Storage of eggs by home refrigeration and their use in food preparation
Eggs are used almost universally as food, and few other foods have been prepared in such a variety of ways. Although production and consumption will vary with the season, locality and cost, only three agricultural products produced in the United States exceed eggs in economic importance. As imports and exports are relatively small, egg production is primarily a domestic business.
When we consider the staggering number of eggs produced on farms in the United States, about 2,700,000,000 dozens, it is not surprising to note their wide use as food. In recent years the per capita consumption of eggs has averaged about thirty-eight pounds or twenty-five dozens. This per capita purchase of eggs increases as the per capita food expenditure rises.
Eggs bring food to man in a concentrated and easily utilized form. The edible portion of the egg contains approximately seventy-five percent water, thirteen percent protein, and twelve percent fat. The protein and the fat of eggs are of high biological value and compare favorably with those in milk. Eggs are also a significant source of the minerals and vitamins essential in the human dietary.
Their culinary value as well as their nutritive value makes eggs useful to the homemaker. The use of eggs in food preparation depends upon the protein which is both elastic and extensible. Eggs are used for leavening, binding, emulsifying and thickening. Many factors affect their performance in these uses, temperature, humidity and the length and type of storage. In addition, there may be individual variations in the newly laid eggs, such as differences in the viscosity of the white, which will affect their value in the various uses.
Since there are seasonal variations in egg production, eggs are selected in the plentiful seasons and stored for use in the seasons of lower production. Cold storage is the method most widely used in home and industry for the preservation of eggs. This process was developed to aid in retarding the changes which will naturally occur as the egg ages. This method seems to satisfactorily preserve the nutritive value and the normal performance of the egg in food preparation. Eggs commercially stored for as long as eleven months may be sold on the open market in competition with "fresh" eggs.
In spite of the success of the current preservation methods, it is reasonable that home or industrial storage may affect the performance of the eggs in some food preparation techniques. In order to determine the extent of changes in the value of eggs for emulsifying and leavening ater home refrigeration, the following study was begun. Mayonnaise and angel cakes clearly demonstrate these two uses of eggs, so this experiment is concerned with their preparation. The purpose of this investigation is to determine the length of time of home storage at which:
The egg white forms a foam of maximum stability.
The egg white gives the best performance in the preparation of angel cakes.
The egg yolk forms an emulsion (mayonnaise) of the greatest volume and stability.
In order to standardize the method of preparing these products an electric mixer has been used and methods developed with this beater.