14 BULLETIN 570, U. S. DEPARTMENT OF AGRICULTURE. 
The yield of finished rice of all grades varied from 64 per cent for lot 
D to 68.9 per cent for lot B, showing, as would be expected, that a 
high yield of rice corresponds to a low yield of by-products. The 
percentage of the bran coat taken off at the four stages varied greatly. 
It would seem that more satisfactory milling results might be ob- 
tained if it were possible to make the reduction at each stage* more 
nearly uniform. 
The chemical results given in Tables 8, 10, 12, and 14 show many 
interesting features. The moisture of the rough rice is seen to be 
mainly in the kernel, as the moisture of the hull in all cases was 
markedly less than that of the other samples. A lower moisture 
content was found in the several by-products than in the rice itself. 
This may be due in part to the interior of the kernel having a higher 
moisture content than the exterior portions, but probably is due 
mainly to the drying of the by-products by the heat developed in 
the milling process. This theory is supported by the fact that the 
polish is of lower moisture content than are the brans. 
The ash in the stone-reel bran from the four lots of rice milled ap- 
proximated 15 per cent, showing the presence of hulls in this bran. 
This also is shown markedly by the ash insoluble in hydrochloric acid, 
which averaged about 11 per cent, as compared with about 1 per 
cent for the huller brans and polish. Lot C, composed of Japan-type 
rice, was the only lot that showed a high insoluble ash in the first- 
break huller bran. This is accounted for probably by the fact that 
the small grains of rice of the Japan type do not separate so well in 
the paddy machine as do other types of rice. 
A marked tendency for the ether extract to exceed protein was 
observed in all brans, particularly in those from Blue Rose rice, which, 
in general, are higher in ether extract than, and have approximately 
the same amount of protein as, brans from the other types of rice. 
The relation of ether extract to protein gives some indication as to 
the addition of hulls, since hulls contain considerably more protein 
than ether extract, and their addition to the bran tends to bring the 
determinations for these two constituents more closely together than 
would be the case if the bran were free from hulls. This has been 
observed in the case of so-called 20 per cent brans, which have 
been standardized to 20 per cent fat plus protein by the addition of 
hulls. The trade custom of rating rice bran on the basis of the fat 
plus protein content is of long standing. 
The percentage of crude fiber decreased markedly as the reduction 
process was continued. The high figures for stone-reel bran are, of 
course, due to the presence of hulls. The determinations of pentosans 
and starch made on samples of lot A appear to furnish no information 
regarding the products not given by the other figures, 
