COMPARISON" OF AMERICAN WHEATS. 



9 



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TO TO TO "TO TO TO TO 



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Figure 6 would seem to prove the hypothesis that the reason for this 

 relationship lies in the evaporation of moisture during the milling 

 process. It shows that there is a very regular increase in milling 

 loss as the moisture content increases. 



FLOUR YIELD AND WEIGHT PER THOUSAND KERNELS. 



That there might be a relationship between milling yield and 

 average weight of kernels was suggested by several seemingly perti- 

 nent facts. Plump or well-filled kernels naturally have a higher 

 weight than shriveled kernels, and that the former are superior in 

 quality as far as milling yield is concerned is evident. Likewise, field 

 damage from sprouting, leaching, and other causes tends to decrease 

 the weight of the 

 kernels somewhat, 

 and these facts 

 bear a direct rela- 

 tionship to mill- 

 ing quality. Fig- 

 ure 7 presents 

 graphically the 

 results of the 

 study of these 

 two factors in re- 

 lation to each 

 other. It will be 

 noted from this 

 that the weight 

 per 1,000 kernels 

 apparently is not 

 a very good indi- 

 cation of milling 

 yield. Only in 

 the case of badly 

 shriveled samples having an unusually low weight does this factor 

 parallel low flour yield. Two or three factors seem to contribute 

 toward this result. The first and probably most important are 

 varietal differences. Some varieties of wheat have comparatively 

 small kernels, yet give as good a flour yield as wheat of other varie- 

 ties having much larger kernels. Then, again, seasonal and general 

 environmental conditions cause variations in the size of kernels 

 which do not seem in all cases to be accompanied by corresponding 

 changes in milling yield. One factor related to this is the moisture 

 content, an increase in which also increases the weight of kernels, 

 but this is accompanied by a decrease in flour yield. 

 91418°— Bull. 557—17 2 



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73 



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Fig. 



207 23S~ SOT SO 2 7 



6. — Diagram showing the relation between the loss in 

 milling and the moisture content of the wheat. 



