UNSWEETENED ConDENSED Miik DEFEcts 265 
spection, that the steam-distributing pipe is in proper operating 
condition, Tf these precautions fail to remedy the trouble, then 
the entire process is inadequate and either more heat, or longer 
exposure to the same heat is necessary. 
Spitzer and Epple! investigated a case of bitter evaporated 
nulk, in which the troublesome organism appears to have been 
of a different type than was the case in the bitter evaporated 
milk epidemics under observation by Hunziker, as described 
above. Spitzer and [pple found the bitterness to be due to the 
presence in the evaporated milk, of an organism that corresponds 
with Migula’s (1900) classification of Bacillus panis as described 
by Lawrence and Laubach." 
This organism is a non-motile bacterium, rod-shape, with 
rounded ends and measuring about .4 by 2.0 microns. It is spore- 
bearing, the spores forming readily in 48 to 72 hours and ap- 
pearing usually near the center of the rod. The organism is 
capsulated and is very resistant to heat. Spitzer and Epple 
found it to survive a temperature of 250 degrees F. for 8 minutes, 
but was destroved at the same temperature upon 10 minute 
exposure. ‘The organism does not form gas, it does not swell 
the cans, nor does it coagulate the casein. The contents of the 
cans appear perfectly normal to the eye, the only change noticeable 
is the intensely bitter taste. It is an active proteolytic germ 
capable of secreting enzymes which are proteolytically active, 
rapidly breaking down the proteids of milk into large quantities 
of peptones and lower nitrogenous compounds of complex nature. 
The authors suggest that the excessive peptonizing function of 
this organism may he the primary cause of the bitterness. 
The description of the cultural characteristics and thermal 
death-point of this organism suggests that the presence of this 
germ in the evaporated milk, and the spoilage of the product, 
are not due to a faulty process of sterilization, but are the result 
of conditions in the factory that permit this germ to lodge and 
to contaminate the milk. Unsanitary condition of pipes, pumps, 
homogenizer, filling machine, ete.. would be the most likely 
breeding places and sources of contamination. 
1 Spitzer and Epple, Bitterness in Evaporated Milk, Journal of Dairy 
Science, Vol. III, 1920. 
2Lawrence and Laubach, Studies on Aerobic, Spore-bearing, Non-path- 
ogenic Bacteria, Journal of Bacteriology, Vol. I., p. 493. 
