MGESTlBrtll^Y OP SOY-BEAN AND PEANUT FLOURS. 7 



the nature and nutritive value of proteins, especial attention being 

 given to the amino acids supplied. While it was found that under 

 some conditions tyrosine, cystine, arginine, histidine, glutamic and 

 aspartic acids may act as limiting factors in the diet, it seems to be 

 very generally recognized by these students of nutrition that the two 

 amino acids, lysine and tryptophane, are of especial importance in 

 the dietary, lysine being essential for '^ growth" and tryptophane 

 essential for ''maintenance." In view of these conclusions it ap- 

 pears desirable to compare the amino acids resulting from the hydroly- 

 sis of soy-bean and peanut proteins with those obtained by the hy- 

 drolysis of the common cereal proteins. The amounts of amino acids 

 resulting from the hydrolysis of the principal proteins of some com- 

 mon cereals are brought together in the following table for comparison 

 with those obtained by hydrolyzing glycinin and arachin: 



Amino acids resulting from hydrolysis of proteins of cereals. 



Amino acids. 



Glycine . 

 Alanine. 



Valine. 



Lueeine 



Proline 



Phenylalanine - 

 Aspartic acid . . 



Glutamic acid . 

 Serine 



Tyrosine. 

 Cystiae. . 



Arginine 



Histidine 



Lysine 



Ammonia 



Tryptophane . 



Gliadin, 

 wheat. 



10.00 

 12.00 



13.34 



16.62 



1 13. 22 



12.35 



1.58 



1 43. 66 

 1 .13 



1 1.20 

 1 .45 



13.16 



2 2.19 

 2 1.21 

 15.22 

 1 1.00 



Zein,3 

 corn. 



0.00 

 9.79 



1.88 



19.55 

 9.04 

 6.55 

 1.71 



26.17 

 1.02 



3.55 



1.55 

 .82 

 .00 



3.64 

 .00 



Rye,* 

 prolamin. 



0.13 

 1.33 



Not iso- 



.lated. 



6.30 



9.82 



2.70 



.25 



38.05 

 .06 



1.19 

 Not esti- 

 mated, 

 2.22 

 .39 

 .00 

 5.11 

 Present. 



Oryzinin, 

 rice. 



6(?) 



6 3.7 



H?) 



6 14.3 



■63.3 



6 2.0 



6.4 



6 14.5 



6.5 



6 1.26 



6 9.15 

 6 3.32 

 6 4.26 

 6 3.23 



Hordein,' 

 barley. 



0.00 

 .43 



.13 



5.67 

 13.73 

 5.03 

 Not iso- 

 lated. 

 43.20 

 Not iso- 

 lated. 

 1.67 

 Not esti- 

 mated. 

 2.16 

 1.28 

 .00 

 4.87 

 Present. 



Glycinin.s 

 soybean 



0.97 

 Not iso- 

 lated. 



8.45 

 3.78 

 3.S6 

 3. 89 



19.46 

 Not iso- 

 lated. 

 1.86 



5.12 

 1.39 

 2.71 

 2.56 

 Present. 



Arachin,9 

 peanut. 



0.00 

 4.11 



1.13 



3.88 

 1.37 

 2.60 

 5.25 



16.69 

 Not iso- 

 lated. 

 5.50 

 .85 



13.51 



1.88 



4.98 



2.03 



Present. 



1 Jour. Biol. Chem., 9 (1911), No. 5, p. 426. 



2 Jour. Biol. Chem., 22 (1915), No. 2, p. 261. 



3 Amer. Jour. Physiol., 26 (1910), No. 4, p. 304. 



* Osborne, Ergeb. Physiol., 10 (1910), p. 86. (In the absence of a name for rye protein, Osborne referred 

 to the alcohol soluble protein as rye prolamin.) 

 6 Osborne, Ergeb. Physiol., 10 (1910), p. 112. 

 6 Jour. Biol. Chem., 22 (1915), No. 2, p. 275. 

 ' Osborne, Ergeb. Physiol., 10 (1910), p. 90 



8 Osborne, Ergeb. Physiol., 10 (1910), p. 132. 



9 C. O. Johns and D. B. Jones. To be published in the Journal of Biological Chemistry, 



It will be noted on referring to the above table that the earlier 

 analyses of gliadin, zein, rye-prolamin, oryzinin, and hordein indi- 

 cated that these proteins supplied little if any lysine and tryptophane. 

 In the more recent studies of oryzinin and gliadin it was found that 

 on hydrolysis these proteins yield appreciable amounts of lysine. An 

 unpublished investigation by C. O. Johns and A. J. Finks, Bureau of 

 Chemistry, shows that hordein on hydrolysis yields approximately the 



