Evening star., 1939-04-11
Of Stors, Men
And Atoms
Notebook of Science Progress
In Field, Laboratory
And Study
By Thomas e. Henri.

By Thomas e. Henry.
Corn on the cob was upheld as food
for he-men and white bread, sometimes
denounced as the luxury of an effete
civilization, got high nutritive rating
from studies reported before the Ameri-
can Chemical Society at its recent meet
ing in Baltimore.
Drs. D. Rreese Jones and j. P. Divine
of the Department of Agriculture's
Bureau of Chemistry and Soils told of
using rats as test tubes for measuring
the food value of corn and finding that
it was much higher than generally is
recognized.
On straight corn diet except for
addition Of minute amounts of the nee
essary minerals and vitamins, they said,
their rats grew at normal rate and
developed into healthy, well nourished,
mature animals. The difficulty in the
past, they said, has been in evaluating
the proteins in corn, the food substances
that make blood and muscle. 1t has
been taken for granted that these were
of low nutritional value.
Most of the feeding experiments in
the past, they said, have not been con-
Quoted with the whole corn kernel, but
only with one or two of its isolated pro-
teins. The vitamins and minerals now
known to be essential to both mice and
men were not added in requisite
amounts. Another trouble, they said,
has been due to analyses of single pro-
tein, zein, which constitutes about half
of all the protein material in the grain.
1t is notoriously poor in nutritive quail
ties, but these are supplied by the COM
plex of proteins which make up the
other half
In their own experiments the rats
were fed freshly ground kernels con-
tanning all the proteins. Besides each
rat was given by means of syringe
each day about two drops OF solu-
ton containing the vitamins and miner
ais necessary to growth.
While admittedly rats are not men,
feeding experiments with these animals
generally yield data applicable to hui
man diets, they said. and there is no
reason why the results with corn should
prove an exception. They believe that
it should have much bigger place IN
the family diet
Both corn and white wheat flour got
ribbons in the experiments reported by
Drs. G. S. Traps and E. c. Carlyle OF
the Texas Agricultural and Mechanical
College They used live chickens IN
stead of rats for their test tubes.
The usual method of comparing
energy values of foods, they said, has been
by estimating their digestible content
of proteins, carbohydrates and 1at-the
three basic ingredients of life. 1t has
been assumed that the proteins and
carbohydrates have equal value and the
fats more than two times as much,
weight for weight.
Their method was to measure the
actual utilization of the elements by the
chickens by determining the gains o1
protein and fat in specific periods. One
lot of baby chicks was fed on a ration
containing corn meal, natural chicken
food, Three other lots were fed similar
ration in which so per cent was flour
wheat bran or wheat grey shorts. After
21 davs the chicks were killed and
analyzed and the gains found by deduct-
ing what they had started with, as
determined from analysis of some from
the same broods killed at the beginning
of the experiment.
1--WE were surprised to find" they re-
ported, that the chicks secured only %
per cent as much energy from flour as
from corn meal, only 3 per cent as mucn
from wheat grey shorts, and that wheat
bran caused an actual loss of energy
The relative values Of the digestiblc
constituents was in approximately the
same order.
This should indicate that the 10
per cent of flour secured in milling con-
tains practically all the energy value Of
wheat, certainly as far as chicks are
concerned and perhaps for humans.
The present practice of taking out the
flour for table use and feeding the bran
and shorts to mich cows or other ami
mails which can utilize it appears to be-
a better way for utilizing the energy
of the wheat than making whole-wheat
flour"
This conclusion, they stressed, applies
only to the amounts of energy gotten
out of foods They serve other purposes
for which they we're not measured in
these experiments. The work also indi-
Gates, DR.. Traps reported, that relative
energy values now assigned to foods OF
both humans and chickens may be badly
off since they are based on the assump-
ton that the digestible nutrients of one
food have the same value as similar
amounts in other foods.
Although chickens are different from
humans" he said, "and may utilize
digested foods differently, the work at
least indicates that there may be much
greater differences in energy values of
human foods than now are considered
to be the case and it indicates the
necessity of comprehensive investiga-
tions of the energy values of human
foods"