I 



DIGESTIBILITY OF SOY-BEAN AND PEANUT FLOURS. 9 



phane was the first limiting factor and lysine the second when all 

 other factors known to be essential to the dietary have been supplied. 



The nutritive value of the principal protein of wheat, gliadin, has 

 also been carefully studied. Osborne and MendeP found that "in 

 order to promote the growth of experimental animals it is necessary 

 to supplement gliadin with lysine." 



Hart and McCollum ^ report "It is evident that the whole-wheat 

 grain will not sustain growth and even leads to physiological disturb- 

 ances when continued as the sole source of nutrients for but a short 

 span of the entire period of growth." In a later paper Hart, McCol- 

 lum, Steenbock, and Humphrey ^ conclude that an exclusive diet of 

 wheat grain and wheat straw is wholly inadequate with heifers for 

 reproduction and in some instances for continued growth. 



The proteins of rye, rice, and barley ha v^e received much less atten- 

 tion by investgators than those of wheat and corn. It appears that 

 while rice and barley supply small amounts of total protein, orzinin 

 and hordein supply relatively large amounts of lysine. Osborne, 

 Van Slyke, Leavenworth, and Vinograd * in comparing the basic sub- 

 stances yielded by the proteins of the endosperm of wheat (lysine 1.58), 

 maize (lysine 0.97), and rice (lysine 4.26) with the figures reported by 

 Thomas ^ for the percentage of assimilable nitrogen 40 per cent, 29 

 per cent, and 88 per cent, respectively, say "It is rather striking that 

 the figures for the utiliz ability of these proteins correspond so closely 

 with the lysine which they yield." 



Buckner, NoUau, and Kastle ^ in experiments with chickens in- 

 cluded a diet in which both barley and rice were fed in conjimction 

 with hominy, oats, and gluten, and were of the opinion that the 

 unsatisfactory growth which resulted could be attributed to the low 

 lysine content of the diet, which probably means that only small 

 quantities of rice were eaten. Osborne and Mendel report feeding 

 experiments with rats in which concentrated oat, rice, and barley 

 proteins were added to an otherwise adequate diet. They state '^ that 

 " the total proteins of rice and barley in contrast with maize and oats, 

 when furnished in diets containing 16 to 17 per cent of protein, 

 supply enough of all the amino acids essential for growth." 



It is interesting to compare these conclusions regarding the value 

 of the cereal proteins with the conclusions reported regardiQg the 

 value of soy-bean and peanut proteins. In a study of the relative 

 value of some common proteins as supplements to corn gluten Os- 



1 Jour. Biol. Chem., 17 (1914), No. 3, pp. 325-349, figs. 8. 



» Jour. Biol. Chem., 19 (1914), No. 3, p. 276. 



» Loc. cit. 



< Jour. Biol. Chem.,. 22 (1915), No. 2, p. 276. 



6 Arch. Anat. u. Physiol., Physiol. Abt., 1909, pp. 257, 259, 261, 



« Amer. Jour. Physiol., 39 (1916), No. 2, pp. 162-171, 



' Jour. Biol. Chem., 34 (1918), No. 3, p. 531, 



64347°— 1§— Bull, 717 2 



