STERILIZATION 



143 



hermetically sealed cans. Considerable advance has 

 been made in recent years in regard to the preparation 

 of such preserved, canned, milk, in that the boiled and 



FIG. 10. 



Kleemaim's high-pressure pasteurizer and regenerative heater, a, water of condensation 



b, to the cooler. 



burnt taste has been prevented by pumping the air out 

 of the milk before heating it and by the exclusion of 

 oxygen during heating, so that a high temperature is 

 possible and a safer sterilization is accomplished without 

 seriously affecting the taste. Another difficulty which 

 it has been necessary to contend with, the separation of 

 cream, and of butter formation during storage, seems 

 by degrees to have been overcome. 



For the purpose of sterlizing milk, instead of the 

 usual apparatus built according to the Fjord system, 

 tightly closed machines are used, so that the tempera- 

 ture of the milk can be raised above the boiling point, 

 and through these the milk is forced by means of a small 



