MICROSCOPICAL EXAMINATION OF FLOUR. 



29 



GENERAL CONCLUSIONS ON LOW-GRADE FLOURS. 



1 . The commercial grades of so-called low-grade flours ranged from 

 2 to 10 per cent. 



2. The average total offal count obtained on all commercial low- 

 grade flours examined was 433. This indicated that not as much 

 attention was given to the purification of the stocks passing into 

 such flours as was done in the case of the stocks composing the 

 grades already considered. 



3. The data obtained on the low-grade flours milled from the dif- 

 ferent wheats are summarized in Table 36. 



Table 36. — Limitations and average counts on bran particles and hairs for low-grade 



flours. 





Type. 



Bran particles. 



Hairs. 





Variation. 



Average. 



Variation. 



Average. 





169 to 353.... 

 143 to 402.... 

 100 to 397.... 



273 

 302 

 279 



88 to 335 

 27 to 261 

 59 to 183 



182 





140 





109 







EXAMINATION OF EXPERIMENTAL SERIES OF FLOUR. 



In connection with the examination of commercial flours it was 

 considered advisable to examine samples of flour whose composition 

 was definitely known, as far as the wheat from which they were milled 

 and their constituent streams were concerned. The information in 

 regard to the commercial samples was definite enough in so far as 

 the milling operator was able to judge. 



The samples of flour employed in this part of the investigation were 

 milled under the personal supervision of B. C. Winslow, food and 

 drug inspector, Bureau of Chemistry, United States Department of 

 Agriculture. The samples were prepared at a plant at Lyons, Kans., 

 a portion being milled from a No. 2 Nebraska hard winter wheat, crop 

 of 1914, containing from 25 to 35 per cent of yellow berry wheat, and 

 another portion from a Kansas No. 2 hard winter wheat. Each type 

 of flour was subjected to three degrees of bleaching, thus making 

 three samples for each type. Four types of flour were made from 

 each wheat, a 70 per cent, a 90 per cent, a 97.5 per cent, and a 27.5 

 per cent. In the case of the Kansas wheat a fifth type, a 2.5 per cent, 

 was made. The component streams that passed into each type and 

 the results of the examinations made were as follows: 



THE 70 PER CENT TYPE OF EXPERIMENTAL FLOUR. 



COMPOSITION. 



First sizing? flour. 

 Second sizings flour. 

 First middlings flour. 

 Second middlings flour. 

 Third middlings flour. 



Fourth middlings flour. 

 Fifth middlings flour. 

 Fine tailings flour. 

 Coarse tailings flour. 



