STATUS OF PASTEURIZATION OF MILK. 



17 



In milk pasteurized at 145 F. the great increase in the proportion 

 of the acid-coagulating and acid groups is plainly shown. The per 

 cent of the alkali and peptonizing groups is reduced. At 160 F. 

 the total-acid group is still the largest, but the acid-coagulating 

 group is made up of bacteria which coagulate very slowly. At this 



'62.ec. 



77C. 82.2C. 



93.3 



FIG. 1. The hypothetical relation of the bacterial group to raw and pasteurized milk. 



temperature the alkali group is greatly reduced, and the peptonizing 

 reduced to the minimum. At 170 F. the total-acid group remains 

 about the same, but the organisms produce acid and coagulate the 

 milk very slowly. The alkali group is practically destroyed although 



