ACCURACY IN COMMERCIAL GRADING OF OPENED EGGS. 23 



A striking feature of the bacteriological study of musty eggs, ex- 

 cluding those with green whites, is their sterility. Of the 45 musty 

 eggs examined, only three, as shown in Table XIII, contained 

 bacteria. One had 350 organisms, and the other two had 200,000 

 and 150,000, respectively. The latter two eggs were from sample 

 41,192, which consisted entirely of eggs showing bacteria. The 

 ammoniacal nitrogen found in musty eggs is not excessive.^ 



Most of the musty eggs were from samples procured in the spring. 

 Sample 41147, which contained a large number of musty eggs, was 

 purchased from a grocery store located in one of the poorer sections 

 of a large city. The eggs had clean brown shells and showed prac- 

 tically no shrinkage on candling. The shells, however, did not have 

 the bloom characteristic of fresh eggs, but had rather the appearance 

 of having been washed. 



The most rational theory advanced by the trade regarding the 

 cause of musty eggs is that it may be due to absorption from sur- 

 rounding materials. If the musty odor is the result of such absorp- 

 tion, it is difficult to explain why it does not become weaker as the 

 egg ages in the shell or in the frozen state; also why the odor in 

 cake or confectionery does not always disappear in baking. Other 

 types of odors do not remain with such persistence. The cause of 

 musty eggs is stUl unknown. 



SOFT EGGS. 



Soft eggs represent a transition stage between edible and inedible 

 eggs. If the yolk breaks or is found to be broken when the egg is 

 opened, it is necessary to determine whether or not the egg is fit for 

 food. An egg with simply a ruptured vitelline membrane is not 

 rejected, but if other signs of deterioration, such as whitish streaks 

 in the yolk or a muddy white, are present, it is not considered 

 edible. (See Plate IV.) Sometimes it is found that the yolk of an 

 egg appears very weak before the candle and, on breaking, its outline 

 is practically lost because the yolk material has so quickly inter- 

 mingled with the white. This type of egg, shown in Plate V, is 

 called by the industry a ''runny egg" and is discarded. The soft 

 eggs with the whitish streaks in the yolk and the "runny eggs" 

 very closely approximate the degree of physical deterioration found 

 in mixed rots. Soft eggs sometimes have a soUr odor, in which 

 case they are heavily infected with bacteria.^ 



There were 447 soft eggs in the eggs under observation. Of these, 

 0.7 per cent were found to be sufficiently deteriorated to warrant 

 their exclusion from food products. About 20 per cent of these 

 rejected eggs showed infection. 



» Unpublished results. 2 U. S. Dept. Agr. Bui. 51, p. 61. 



