UNITED STATES DEPARTMENT OF AGRICULTURE 



BULLETIN No. 524 





Contribution from the Bureau of Chemistry 

 CARL L. ALSBERG, Chief 



Washington, D. C. 



PROFESSIONAL PAPER 



May 7, 1917 



DETECTION OF LIME USED AS A NEUTRALIZER 

 IN DAIRY PRODUCTS. 



By H. J. WiCHMANN, Assistant Chemist, Food and Drug Inspection Laboratory, 



Denver, Colo. 



CONTENTS. 



Introduction 1 



Methods of analysis 3 



Analysis of unneutralized creams 5 



Analysis of dairy products made from un- 

 neutralized creams 6 



Influence of liming on composition of dairy 



products 8 



Effect of impurities in the salt on the percent- 

 age of calcium oxid in the salt-free ash 15 



Interpretation of results 19 



Use of lime to renovate old storage butter 20 



Summary 22 



INTRODUCTION. 



The use of lime by central-station creameries before pasteurization 

 for the purpose of reducing the acidity of cream before churning 

 has assumed considerable proportions. The cream is bought directly 

 from farmers at the various cream stations and then shipped in an 

 unneutralized state to the centralizing creamery to be manufactured 

 into butter. On arrival it is graded into two classes, according to its 

 taste and smell rather than its acidity. As the cream often has been 

 shipped several hundred miles to the central plant, it frequently 

 arrives in a very old and sour state, sometimes with an acidity of 

 over 1 per cent lactic acid. Cream with a "bad" taste or foreign 

 odor is churned into second-grade butter. If the cream is too sour, 

 lime is added in order to reduce the acidity to 0.3 or 0.4 per cent 

 lactic acid. The creameries claim to be able to make a good grade 

 of butter even from a very sour cream by the use of lime, and the 

 butter thus made is said to grade a number of points higher than 

 that made from the same cream not neutralized. Hence it has be- 

 come a common practice, especially in summer when it is difficult to 



Note. — This bulletin will be useful to officials of State , dairy and food departments. 

 74363°— Bull. 524 — 17 1 



