UNITED STATES DEPARTMENT OF AGRICULTURE 



BULLETIN No. 330 



Contribution from the Bureau of Plant Industry, Wm. A. 



Taylor, Chief, and the Bureau of Chemistry, 



Carl L. Alsberg, Chief 



&j?*<$ m ru 



J&F^ji. 



Washington, D. C. 



January 8, 1916 



THE MILLING OF RICE AND ITS MECHANICAL 

 AND CHEMICAL EFFECT UPON THE GRAIN. 



By F. B. Wise, Assistant, Office of Grain Standardization, and A. W. Broomell, 

 Assistant Chemist, Food-Control Laboratory. 



CONTENTS. 



Introduction 1 



Geographical distribution and value of 



the rice crop 1 



Structure of the rice grain 2 



Killing methods 4 



Evolution of rice milling 4 



Primitive methods 4 



Modern milling..-. 7 



Effects of milling on rice 14 



Mechanical effect 14 



Chemical effect 18 



Milled rice and its by-products 22 



Mechanical analyses and mill yields 22 



Chemical analyses 26 



Summary 29 



INTRODUCTION. 



GEOGRAPHICAL DISTRIBUTION AND VALUE OF THE RICE CROP. 



From early colonial days until the Civil War, rice was an impor- 

 tant crop in the coastal plains of South Carolina and the adjacent 

 States. During the past quarter of a century, however, the produc- 

 tion of rice in Louisiana, eastern Texas, and Arkansas has risen to a 

 preeminent position. Of the 1913 rice crop of the United States, 

 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 Ar- 

 kansas. The relative importance of the rice-producing areas of the 

 United States is shown in figure 1. With the opening of the great 

 southern prairies of Louisiana and Texas for rice culture and its 

 more recent development in Arkansas, the production of rice in the 

 United States has increased enormously. Not less striking, however, 

 have been the improvements in the methods of planting, harvesting, 

 thrashing, and milling. 



Much has been written about the new agricultural schemes for pro- 

 ducing the rice crop, but very little literature is available on the mill- 

 ing processes now in use. It is the object of this paper to describe 



10832°— Bull. 330—16 1 



