NEUTRALIZATION OF SOUR CREAM 



169 



added to the cream shows no reduction in the acidity as deter- 

 mined by Mann's acid test. 



Table 31 demonstrates that sodium hydroxide, such as is 

 used in the acid tests, does indicate the total acid in the cream, 

 including the lactic acid, curd acid and fat acid. Its action is 

 very nearly equal to that of lime. The figures in this table were 

 analyzed, for percentage of acidity, separately. The table shows 

 that the sum of the acid in the components the serum, curd and 

 fat of the cream is practically equal to the acid in the original 

 cream. 



Table 31. Per Cent Acid in Unneutralized Cream and Its 



Components. 



Per Cent Acid in Cream and 

 Components of Cream Its Components 



"-" acidity in total components less than acidity in cream. 

 " + " acidity in total components more than acidity in cream. 



Further evidence of the fact that sodium shows similar 

 preference for curd as lime does may be found in Table 32. In 

 this experiment the neutralizing action of the lime water (lime 

 hydrate in solution) and sodium hydrate is shown. Here neutrali- 

 zation was carried to the neutral point. The action of the two 

 alkalies was very similar. 



