4 MILK ANALYSIS 



Boiling produces coagulation of the albumin, some caramel- 

 ization of the sugar, and develops a greater facility of coales- 

 cence on the part of the fat globules. Enzyms are rendered 

 inert and most microbes are killed. 



When milk is allowed to stand, some of the fat rises gradually 

 and forms a rich layer, constituting cream. The proportion 

 of cream depends on several conditions. The amount formed 

 in a given time cannot be taken as a measure of the richness of 

 the milk. Water added to milk causes a more rapid separation 

 of the cream. Centrifugal action separates nearly all of the 

 fat. The following figures, given by D'Hout as averages, 

 show this effect: 



Whole Milk. Separated Milk. Cream. 



Specific gravity, 1032 1034 1015 



Total solids, 14.10 9.6 26.98 



Sugar, 4.70 5.05 3.32 



Casein, - - - - 3-5° 3-62 2.02 



Ash, 0.79 0.78 0.58 



Fat, ■ 5.05 0.20 21.95 



Buttermilk is the residue after removal of the butter by churn- 

 ing. Vieth gives the following analyses : 



Total Solids. Fat. Solids not Fat. Ash. 



9.03 0.63 8.40 0.70 



8.02 0.65 7.37 1.29 



10.70 0.54 10.16 0.82 



Whey or Milk-serum is the liquid freed from curd after 

 precipitation by rennet or acids. In most cases it contains a 

 notable amount of proteids, as shown in the following analyses 

 by Cochran: 



Milk Whey. 



Total solids. Solids not fat. Total solids. Proteids removed. 



9-27 9-13 6.62 2.51 



9-27 9-13 6.1 3.03 



14-05 8.3s 6.62 2.33 



7-71 7-6i 5.98 1.63 



8.91 8.71 6.50 2.21 



