7 2 



DAIRY TECHNOLOGY 



4. Toxic Properties Remain in Milk. Many bacterial 

 toxines are destroyed by heat, but others are not; hence it 



is argued that pasteurized 



Cold Raw 



Milk 1' 



V Outlet 



Outlet for Cold 

 Pasteurized MTllr 



milk may still be an un- 

 wholesome product. 



The existence of toxines 

 in market milk has been 

 largely inferred, not dem- 

 onstrated. If heat-resist- 

 ing toxines exist in milk, 

 the raw product will be 

 just as toxic as the heated, 

 and probably more so, be- 

 cause heating would stop 

 the development of the 

 toxines. 



5. Pasteurization Covers 

 Defects in Milk. Pas- 

 teurization may be used 

 to hide the age of milk, 

 so that the surplus from 

 one day may be disposed 

 of on the following day. 

 By re-pasteurization, milk 

 might be held for a long 



without showing its 



cooler. (Circular 184, Dairy Division, j j... 



aged condition. 



FIG. 4. Sectional view of a regenerative 

 cooler. (Circular i* 

 U. S. Dept. of Agr.) 



The re-pasteurization of 



milk, however, is prohibited by law in some cities. Such a 

 practice is not conducive to securing a high-grade product and, 

 so far as known, does not obtain under commercial conditions. 

 6. Affects Flavor and Creaming Property. When milk 

 has been subjected to a high temperature the cream rises 



