Condensed Milk and Milk Powder 125 



Soluble and Insoluble Curd in Evaporated Milk 1 



The above figures show that, in the evaporated milk, practically 

 all of the coagulable albumin is changed to insoluble curd. The 

 brands analyzed contained evaporated milk condensed at the ratio 

 of 2 to 2.4 parts of fresh milk to 1 part of evaporated milk. The 

 soluble albumin found corresponds with the albumin not coagulable 

 by heat, normally found in fresh milk, times the ratio of concen- 

 tration. 



The casein is largely precipitated by the sterilizing heat,, but is 

 present in the form of very finely divided particles. This is due to 

 the mechanical shaking to which the evaporated milk is subjected 

 in the sterilizer and in the shaker. In many batches of evaporated 

 milk the precipitation of the casein during sterilization is so fine 

 that the product is perfectly smooth without shaking. The casein 

 in 'evaporated milk does not respond to the action of rennet as does 

 the casein in fresh milk. 



Milk Sugar. — The milk sugar is present in per cent, corre- 

 sponding with that of the original milk, times the degree of con- 

 centration. A portion of it has undergone oxidation (carameliza- 

 tion) due to the high sterilizing temperatures. It gives to the 

 evaporated milk a yellow to light brown color. The higher the 

 sterilizing temperature and the longer the exposure of the evaporated 

 milk to this heat, the darker is its color. 



1 Hunzifcer, Indiana Agricultural Experiment Station, Bulletins No. 134 and 143 



2 Hunziker, Indiana Agricultural Experiment Station, Twenty-fifth Annual Report, 1908 



