EGGS AND THEIR VALUE AS FOOD. 13 



When beaten or whipped, eggs, and particularly egg whites, in- 

 close air bubbles, many more being inclosed by fresh eggs than by 

 packed or old eggs. When such beaten yolks and whites are added 

 to batters or doughs the air bubbles are distributed throughout the 

 mass, and when the dough is cooked the inclosed air expands and the 

 walls of the air bubbles become firm, with the result that the porous 

 structure is retained. Sponge cake and angel cake are familiar 

 examples of foods made light with eggs. It is interesting to note 

 that recipes for cakes and similar dishes to-day commonly call for 

 fewer eggs than those of a generation or two ago. The reason is 

 that, owing to the quite general use of baking powder, the house- 

 keeper is not so often compelled to depend upon eggs to make her 

 cakes light and need use only enough to give the desired flavor, color, 

 and texture. In considering the uses of eggs as an ingredient of 

 cakes and other dishes, it should be noted that they add materially 

 to the nutritive value of the dish as well as to its quality and 

 appearance. 



Besides their uses in foods of various sorts, eggs are often em- 

 ployed as a garnish. Hard-boiled eggs, for instance, cut into dif- 

 ferent shapes, are a common garnish for cooked greens or for salad ; 

 or, instead of being cut or chopped, the yolk may be put separately 

 through a ricer. 



White of egg is employed for icings, meringues, and confectionery, 

 particularly various sorts of cream candy, and for clarifying liquids 

 (see p. 14). 



Since eggs are especially rich in protein, combining them with 

 flour, starch, and sugar (typical carbohydrate-yielding foods) and 

 butter and cream, which are rich in fat, is perhaps an unconscious 

 effort to prepare a food which shall more nearly meet the require- 

 ments of the body than any one of the ingredients alone. When 

 eggs, meat, fish, cheese, or similar foods rich in protein are eaten, 

 such other foods as bread, butter, potatoes, etc., are usually served at 

 the same time, the object being, even if the fact is not realized, to 

 combine the different classes of nutrients into a suitable diet. The 

 wisdom of such combination, as well as of other generally accepted 

 food habits, was proved long ago by practical experience. The reason 

 has been more slowly learned. 



The total number of methods of serving and preparing eggs is 

 very large, but in nearly every case each is only a more or less elab- 

 orate modification of one of a few simple ways of cooking. Thus, an 

 egg in the shell is cooked by immersion in hot or boiling water or is 

 less commonly roasted. An egg removed from the shell may be 

 cooked in hot water or in hot fat. In the latter case it may or may 

 not be beaten or stirred. Combined with other materials to form 



