16 BULLETIN 839, U. S. DEPARTMENT OE AGRICULTURE. 



It is interesting to observe the variety of streams drawn upon for 

 the composition of different so-called patents, as well as the varia- 

 tion in the offal count of the stocks employed in the milling of such 

 finished flours. If space permitted, additional information could 

 be submitted to illustrate how variable the different mill stocks are 

 as far as offal content is concerned. In many instances where 

 lower-grade stocks have been employed in making a flour, however, 

 the finished product has usually been purified sufficiently to cause 

 the resultant offal count to be appreciably low. And in many cases 

 the contrary is true. 



EXAMINATION OF COMMERCIAL GRADES OF FLOUR. 



The assembled flours employed in this part of the investigation 

 were collected by B. C. Winslow, food and drug inspector, Bureau 

 of Chemistry, United States Department of Agriculture. As these 

 flours were milled under a variety of conditions, they necessarily 

 reflect such conditions in the finished product. The inspector gave 

 the following statement as to the designations applied to these 

 flours: "As a general thing, these names were used in harmony 

 with the usage of the mill where they were taken. The method of 

 assembling, with the streams, percentages, etc., were given when 

 feasible, and as correctly as possible from the information available. 

 The general terms 'patent/ 'clear/ and 'straight' were used to clas- 

 sify in a general way the assembled grades of flour, and vary with 

 each mill." 



With this information in mind, an attempt was made to apply the 

 microscopical method already described to an examination of these 

 products for the purpose of developing a system for the classification 

 of flours based on the offal content. A detailed discussion of the 

 actual data obtained from these tests, with a general summary on the 

 various so-called grades, follows. 



PATENT FLOURS. 



PATENT FLOURS MILLED FROM HARD WHEATS. 



Thirty-six patent flours said to have been milled from hard wheats 

 were examined microscopically, and their bran particle and hair 

 count determined. The commercial grade designations ranged from 

 40 to 94 per cent. In some instances the flour had been bleached; 

 in others it was bleached only lightly or not at all Table 16 gives 

 the results of this exa m ination. 



