June i6,1923 
Nutritive Value of Protein Mixtures 
973 
Decreasing the protein level to 7.2 per cent, but keeping the proportion 
of tomato-seed press cake to com the same, resulted in a rate of growth 
somewhat below the normal. This was better, however, than the diet 
in which com alone was used to furnish the same amount of protein. 
An average gain in weight of 0.94 gm. per gram of protein intake 
was obtained during an ii-week period on this mixture. With the 
com alone, an average gain of only 0.73 gm. was secured. The low level 
of the protein intake was responsible for a rate of growth somewhat 
below normal. By using a diet somewhat below the minimum require¬ 
ment of protein for normal growth, the maximum gain in weight per 
gram of protein intake is obtained. Such a diet affords a better basis 
for a comparative study of the growth-promoting value of different 
proteins. 
EXPERIMENTS WITH CORN AND COCONUT PRESS CAKE 
Diets in which the proteins were obtained from mixtures of equal 
parts of coconut meal and whole yellow com enabled albino rats to 
Chart 2.—The plain continuous lines represent the rate of growth of rats on diet i, containing 5.4 per cent 
of protein from com, supplemented with 7.4 per cent of protein from tomato-seed press cake; the growth 
represented by the continuous dotted lines was made on diet 2, of which 3.1 per cent of the proteins came 
from corn, and 4.1 per cent from tomato-seed press cake, 
grow at the normal rate. On such a diet, the coconut meal furnished 8.4 
and the com 3.6 per cent protein, respectively. This experiment shows 
that the coconut proteins supplement ‘corn proteins, since better than 
normal growth was obtained with 12 per cent of the mixture of proteins, 
while 13.1 per cent of coconut proteins alone, in an otherwise adequate 
diet, just barely sufficed for normal growth (7). When coconut meal 
furnished 4.2 per cent and com 5.4 per cent protein in the diet, growth 
was somewhat subnormal. The coconut meal used in these diets was 
made both by the expression process (A) and by the solvent process (B). 
The processes seemed to be of equal value as regards the nutritive prop¬ 
erties of the meal produced. The results of this experiment are recorded 
in Chart 3. The efficiency of a coconut-com protein mixture for pro¬ 
moting growth, as shown by these experiments, is in agreement with 
the results reported by Maynard and Fronda (ii), who found that 
“ a mixture of com meal protein and coconut-oil-meal protein was of 
