IMPROVED METHODS FOR FAT ANALYSIS. 



E. B. HOLLAND, J. C. REED AND .1. P. BUCKLEY. ^ 



Introduction. 



Experiments in animal nutrition have constituted a prominent line of 

 investigation at the Massachusetts Agricultural Experiment Station ever 

 since its organization, and numerous attempts have been made to deter- 

 mine the effect of feed on the composition of the resulting butter fat. '^ 

 These experiments extended over a number of years and required the 

 analysis of many samples of fat. A careful study of the technique of fat 

 analysis, in so far as the more conunon group methods are concerned, 

 was undertaken at the outset and has been continued to the present time. 

 With increasing experience, plans were formulated for a systematic corre- 

 lation and standardization of the various processes, and considerable 

 progress has been made in that direction. The object was to promote 

 accuracy by greater uniformity and simplicity of methods, embracing 

 definition of terms, principles involved and details of manipulation, in- 

 cluding reagents, apparatus and glassware. A report on "Methods for 

 Fat Analysis"^ was published some years ago. 



Innumerable modifications suggested by foreign and American investi- 

 gators in addition to those resulting from our own initiative have necessi- 

 tated a complete revision of former methods. While these in turn will be 

 superseded in the hght of subsequent progress, they are offered in the 

 hope that they may prove of service to fellow workers in oils and fats. 



At the outset oils, fats and waxes are defined, classified, and a synopsis 

 of composition given in order that the value of the data contributed by 

 the various determinations whereby the "structural" composition of the 

 product is evolved may be fuUj'- understood. The organoleptic tests are 

 merely enumerated, as their application is self-evident. They are emploj^ed 

 in classification, are very serviceable in identification, and particularly 

 valuable in discriminating as to quahty or grade, for which experience 

 and general knowledge of the trade are essential. 



The more prominent physical tests are of such a well-known character 

 that time is not taken to consider their special modifications. They 

 furnish a certain amount of confirmatory evidence, and are occasionally 

 employed for "cuUing" suspicious samples. With lubricating and illum- 



' Mr. Reed was associated in the earlier and Mr. Buckley in the later stages of the work. 

 2 Rpts. HatchExpt. Sta., 13, pp. 14-33 (1901); 14, pp. 162-168 (1902); 16, pp. 45-62 (1904). Mass. 

 Agr. Expt. Sta. Rpt. 21, Pt. 2, pp. 66-110 (1909). 



« Rpts. Mass. Agr. Expt. Sta., 21, Pt. 2, pp. 120-138 (1909); 22, Pt. 1, p. 139 (1910). 



