206 CHEMICAL COMPOSITION 
solids. In other localities it may be difficult at certain seasons 
of the year, to incorporate more than 24 per cent. solids without 
injuring or destroying the marketable properties of the product.t 
Butter Fat.—The fat varies with the per cent. of fat in the 
fresh milk and with the degree of concentration. No fat is lost 
during the process of condensing and sterilizing.” It has been 
claimed by some that in the process of manufacture, the volatile 
fatty acids escape and that the evaporated milk therefore con- 
tains less fat than the fresh milk from which it is made, times 
the degree of concentration. If this were true the loss of fat in 
the evaporated milk would not exceed .25 of 1 per cent. But 
analyses show that the fat in the evaporated milk is entirely 
normal in composition and contains the same proportion of 
volatile fatty acids as the fat in the fresh milk. 
The Composition of Milk Fats in Evaporated Milk.’ 
Date of Reichert Melting Point of 
Meliss] Iodine Melting Point of Insoluble Fatty 
Manufacture Number Number Mixed Fats Acids 
August, 1908.......... 28.48 33.64 33.3 degrees C. 41.0 degrees C. 
November, 1908........ 29.52 33.60 33.4 degrees C. 41.2 degrees C. 
In the evaporated milk there is a strong tendency for the 
fat to separate out during storage and to churn in transportation. 
This is largely avoided by the proper adjustment of the steriliz- 
ing process and by use of the homogenizer. 
Proteids.—The proteids vary with the per cent. of total 
proteids in the fresh milk and the degree of concentration. 
Similar to the case of sweetened condensed milk, there is a ten- 
dency of a slight loss of proteids in evaporated milk due to 
mechanical adhesion of a part of the precipitated curd to the 
heating surfaces in the forewarmers and in the vacuum pan. 
Most of the coagulable milk albumin is precipitated. Fresh 
milk contains about .16 per cent. of albumin that is not coagu- 
lable by heat. The relation of soluble and insoluble curd is 
1 Hunziker, Indiana Agricultural Experiment Station, Twenty-first An- 
nual Report, 1908, pages 67-68. 
2? Hunziker and Spitzer, Indiana Agricultural Experiment Station, Bulletin 
No. 134. 
8 Hunziker, Indiana Agricultural Experiment Station, Bulletin No. 143. 
