THE MILLING OF RICE. 



29 



Table XII gives the chemical composition of samples of rice hulls, 

 bran, and polish secured by the writers at various mills. Attention 

 is called to the very high content of ash, crude fiber, and pentosans 

 and the corresponding low figure for ether extract and protein in 

 rice hulls. 



Table XII. — Chemical composition of rice hulls, bran, and polish. 





Constituents (per cent). 



By-product, type, and 

 grade. 



Mois- 

 ture. 



Ash. 



Ether 



ex- 

 tract. 



Crude 

 fiber. 



Pro- 

 tein. 



Pento- 

 sans. 



Calculated to moisture-free basis. 



Ash. 



Ether 



ex- 

 tract. 



Crude 

 fiber. 



Pro- 

 tein. 



Pen- 

 to- 

 sans. 



Hulls: 



Honduras No. 1 



Do 



6.96 

 6.28 

 6.12 



20.73 

 16.67 

 20.10 



0.22 



.78 

 .86 



42.00 

 29.98 

 36.08 



1.56 

 3.56 

 2.69 



20.24 

 16.11 

 18.14 



22.28 

 17.79 

 21.41 



0.24 

 .83 

 .92 



45.14 

 32.00 

 38.43 



1.68 

 3.80 

 2.86 



21.75 

 17.19 





19.32 









6.45 



19.17 



.62 



36.02 



2.60 



18.16 



20.49 



.66 



38.52 



2.78 



19.42 







Bran: 



Honduras No. 1 



Do 



9.32 

 9.91 

 9.39 



• 10. 79 

 10.37 

 11.33 



8.53 

 12.77 

 15.13 



12.49 

 10.92 

 12.54 



13.13 

 13.69 

 12.81 



10.16 

 9.74 

 11.40 



11.90 

 11.51 

 12.50 



9.41 

 14.17 

 16.70 



13.69 

 12.12 

 13.84 



14.48 

 15.19 

 14.14 



11.20 



10.81 





12.58 









9.54 



10.83 



12.14 



11.95 



13.21 



10.43 



11.97 



13.42 



13.21 



14.60 



11.53 







Polish: 



Honduras No. 1 



Do 



7.88 

 8.67 

 10.03 



7.37 



5.71 



7.02 

 4.96 

 5.67 



10.97 

 10.70 

 10.30 

 7.28 



3.74 

 2.82 

 1.68 

 2.34 



12.56 

 13.06 

 11.56 

 11.25 



4.58 

 4.37 

 3.59 

 3.92 



6.23 

 7.69 

 5.51 

 6.12 



11.91 



11.72 



11.45 



7.86 



4.06 

 3.09 

 1.87 

 2.53 



13.63 

 14.30 

 12.85 

 12.14 



4.97 

 4.78 





3.99 





4.23 









8.49 



5.84 



9.81 



2.65 



12.11 



4.12 



6.38 



10.73 



2.89 



13.23 



4.50 







SUMMARY. 



During the past quarter of a century the important rice-growing 

 area of the United States has shifted from the South Atlantic 

 coast to the Gulf States west of the Mississippi River and to the 

 prairies of Arkansas. Of the 1913 crop, valued on the farm at 

 $22,090,000, approximately 45 per cent was grown in Louisiana, 38 

 per cent in Texas, and 15 per cent in Arkansas. Greatly increased 

 production has been accomplished by the enlargement of mills and 

 the improvement of milling methods. 



The rice grain from the farm is covered with a hard, siliceous 

 hull. The hulled grain contains a germ, or embryo, located near one 

 end, and is covered with a light-brown bran coat which, when exam- 

 ined under the microscope, is found to consist of seven layers. Dur- 

 ing the process of milling, the hulls, the germ, six of the bran layers, 

 and a portion of the seventh are removed. 



A study of the evolution of rice milling in the United States shows 

 that the farm method of pounding the grain in a wooden mortar 

 with a pestle by hand was the earliest process. This was succeeded 



