365 J 



No. 47. 



NOTE ON A PHYSICAL METHOD OF SEPAEATING THE FATS IN 



BUTTER-FAT. 



By FELIX E. HACKETT, M.A., Ph.D., 

 Professor of Physics, College of Science, Dublin, 



AND 



T. A. CROWLEY, A.R.C.Sc.I., 

 Assistant-Demonstrator, College of Science, Dublin. 



(Bead April 29. Printed August 21, 1924.) 



The texture of butter, an important quality in its marketing value, is controlled 

 primarily by the character of the butter-fat and the churning temperature and 

 also by the conditions incident to the churning, washing, setting, and working 

 of the butter. The most suitable conditions have been arrived at empirically, 

 but our knowledge of the actual constituents of butter-fat and their physical 

 properties is yet insufficient to give a full scientific explanation of the jDrocess 

 of butter-making. The work described in this note indicates a method of 

 carrying out a phj^sical analysis of butter and separating to some extent its 

 constituent fats, and so stuclying their physical properties. As the process 

 is slow and tedious, it has been considered desirable to give this account of 

 some preliminary obsei-vations before iindertaking a more extended investigation. 



In the course of an examination of the texture of diiferent butters, it was 

 noticed that those buttere which had the firmer texture gave a smaller grease 

 ring on filter-paper. No information on the nature of this oily diffusing 

 substance was found in the extensive literature on the butter industry, though 

 the question of the wrapping-paper for butter is discussed. Apparently the 

 subject has never Ijeen investigated. Probably as it was assumed that the fatty 

 acids were present in butter as triglycerides, it was concluded that this substance 

 must be olein M.P. - 4° C, or butyrin M.P. - 76° C. It is impossible, however, to 

 separate butyrin from butter-fat (1) by solution in hot alcohol in the same 

 way as from an artificial mixture of triglycerides. This and other experiments 

 have led to the view that the fatty acids are combined with glycerine in 

 butter mainly as mixed giycerides. Amberger (2) showed by examination of 

 the portion of the hydrogenated butter-fat soluble in alcohol that the original 

 fat contains butyrodiolein, butyro-palmito-olein, and oleodipalmitin. Of these 

 oleodipalmitin has a melting-point of 38° C, and solidifies about 28° C. The 

 butyro-eompounds do not appear to have been isolated. Amberger concluded 

 that the butter examined did not contain more than 3 per cent, of olem. 

 This result is confirmed bv the work described in this paper. The oil which 

 diffuses into filter-paper is mainly a substance which solidifies between 10° and 

 12° C, and liquefies about 19° C. From these constants it cannot be identified 

 with any of the giycerides recorded in Beilstein. 



The initial experiment was made with unpasteurized Irish butter several 

 weeks old. It was distributed in small pats on Whatman filter-papers previously 



SCIENT. PBGC. B.D.S., VOL. XVII, NO. 47. ° ^ 



