466 



MANUAL OF MILK PRODUCTS 



not killed and there is also more or less chance for contamination 

 before the condensed milk is put into the tin cans and hermeti- 

 cally sealed. Unless these organisms are killed they will mul- 

 tiply rapidly and spoil the product. It is therefore necessary 

 that the milk be completely sterilized after it has been sealed in 

 the cans. This is done by subjecting it to steam heat under pres- 

 sure in a large sterilizer or autoclave, as described on page 461. 

 The temperature used and the time of exposure must be suffi- 

 cient to absolutely insure complete sterilization. If this process 

 is properly done, the milk may be kept almost indefinitely. 

 Incomplete sterilization has been the cause of severe financial 

 losses to the manufacturer of unsweetened condensed milk. 



Richmond gives 

 milk as follows : 



COMPOSITION 



the composition of unsweetened condensed 



Sample 



Water 



Fat 



Milk-sugar 



Protein 



Ash 



1 

 2 

 3 



per cent 



63.47 

 62.40 

 63.07 



per cent 



10.22 

 11.91 

 10.86 



per cent 



12.98 

 13.04 

 13.38 



per cent 



10.30 

 9.68 

 9.80 



per cent 



2.07 

 2.14 

 2.21 



TESTING UNSWEETENED CONDENSED MILK 



The ordinary Babcock method has been recommended for 

 determining the percentage of fat in evaporated milk, but 

 Hunziker 1 found that this method did not give satisfactory 

 results. He recommends the following modifications of the 

 Babcock method as giving accurate and satisfactory results. 



Directions for Modified Babcock Test with Unsweetened 

 Condensed Milk (Hunziker) x 



apparatus : 

 One cream balance. Ten per cent milk test bottles. 



One 17.6 c.c. pipette. One Babcock centrifuge. 



One 17.5 c.c. acid measure. Commercial sulfuric acid, specific 



One 50 c.c. glass beaker. gravity 1.82 to 1.83. 



1 Indiana Bui. 134. 



