ACCUEACY IX COMMEECIAL GEADIXG OF OPEXED 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. 1 
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 still 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 hi 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. 2 
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. 
