NEUTRALIZATION otf SOUR CREAM 



167 



Table 29. Relative Action of Lime on Serum and on Curd in 

 Cream When Neutralized. 



The above figures show that while the serum of the neu- 

 tralized cream contained 51% more calcium, the curd contained 

 285.7% more calcium than was contained in the serum and curd 

 before neutralization of the cream. This evidence can leave no 

 doubt regarding the fact that the lime reacts with the casein and 

 that this action exceeds the action of the lime on the lactic acid 

 in the cream. 



Since casein is an acid body, it must follow that the readiness, 

 with which it enters into combination with the lime also causes 

 it to surrender its acidity in excess of the action of the lime on 

 the lactic acid. Table 30 shows that such is, in fact, the case. 



Table 30. Relative Action of Lime on the Acid of the Curd 

 and on the Lactic Acid in the Cream, Serum and Fat. 



Per Cent Acid in 



Table 30, unmistakably shows that the acid in the curd is 

 reduced to a greater extent than the lactic acid in the serum. 



It should be understood that the lower the point to which 

 neutralization of the cream is carried, the greater is naturally, 

 the relative reduction of the lactic acid in the serum. But even 

 in sample No 3, where the acidity in the cream was reduced to 



