190 BACTERIOLOGICAL METHODS 



time, until they finally become unsuitable for consumption. If 

 fresh-laid eggs were thoroughly cleansed and sterilized externally, 

 coated with sterilized wax, tallow, paraffin or placed in liquid 

 glass and then put in cold storage, they would no doubt remain 

 wholesome for a period of 5 months to i year. Under the 

 usual conditions, cold storage eggs show marked deterioration 

 in the course of 2 or 3 months ; as indicated by loss of 

 moisture, yellowing of the albumen, softening of the yolk, loosen- 

 ing, increase in size of the air chamber and by the increase in the 

 bacterial count. The increase in the size of the air chamber is 

 due to the shrinkage of the egg mass, resulting from the loss of 

 moisture. According to Greenlee,^ the loss in weight of eggs 

 is due to evaporation of moisture to the external atmosphere but 

 the decrease in moisture of the white is not wholly due to external 

 evaporation, as the yolk takes up a part of the moisture, thus 

 increasing the moisture and weight of the yolk and also account- 

 ing for the increased liquidity and explaining the tendency on the 

 part of the yolk to rupture and the white to gelatinize. Fresh 

 eggs break well, whereas old eggs, including those kept in storage, 

 break badly as a rule. The egg mass does not leave the shell 

 readily, the yolk may be adherent to the shell, likewise the white, 

 and the yolk membrane ruptures easily and the result is generally 

 a mess. 



Evaporated, dried and frozen eggs have come into extensive 

 use in recent years. For these purposes, the cheapest and hence 

 the poorest market eggs are generally employed. There is indeed 

 an attempt made to cull the bad eggs at the factory, but this is, 

 as a rule, not done in an efficient manner. The eggs are usually 

 broken by women and the egg mass is thoroughly mixed and 

 dried by spraying into a drying chamber or by spreading on a 

 drying belt, or the drying may be done in very shallow pans. 

 Of course the temperature must be kept below the coagulation 



1 Deterioration of Eggs as shown by Clianges in the Moisture Content. Circular 

 83, Food Research Laboratory, Bureau of Chemistry, Aug. 20, 1911. 



