8 BULLETIN 323, U. S. DEPARTMENT OF AGRICULTURE. 
Ill studying the protein of the various types of rice man}- factors 
seem to be of importance. Chinese white rice, which has a very 
small and very flinty kernel, contains in a water-free sample 9.17 per 
cent of protein; and Patna rice, which shows indications of severe 
milling, also has a high protein content. The climatic and, possibly, 
the soil conditions under which rice is grown seem to exert as great 
an influence upon the quantity of its protein as does the method or 
severity of milling. By comparing the protein content of the first 
with that of the second subdivision of the Japan rice type, as shown 
in Table III, it is seen that only 0.64 per cent of this constituent is 
scoured off in the process of milling. Even though the milling of 
rice does not remove the major part of its protein, as is commonly 
supposed, there is in the milling of a given quantity of the grain a 
total loss of this expensive food constituent which should be con- 
sidered. Completely milled rice can not be regarded as a balanced 
ration, simply because a large part of the original protein remains in 
the starchy endosperm of the kernel after milling. In judging a food 
the protein content is, of course, an important factor, but it must be 
considered in connection with various other important factors, such 
as ether extract and, to a less extent, ash. As previously mentioned, 
the milling of rice reduces its ash content very materially, and the 
ether extract, the greater part of which is in the germ of the kernel, 
is decreased from over 2 per cent to about 0.2 or 0.3 per cent, which 
is almost a negligible quantity. The slight losses in protein and in 
minute quantities of a substance called "vitamine," together with 
the very great loss in ether extract and ash, which result from the 
modern methods of milling rice, tend to greatly lessen its food value 
and to yield by-products containing large quantities of valuable 
constituents of human food. 
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