32 THE BUTTER INDUSTRY IN UNITED STATES [256 



in the milk. Water, however, is frequently contaminated 

 with typhoid and other disease germs, and when milk- 

 pails and milk-cans are washed with cold water and not 

 thoroughly sterilized with boiling water, a typhoid epidemic 

 is the result. This is not only a problem in the consump- 

 tion of city milk, but is also a source of danger in the con- 

 sumption of butter ; though the danger in milk consumption 

 is greater than in the consumption of butter for the reason 

 that the growth of bacteria in fat is slow and in salted 

 butter especially so. However, the bacteria that find their 

 way into the butter, while they cannot develop rapidly, are 

 nevertheless a menace to the public health, and it is especi- 

 ally important that the germs of typhoid, diphtheria, and 

 tuberculosis be either excluded from the cream by a system 

 of rigid inspection, which is well-nigh impossible, or by 

 pasteurization. 1 



Milk contains certain enzymes which are believed to be 

 vital substances and are a near approach to " life ". 2 These 

 enzymes promote growth, and are therefore especially 

 beneficial in food for children. In the interest of public 

 health and from the point of view of dietary efficiency, the 

 pasteurization of cream to be used in making butter for 

 fresh consumption should not be at a temperature that will 

 destroy these enzymes. In order, however, that the keep- 

 ing quality of butter to be held in cold storage may be im- 

 proved, it is desirable to raise the temperature of pasteur- 

 ization to the death points of the enzymes, because investi- 

 gation indicates that they play a part in the deterioration 

 of butter. 3 



1 Vide, Circular 153, Bureau of Animal Industry, U. S. Department 

 of Agriculture. 



3 Ibid. 



3 Circular 189, Bureau of Animal Industry, U. S. Department of 

 Agriculture. 



