234 maine agricultural experiment station. 1908. 



Examination oe Graham Flours. 

 Two samples of graham flours were recently sent to this Sta- 

 tion for examination. One of these (Lab. No. 5 191) was milled 

 in this State under such conditions that its genuineness was 

 beyond question. The second sample (Lab. No. 5190) bore the 

 brand of a well known milling firm of the middle west. For 

 some reason this second flour had fallen under the suspicion 

 of the parties sending it, who believed it to be a "made up" 

 flour, i. e., a low grade white flour mixed with bran. As previ- 

 ous complaints of inferior products of this character had reached 

 the Station, it was thought advisable to make a comparative 

 study of these two flours. 



MECHANICAL ANALYSIS. 

 The samples were subjected to a mechanical analysis, two 

 sieves being used for the purpose, one having 20 and the other 

 40 meshes to the inch. The coarse portion which failed to pass 

 the 20 mesh sieve is here called bran. That passing the coarse 

 sieve and retained by the second is here referred to as the middle 

 product; while that passing the 40 mesh sieve is called fine 

 flour. The results are shown below. 



Bran Middle product Fine flour 



Lab. No. Per cent. Per cent. Per cent. 



5190 8 6 86 



5191 7 30 63 



GENERAL CHARACTERISTICS. 



A microscopical examination of the brans revealed no marked 

 differences except in the color and opacity of the various coat- 

 ings. The aleurone cells were about equally abundant in the 

 two samples. In the case of the lighter bran there seemed to be 

 a somewhat larger proportion of the apical hairs, but this may 

 not indicate a closer separation in one case than in the other, 

 but rather a characteristic of the grain itself. 



The most marked physical difference in these flours is in the 

 relative size of the constituent particles. In the western flour 



