Chapter 7

After trying out the luncheon menu given in the text, send with your answers to the Examination Questions a report of your success. In making out your report, simply write the name of the food and describe its condition by means of the terms specified in the following list:

Cream-of-Corn Soup: too thick? too thin? lumpy? well seasoned? milk curdled?

Cheese Souffle: light? heavy? baked sufficiently? shrunken? underdone?

Hash-Browned Potatoes: too brown? not brown enough? well seasoned? too much fat? too little fat?

Stewed Tomatoes: sufficiently cooked? well seasoned? too sour?

Baked Apples: well done? not well done? too brown? too dry? too moist? sufficient sugar?

Black Tea: too weak? too strong? hot? taste of tannin?

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EGGS

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VALUE OF EGGS AS FOOD

DESCRIPTION OF EGGS AND PLACE IN THE DIET

1. Eggs are of great importance in the diet, and to appreciate this fact fully the true nature of this food must be understood. For domestic use, the eggs of guinea hens, turkeys, ducks, and geese occasionally find favor, but as eggs laid by hens are the kind that is commonly used, it is to such eggs that this Section is devoted. A hen's egg may really be considered as an undeveloped chicken, because it contains all the elements required to build the body of the chick and provide it with the energy it needs to pick its way into the world. When it emerges from the shell, it is fully developed, and in a short time it begins an independent existence, seeking and finding its own food. The fact that eggs store so much nutritive material explains to some extent why they are a valuable source of food for man and why they are used so extensively. However, as in the case of milk, the elements that eggs contain are not in just the right proportion for the sole nourishment of a human being, so they must generally be used in combination with other foods.

2. Most persons are familiar with the appearance of eggs, but in order that satisfactory results may be obtained in their selection, care, and cooking, it will be necessary to look into the details of their composition. As is well known, an egg consists of a porous shell lined with a fine, but tough, membrane that encloses the white and the yolk and serves to protect them. The yolk is divided from the white by a delicate membrane, which permits it to be separated from the white when an egg is carefully broken. This membrane extends to each end of the shell in the form of a small cord, and it is so fastened to the shell as to hold the yolk evenly suspended. The porous nature of an egg shell is required to give air to the developing chick, but it is this characteristic that permits eggs to spoil as they grow old and are exposed to air, for through these minute pores, or openings, the water in the egg evaporates and air and bacteria enter. Of course, as the water evaporates and is replaced by air, the egg becomes lighter. Because of this fact, the freshness of eggs can be determined by placing them in water. When they are fresh, they will sink in cold water, but as they decompose they become lighter and will float.

Since it is known that the spoiling of eggs is due to the entrance of air through the porous shell, it may be inferred that their decay may be prevented either by protecting the shell so that air cannot enter or by keeping the eggs at so low a temperature that bacteria cannot grow. Although stored eggs always deteriorate more or less, both of these methods of preservation have proved very satisfactory, the former being used largely in the home and the latter finding its solution in cold storage. A knowledge of how eggs can be preserved, however, is of great value, for if there were no means of preservation and eventual marketing, the price of eggs would at times rise to actual prohibitive limits.

3. That eggs as an article of food are growing in importance is indicated by the fact that their production has come to be a large and widely distributed industry. Owing to the private consumption and sale of eggs, an accurate statement of the number of eggs produced is difficult to give. Still, in a report, the United States Bureau of Agriculture estimated the value of the yearly egg production at something more than three million dollars, with an allowance of about 210 eggs, or 17-1/2 dozen, per capita each year, or 4 eggs a week for each person. These figures, however, are only suggestive of the production, use, and value of eggs, for as the population increases so does the use of eggs. In fact, they are proving to be almost indispensable to the cook, the baker, the manufacturers of certain foods, and many others.

4. With the increase in the demand for eggs has come a corresponding steady advance in the money value of this product and, consequently, an increase in its price. The housewife who would practice economy in cookery can readily see, therefore, that with reference to the number of eggs required and the ways in which they are used, she must choose carefully the recipes and methods she employs. If the eggs are always considered a part of a meal, their use is seldom an extravagance, even at such high prices as they sometimes attain. On the other hand, if a dessert that requires the use of many eggs is added to a meal that is itself sufficient in food value, it is not unreasonable to regard such use of eggs as an extravagance. A point that should be taken into consideration in the use of eggs in the diet, especially when their price seems very high, is that there is no waste matter in them, unless the shell is regarded as waste. Therefore, they are often more economical than other foods that can be bought for less money.

It must not be understood, however, that eggs are used only as an article of diet. They are also a very important food ingredient, being employed in the preparation of many kinds of dishes. For instance, they are often used to thicken custards, sauces, etc.; to clarify soups and jellies; to lighten cakes, puddings, hot breads, and other baked mixtures; to form the basis for salad dressings; and to combine or hold together many varieties of food.

NUTRITIVE VALUE OF EGGS

5. Like milk, eggs are often spoken of as a perfect food. Still, as has been pointed out, they are not a perfect food for man, but they are of especial nutritive value and should be used freely in the diet just as long as their cost neither limits nor prohibits their use. An idea of how they compare with other nutritious foods can be obtained from Fig. 1, which shows that eight eggs are equal in food value to 1 quart of milk or 1 pound and 5 ounces of beefsteak. A better understanding of their food value, however, can be gained from a study of their composition.

6. Since an egg is an undeveloped chick that requires only the addition of warmth to develop it into a living, moving creature made of muscles, bones, and blood, it is evident that this food contains considerable tissue-building and energy-producing material. The exact proportion of this material, as well as the other substances found in eggs, is given in the food chart shown in _Essentials of Cookery_, Part 1. The chart relating to the composition of eggs points out that the edible portion of the whole egg consists of 73.7 per cent. of water, 14.8 per cent. of protein, 10.5 per cent. of fat, and about 1 per cent. of ash, or mineral matter. The protein, which is chiefly in the form of albumen, and the fat are the most digestible of these elements, while the mineral constituents are as valuable for the growing child as for the chick. When the total weight of an egg is taken into consideration, the shell constitutes about 11 per cent., the yolk 32 per cent., and the white 57 per cent. The composition of the yolk and the white differs somewhat, the yolk having the greater food value, a fact that is also clearly indicated in the chart. The white contains a larger proportion of water than the yolk, but the yolk contains the most of the fat and more protein and mineral matter, or ash, than the white. In addition, the chart shows that the number of calories to the pound of whole egg is 700, of egg yolk is 1,608, and of egg white is 265.

7. PROTEIN IN EGGS.--The nature of the food substances in eggs is of nearly as great importance as their amount, for they not only determine the value of this food in the body, but influence its cooking. That protein is present in both the yolk and the white is apparent from the fact that they coagulate when heat is applied. Because eggs are high in protein, containing 14.8 per cent. of this substance, they may be regarded as equivalent to a meat dish, and it is only when they are extremely high in price that they cannot be frequently substituted for meat to advantage. They are often used to take the place of milk, too, for eggs and milk are more alike in nutritive value than any other two protein foods; but, of the two, milk yields the cheaper form of protein. Like meat and milk, eggs are rich in all those food materials which enter into the construction of bone, muscle, and blood.

8. FAT IN EGGS.--A study of the food chart previously mentioned will show that eggs contain proportionately almost as much fat as protein and that nearly all this fat is found in the yolk. Since fat produces more heat or energy, weight for weight, than any other food substance, and since eggs contain neither starch nor sugar, it is evident that the fat of this food is the main source of the energy-producing material. Fat in eggs occurs in the form of an emulsion, or tiny particles, and, like the fat of milk, is very readily digested. It is for this reason that both of these foods are particularly well adapted to the diet of both children and adults. The presence of quantities of protein and fat and the absence of carbohydrate in eggs indicate that the proper thing to combine with this food, in order to have a well-balanced meal when eggs are eaten, is carbohydrate in some form.

9. MINERALS IN EGGS.--Eggs are especially valuable for the mineral salts they contain, chief among which are lime, phosphorus, sulphur, iron, potassium, and sodium. For this reason, the addition of eggs to any kind of diet supplies a large amount of the minerals that are needed for bone, blood, and tissue building. A favorable point concerning the minerals found in eggs is that they are not affected to any extent by cooking. Therefore, in the preparation of any dish, if eggs are added to other foods, that dish will contain an additional amount of mineral salts, plus the nutritive value of the eggs.

10. DIGESTIBILITY OF EGGS.--In connection with the discussion of the food substances of which eggs are composed, it will be well to note how these affect the digestibility of this food. But just what is meant by this characteristic with reference to eggs must first be understood. In some foods, digestibility may mean the length of time required for them to digest; in others, the completeness of the digestion; and in still others, the ease and comfort with which the process of digestion proceeds. In the case of eggs, digestibility refers to the quantity of this food that is absorbed, that is, actually dissolved and permitted to enter the blood stream. The nutritive value of eggs is not so high as would naturally be supposed, for, although the protein, fat, and mineral salts of an egg make up about one-fourth of its contents, one egg equals in nutritive value only 1/2 cupful of milk, a small potato, or a medium-sized apple. However, when the proportion of the nutritive material that the body retains from this food, or its digestibility, is considered, eggs rank extremely high, it having been determined by experiments that 97 per cent. of the protein and 95 per cent. of the fat are assimilated. A point worthy of note in this connection, though, is that eggs contain no cellulose, such as that found in grains, vegetables, and fruits. Therefore, in order to add the much-needed bulk to the diet, foods that do contain cellulose should be served with eggs.

11. Whether or not the cooking of eggs has any effect on their digestibility is a matter that has also been investigated. The results of the experiments made indicate that cooking makes some difference with the rate of digestion, but very little with its thoroughness. So far as the rapidity of digestion is concerned, there is very little difference between raw eggs and slightly cooked eggs; but hard-cooked eggs, although they may be digested as completely as soft-cooked ones, require longer time for the accomplishment of the process. This is due to the fact that the whites of hard-cooked eggs are so firm in texture that, unless they are finely chopped or thoroughly masticated, the digestive juices are not able to act on them quickly. As a result, portions of them may escape digestion or remain in the digestive tract for some time and decompose. For this reason, hard-cooked eggs are usually excluded from the diet of children and invalids, and even healthy adults should be careful to masticate them thoroughly.

SELECTION OF EGGS

12. On first thought it would seem as if there is very little to guide the housewife in the selection of eggs, it being extremely difficult to tell from their external appearance whether or not they are fresh or stale. As a rule, she must trust largely to the honesty of the person from whom she buys eggs. Still she need not depend entirely on the dealer's word, for, at least to a certain extent, there are ways in which she may judge the quality of eggs. Because of the great value of eggs as a food and for cooking purposes, it is important that the housewife make use of all available information on this matter and, in addition, become familiar with the trade practices in the egg industry.

13. MARKETING OF EGGS.--As is generally known, hens lay a large number of eggs in the spring of the year, but they do not lay readily in the cold winter months; and not alone are the greatest quantities of eggs produced in April and May, but those laid at this time are of the best quality. Because of this condition and in order that the demand during the time of scarcity may be supplied, it is necessary that a considerable number of eggs be preserved when they are comparatively cheap and abundant. Also, in the preserving of eggs for future use, it is of the greatest importance that they be kept in the best possible condition and manner, so that when they are used, months after they are laid, they may be as good as it is possible to have them.

The advance made in storage and transportation methods in recent years has done much toward making the egg supply uniform all the year around. Not long ago, because of inadequate means of storage and shipping, eggs were sold only a short distance from the place where they were produced. However, with the coming of cold storage and improved methods of shipping, eggs have been changed from a perishable and more or less seasonable food to a staple one. Now it is possible to collect them in large quantities, to keep them for a considerable time before selling them, and to ship them long distances. To safeguard the public, though, authorities have set a time limit for the storage of eggs, the legal time they may be kept being 8 months. By this is meant that eggs placed in the warehouse in May must be released or sold in December; whereas, those stored in June must be released no later than January.

14. Eggs that have been kept too long in storage are characterized by a musty odor and flavor, the breaking of the yolk and its mixing with the white, and a watery condition of the white. Such eggs, of course, cannot be sold legally. Those which may be placed on the market are graded according to their freshness, cleanliness, size, cracks, and color. With the exception of their freshness, these points can be readily told from the appearance of the eggs; but, in order to determine whether an egg is fresh or not, it is generally put through a process known as _candling_, by which the interior condition of the egg can be ascertained.

In the grading of eggs, all those of the best size, color, and condition are sold under a particular trade name and bring a high or a low price, according to the grading. Others that are not so perfect are put in another grade and sell for prices that vary according to the demand. Eggs, of course, differ in appearance and in many cases they are sorted in order to satisfy the demand. For instance, in some localities, eggs having a brown shell sell for the highest price, while in other places, eggs having a white shell are in the greatest demand and bring the highest price. Unsorted eggs are not held in much favor and do not bring so good a price as those which are all one color. Many persons have an idea that the color of the shell of an egg bears some relation to its nutritive value and flavor. However, authorities on foods agree that, other things being alike, the edible portion of white-shelled eggs has essentially the same composition and nutritive value as that of dark-shelled eggs.

15. QUALITY OF EGGS.--The natural quality of eggs depends largely on the food of the hens and their conditions of living. Because of this fact, the selection, breeding, and care of fowls have developed into a science, particularly since the production of eggs has grown into an industry. When the quality itself is to be determined, all the characteristics of eggs must be taken into consideration; still there is one particular point on which the quality of eggs depends, and that is their freshness. Various agencies, however, are constantly at work to render this quality inferior. Chief among these are the molds and bacteria that pass through the porous shells of eggs that have been improperly cared for or have become contaminated by being allowed to remain in unclean surroundings. Such bacteria are responsible for the unpleasant flavors that are found in bad eggs. Because of their harmful effect, every effort should be made to prevent the entrance of the germs that cause decay, and, as has been stated, the best way in which to accomplish this is to protect the shell. If it is found that bacteria have entered, the eggs will become unfit for use quickly unless their growth is prevented. This may be done by storing the eggs at a temperature that will keep the bacteria dormant, or inert.

16. If the eggs are kept under the proper conditions, they will not actually spoil for a long time; but it is seldom that they are not more or less affected by storage of any kind that covers a period of several months. One change that can always be looked for in such eggs is in the air space at the broad end. When an egg is first laid, this air space is small, but since the water contained in the egg slowly evaporates through the porous shell it increases in size as the egg grows staler. For this reason, the freshness of an egg can often be determined by the size of this air space.

In addition, the purposes for which eggs are used are somewhat affected by their storage. A stale egg, although it may not be actually spoiled to the extent that it cannot be used as food, will not produce such good results in a cooking process as a fresh egg, especially if it is used for leavening. In fact, it is impossible to produce the desired results with eggs that have undergone a certain amount of change, even though their odor and their flavor do not indicate that they are spoiled.

17. JUDGING THE QUALITY OF EGGS IN THE MARKET.--While, as has been mentioned, the housewife must depend considerably on the dealer's word as to the freshness of the eggs she purchases, it will be well for her to be familiar with the trade names of eggs and their meaning. The names used differ, of course, in various localities, but all large distributors grade and name eggs in much the same way. In deciding on the grade to which eggs belong, a certain number of points are given for color, size, freshness, and appearance, and the sum total of these points determines the grade, a special name being given for each grade. For instance, eggs that can be graded 90 are called _extra fancy_; those which receive a grade of 80, _fancy_; those which are graded 70, _strictly fresh_; and those which can be graded only 60, _cooking eggs_. When eggs are put on the market under such names, it can be expected that the quality will correspond to the grade and the price will vary with the grade. Therefore, the trade name and the price are two of the principal ways in which the quality of eggs in the market may be judged.

18. Another way of judging the quality of eggs consists in observing the condition of the surface of the shell. When eggs are freshly laid, the shell is covered with a substance, called _bloom_, that gives it a feeling much like that of a thin lime coating deposited in a pan after water boils. This coating disappears gradually as the egg is exposed to the air, but as long as it remains, the egg may be considered as fresh and germ-proof. While this way of determining freshness is probably the quickest, it is possible that the quality of some eggs from which the bloom has recently disappeared has not been injured.

19. When eggs are selected in the market, certain points in their appearance should also be noted. If eggs of the best quality are desired, medium-sized ones that are uniform in size and color should be selected. With regard to shape, they should have a comparatively long oval shell, one end of which is blunt and the other, a sharp curve.

20. JUDGING THE QUALITY OF EGGS IN THE HOME.--After eggs have been received in the home, several simple tests for determining their freshness can be applied in addition to the ones already mentioned. A rather indefinite test, but one that is sometimes applied to determine the freshness of an egg, is to shake it. However, to be able to carry out this test successfully, it is well to understand the interior structure of an egg. Fig. 2 illustrates this clearly. At _a_ is shown the air space previously mentioned; at _b_, the spiral cords that run from the yolk to each end of the egg and hold the yolk in place; at _c_, the yolk; and at _d_, the white. When the water inside the shell evaporates, the yolk and white shrink so much that they can be felt moving from side to side when the egg is shaken. The staler the egg, the more pronounced does the movement become. This method should be applied only immediately before the egg is to be used, as the thin membrane between the yolk and the white and the spiral cords that hold up the yolk are liable to be disturbed by the shaking. If they are broken, the yolk will settle and finally adhere to the shell in case the egg is stored for any length of time after that.