170 



NEUTRALIZATION OF SOUR CREAM 



Table 32. Showing Neutralizing Action of Lime Water and 

 Sodium Hydroxide. 



The neutralizers were added in two installments. After the 

 first addition the cream was heated to 145 F. for one hour, then 

 enough more neutralizer was added to reduce the cream to the 

 neutral point. 



The lesser total acidity which was required for complete 

 neutralization, was undoubtedly due to the expulsion of carbon 

 dioxide, during the heating process. The slight decrease in the 

 acidity due to pasteurization is a matter of common experience. 

 These figures show a slight difference in the total neutralizing 

 effect between the sodium hydroxide and the lime water. This 

 is probably caused by the difference in dilution of the neutralized 

 cream, the greater dilution due to the lime water facilitating the 

 recognition of the end point in the titration. 



When neutralization is not carried to the end point, or neutral 

 point, the distribution of the Sodium hydroxide and the calcium 

 hydrate in solution differs somewhat; a slightly smaller propor- 

 tion of the remaining acid is lactic acid, when sodium hydroxide 

 is used, than in the case of lime water. 



This difference in the action of the two alkalies is materially 

 augmented when milk of lime (lime hydrate not in solution) is 

 used in the place of lime water. This is shown in Table 33. 



