "so little to criticise and so much to commend in these necessary products." In this bulletin they do not classify saltpeter as an adulterant.[51]
Where fresh meats cannot be secured, canned meats are often indispensable. Usually the nutrients of canned meats cost more than those of fresh meats, and in their use as food much care should be exercised to prevent contamination after opening the cans. Occasionally the meat contains ferment materials that have not been entirely destroyed during cooking, and these, when the cans are stored in warm places, develop and cause deleterious changes to occur. Consequently canned meats should be stored at a low temperature. By recent congressional act, these preparations are now made under the supervision of government inspectors. All diseased animals are rejected, and the sanitary conditions under which the meat is prepared have been greatly improved. Formerly, the most frequent forms of adulteration were substitution of one meat for another, as the mixing of veal with chicken, and the use of preservatives, as borax and sulphites. While the cost of the nutrients in canned meats is generally much higher than in fresh meats, the latter are not always easily obtained, or capable of being kept for any length of time, and hence canned meats are often indispensable.
CHAPTER IX CEREALS143. Preparation and Cost of Cereals.—The grains used in the preparation of cereal foods are wheat, oats, corn, rice, and, to a less extent, barley and rye. For some of these the entire cleaned grain is ground or pulverized, while for others the bran and germ are first removed. In order to improve their keeping qualities, they are often sterilized before being put up in sealed packages. Special treatment, as steaming or malting, is sometimes given to impart palatability and to lessen the time required for cooking. As a class, the cereal foods are clean, nutritious, and free from adulteration. Extravagant claims are sometimes made as to their food value, and frequently excessive prices are charged, out of proportion to the cost of the nutrients in the raw material. Within recent years the number of cereal preparations has greatly increased, due to improvements and variations in the methods of manufacture.[56]
Cereal foods are less expensive than meats and the various animal food products. They contain no refuse, are easily prepared for the table, and may be kept without appreciable deterioration. Some of the ready—to-eat brands are cooked, dried, and crushed, and sugar, glucose, salt, and various condimental materials added to impart taste. Others contain malt, or are subjected to a malting or germinating process to develop the soluble carbohydrates, and such foods are sometimes called predigested. It is believed that the cereals are being more extensively used in the dietary, which is desirable both from an economic and a nutritive point of view. Special care is necessary in the cooking and preparation of cereals for the table, in order to develop flavor and bring about hydration and rupturing of the tissues, as explained in Chapter II.
144. Corn Preparations.—Corn or maize is characterized by a high percent of fat and starch, and, compared with wheat and oats, a low content of protein.[57] Removal of the bran and germ lessens the per cent of fat. The germ is removed principally because it imparts poor keeping qualities. Many of the corn breakfast foods contain 1 per cent or less of fat and from 8 to 9 per cent of protein. Coarsely ground corn foods are not as completely digested and assimilated as those more finely ground. As in the case of wheat products, the presence of the bran and germ appears to prevent the more complete absorption of the nutrients. Finely ground corn meal compares favorably in digestibility with wheat flour. Corn flour is prepared by removal of the bran and germ and granulation of the more starchy portions of the kernel, and has better keeping qualities than corn meal from which the bran and germ have not been so completely removed. At times corn flour has been sufficiently low in price to permit its use for the adulteration of wheat flour. The mixing of corn and wheat flours, however, is prohibited by law unless the product is so labeled. When combined with wheat flour, corn bread and various other articles of food are prepared, but used alone corn flour is not suitable for bread making, because its gluten lacks the binding properties imparted to wheat flour by the gliadin. It is essential that corn be used with foods of high protein content so as to make a balanced ration; for when it forms a large part of the dietary, the ration is apt to be deficient in protein. In a mixed dietary, corn is one of the cheapest and best cereals that can be used. Too frequently, however, excessive prices are charged for corn preparations that contain no more nutrients than ordinary corn meal. There is no difference between yellow and white corn meal so far as nutritive value is concerned.
Fig. 31.—Corn Starch.
145. Oat Preparations are characterized by large amounts of both protein and fat. Because of the removal of the hulls, they contain more protein than the original grain. The oat preparations differ little in chemical composition. They all have about 16 per cent of protein, 7 per cent of fat, and 65 per cent of starch, and are richer in ash or mineral matter than other cereals. The main difference is in method of preparation and mechanical composition. Some are partially cooked and then dried. Those costing 7 cents or more per pound do not contain any greater amount of nutritive substance than those purchased in bulk at about half the price. At one time it was believed that oats contained a special alkaloid having a stimulating effect when fed to animals. Recent investigations, however, show that there is no alkaloidal material in oats, and whatever stimulating effect they may have results from the nutrients they contain. Occasionally there is an appreciable amount of cellulose, or fiber, left in the oat preparations, due to imperfect milling. This noticeably lowers the digestibility. Oatmeal requires much longer and more thorough cooking than many other cereals, and it is frequently used as food when not well prepared. Digestion experiments show that when oatmeal is cooked for four hours or more, it is more readily acted upon by the diastase ferment and digested in a shorter time than oatmeal cooked only a half hour.[5] Oatmeal is one of the cheapest sources from which protein is obtained, and when well cooked it can advantageously form an essential part of the ration. Unless thoroughly cooked, the oat preparations do not appear to be quite so completely or easily digested as some of the other cereals.
Fig. 32.—Oat Starch Granules.
146. Wheat Preparations differ in chemical composition more than those from oats or corn, because wheat is prepared in a greater variety of ways. They are made either from the entire kernel, including the bran and germ, or from special parts, as the granular middlings, as in the case of some of the breakfast foods, and a few are made into a dough and baked, then dried and toasted. Some special flours are advertised as composed largely of gluten, but only those that have been prepared by washing out the starch are entitled to be classed as gluten flours.[58] For the food of persons suffering from diabetes mellitus physicians advise the use of flour low in starch, and this can be made by washing and thus removing a portion of the starch from wheat flour, as directed in Experiment No. 30. The glutinous residue is then used for preparing articles of food. Analyses of some of the so-called gluten flours show that they contain no more gluten than ordinary flour, particularly the low grades. A number of wheat breakfast foods are prepared by sterilizing the flour middlings obtained after removal of the bran and germ. These middlings are the same stock or material from which the patent grades of flour are made, and they differ from wheat flour only in mechanical structure and size of the particles. Where granular wheat middlings can be secured in bulk at the same price as flour they furnish a valuable and cheap cereal breakfast food.
Fig. 33.—Wheat Starch Grains.
As to the digestibility and food value, the wheat breakfast foods have practically the same as graham, entire wheat, or ordinary patent flour, depending upon the stock which they contain. Those with large amounts of bran and germ are not as completely digested as when these parts of the kernel are not included. Wheat preparations, next
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