290 



. 1 (jricultv rn I ( 'hemistry. 



possesses the power of peptonizing casein, and pepsin, contained 

 in the rennet extract used. Whatever may be the cause of these 

 changes, there can be no doubt that during the curing process 

 the flavor and aroma are developed and that a considerable por- 

 tion of the insoluble nitrogenous bodies are converted into water- 

 soluble forms. The fat of cheese undergoes slight change during 

 ripening, a small proportion of the neutral fat being decomposed 

 and butyric and other fatty acids formed. The sugar which was 

 present when the cheese was first made also disappears after a 

 period of 7 to 10 days. Lactic acid is the main product formed 

 from the sugar, although other products, probably of great im- 

 portance to flavor development, are produced. 



The ripening of special kinds of soft cheese, such as Roquefort 

 and Camembert is attributed to such special ferments as molds, 

 introduced during the process of manufacture. The average 

 composition of various cheeses is given in the following table : 



Composition of Cheese. 



Under the United States pure food act, the following defini- 

 tions of cheese were established. 



(1) Whole milk or full cream cheese is cheese made from milk 

 from which no portion of the fat has been removed. 



(2) Skim milk cheese is cheese made from milk from which 

 any portion of the fat has been removed. 



(3) Cream cheese is cheese made from milk and cream or milk 

 containing not less than 6 per cent of fat. 



