No. 6. DEPARTMENT OF AGlllCl 'I/riTKlv 59!) 



Graius dried at a low temperature in vacuum, 79.6 — 84.1 



Grains dried in ordinary kilns, 67.8 — 73.6 



Grains dried bj' flue gases, 58.3 — 59.0 



The fat of dried brewers' grains has been little studied. Dietrich 

 found in mixed grains from various sources a brown fat,* showing 

 the following characters: 



Per cent. 



Free fatty acids reckoned as oleic acid, 32.7 



Neutral fat, 56.2 



Lecithin, 6.3 



Unsaponifiable matter (cholesterin), 4.8 



The total lecithin content of the grains was 1.48 per cent, of the 

 dry matter. The free fatty acids, calculated as oleic acid, on the 

 basis of 72 analyses, range from 12.7 to 57.4 per cent, of the total 

 fat, and average 83.1 per cent. That is, as a comparison with the 

 composition of the fat of the original barley quickly shows, the 

 proportion of neutral fats is greatl}^ reduced and that of free fatty 

 acids correspondingly increased, in the course of the malting, mash- 

 ing and drying of the grains. 



The nitrogen free extract composes nearly one-half of the dried 

 grains. It is made up chiefly of more or less modified starch that 

 has failed of complete inversion, gums and dextrins. There is very 

 little unmodified starch remaining. 



The grains contain, partly in the nitrogeu-free extract, partly 

 in the crude fiber, from 22 to 30 per cent, of pentosans. Tollens 

 and Glaubitz found that of the constituents in the malt, three- 

 fourth reappear in the dried brewers' grains; they further found 

 that, in a sample yielding 26.48 per cent., 22.76 per cent, was readily 

 attacked by dilute acid and 1.20 per cent, by dilute alkali, leaving 

 only 2.-52 per cent, in the crude fiber; so that over 90 per cent, of 

 the entire amount appears in the nitrogen-free extract. When acted 

 upon by acid, the chief product is xylose — the characteristic pentose 

 sugar yielded by bran, corn cobs, etc. — though some arabinose is 

 also obtained. 



The a^h of the brewers' grains usually contains from 0.5 to 

 0.75 per cent., rarely 1.0 per cent, of sand or other foreign mineral 

 matter. On the average, one ton of the grains contains of the 

 more important mineral matters: 



Pounds. 



Potash. 2.6 



Phosphoric acid, , 29.6 



Lime, 96 



*The fat had an iodin number of 93.6: saponification number, 195; refractive degree at 40 de- 

 grees C, 66. 



