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THS.

THE CALORIC AND PROTEIN VALUES
OF SOME COMMQNLY EATEN

FOOD MIXTURES AS DETERMINED
BY DIRECT ANALYSIS

Thai: for fin Degree of M. S.
MICI'IIGAN STATE COLLEGE
Virginia Rufh W055“

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THE CALORIC AND PROTEIN VALUES
on

son COMMONLY EATEN FOOD MIXTURES
A8 “

DETERMINED BY DIRECT ANALYSIS

_ 31
Virginia Ruth Weller
“-—

A THESIS
Submitted to the School of Graduate Studies o£.M1eh1gen
State College of Agriculture and Applied Science
In partial fulfillment of the requirements
for the degree of
Master of Science

Department of Foods and Nutrition
School of Home Economics

1949

ACKNOHLEDGMENT

\

,/

To Dr. Edna Brown for her encouragement;
helpful suggestions; and advice during the course
of this study. the author wishes to expreaa her
sincere appreciation. Acknowledgment is also.
made to Assistant Professor D. D. McGrady and
others of the chemical and Metallurgical
Engineering Department for their valuable assist.

ance and for the use or a bomb calorimeter.

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TABLE or CONTENTS

Page
I.INTRODUCTION..............1
II. REVIEW OF LITERATURE . . . . . . . . . . 5
III. EXPERIMENTAL PROCEDURE . . . . . . . . . 21
IV. RESULTS AND DISCUSSION . . . . . . . . . 23
V. SUMMARY AND CONCLUSIONS . . . . . . . . 35
VI. LITERATURE CITED . . . . . . . . . . . . 38
VII AI’PENDIX................41
A. Details of’Procedure Used in Preparing
Dried Samples or'Hamburger} Bun, Chocolate
malted Milk. and Chili hon Garne.

Bo Tables IV and V

II.

III.

IV;

V.

LIST OF TABLES
Table Page

Fuel Values of Hambur er; Bun. Chili Con
earns. and ch00°13t9 lted Milka o o o o o 233

Physiological Euel Values of Hamburger.
Bun. chili Con Carne, and Chocolate .
Halted Milk. 0 o o o o o o o e e o e o o o . 84a

Nitrogen and Calculated Protein Content
of Hamburger, Bun, Chili Con Carne, and
chOCOIQtO malted Milk. 0 o o o o o e e o o o 28‘.

Recovery of Nitrogen from a Standard
solutian o o o o o o o o o o o o o e o o o o 44

Determination of Water Standard for
Calorimeter Using Bensoio Acid . . . . . . . 44

I. INTRODUCTION

Endeavors throughout time have been directed toward
improving man's life situation in relation to health. Man
has attempted to find the best environmental conditions in
which to live} and in order to do that he has attempted to
uncover the facts about the composition of the material
things of which his surroundings are composed. He attempts
to supply the body with what it requires through the proper
use of food. And. it has been important to ascertain the
composition of the human body in order to help determine its
requirements. Only through the knowledge of the compositien
of the foods consumed by humans can the nutritionist. the
dietitian. those in the medical profession; the welfare
worker} and the teacher instruct others in.choosing the foods
which.will encourage optimal nutritional status for individ-

uals as well as for populations.
. "

For this reason. food composition has been studied by
many persons. During the first half of the nineteenth century
work.in the field of food analysis was sporadic. Later in the
century. Diebig's develOpment of knowledge and methods of
organic chemistry made it possible for more systematic investi-

gations of the composition of food materials. In 1872} when
Atwater returned from study of agricultural scientific

-2-

advancement in Germany. he was convinced that the peeple of
the United States had a need for more information about
food composition. The available tables had been compiled
for foods consumed by Germans. and they were not applicable
in many instances to foods consumed in America. And so; it
was through Atwater's efforts that the first extensive
compilation of’American foods was prepared. This work was
published by the United States Department of Agriculture
as Office of'Esperiment Stations Bulletin 88 under the title.
"The Chemical Composition of American rood Materials".
although the 4;OOO analyses of American food materials
included in this table proved to be extremely useful to
professional peeple in the fields of’nutrition and medicine;
Atwater realized that these tables would have to be revised
at some future date. He states this in the first publication
and the 1899 revision of the U. 3. D..A. Bulletin 28:
This table is intended to replace previous ones}

and to serve as a standard for reference until it

shall. in its turn. be replaced by a larger and more

complete compilation. ’

{Additional analyses continued to be made on foods which
Atwater had not included. Through the efforts of Chatfield
and.Adams the "Proximate Composition of American Food
Materials" waspublished as U. 8. D. A. Circular No. 549 in
1940. This table contained some of Atwater's results as well
as the results of’many other investigations in an attempt to
provide a more complete table to supplant Atwater's Bulletin

28. Advancement in research concerning vitamin and mineral

values provided more information about the composition of
foods which we find incorporated in a newer food table.
‘the U. 8. D. A. Miscellaneous Publication No. 578. "Tables
ef’Pood Values in Terms of Eleven.Nutrients'.

Almost all of the workers in this field since Atwater
included the figures from his analyses in their tables.
However. for convenience the information was presented in
several different ways. For example. some authors expressed
nutritive values per pound. others. per gram of each food
product. Comparison of the value of foods with recommended
allowances was develOped into a share system of food values

by Mary Swarts Bose.

B.

In our society today. we have become accustomed to
cafeterias. diners. and places where I'short orders” are
served. it these places food mixtures are sold and many of
them.have become a part of the normal diet and are accepted
as standard items. With (the ever increasing number of
persons eating all their meals. or at least one meal of the
day. "out" because of the business stress of today's society}
there is a need to know the common restaurant practice for
the preparation of these items. As this situation developed
over the years. it became increasingly apparent that the
nutritive values for food mixtures were desirable for
convenience in calculating diets of today. In some food

tables the authors have used a recipe method. in which the

-4-

value of each.ingredient was known and the total value of
the ingredients was taken as the nutritive value of the
food mixture. Ellen H. Richards was among the first
workers to set up a table of food values fer food mixtures
calculated from recipes.

Benedict and Farr working at the New Hampshire
Agricultural Experiment Station analyzed some food mixtures
commonly eaten in a college community. Food mixtures such
as sandwiches. cookies. candy bars. many flavors of ice
cream. and pics of various kinds were analyzed.for energy value
and protein content. The results of this work were published
in 1929. Although this work is quite complete in its cover-
age of foods eaten by the students. some pcpular items were
not included. A hamburger on a bun. a malted milk are common
items today which were not among the foods analyzed by
Benedict and Farr.

It was the purpose of this study to determine the energy
value and protein content of certain popular food mixtures
as served to patrons in the cafeterias and drugstores in a
college community. This study is limited to laboratory
analyses of commercial servings of foods for which there is
little information in the literature: a hamburger on a bun.

a malted milk. and a bowl of chili con carne.

II. REVIEN OF LITERATURE

Until 1896 tables of food values were concerned with
foods consumed by EurOpeans; particularly Germans} for the
work up until that time had been done in EurOpean and
German laboratories. In America we had no such tables for
American foods and we were forced to rely upon such works
as those compilations of food materials generally consumed
by the Germans. Atwater. having seen the workings of the
German organization for scientific study of German
agriculture. became increasingly interested in develOping
agricultural science in the United States. particularly
in the field of food composition.

One of the beneficial outcomes of Atwater's endeavors
was Bulletin 28. This bulletin was comprised of many
investigations carried on both at the Storrs. Connecticut
Agricultural Experiment Station and at other laboratories
and experiment stations in the country. It included
compilations of analyses made by Professor Atwater and his
associates. by the Division of Chemistry of the U. S. D. it:
and by other investigations and miscellaneous sources. It
was from collating all this scattered information that the
results of 4.006 analyses were recorded in tabular form to
make up the "Chemical Composition of American Food
Materials". ~

4‘

The figures recorded for the nutritive values of foods
cannot be taken as accurate. indisputable facts. In bulletin
28. the maximum and minimum values of the composition of
American food materials were recorded as well as the average
values. Atwater and his cc-workers had collected more than
one value for almost all of the foods included in the tables.
However. little mention was made in subsequent tables of the
maximum and minimum values. There were differences in the
values obtained because each food as it is grown has
inherent differences from another supposedly Just like it.
and also. because the accuracy of the figures as recorded
are dependent upon man's technical skill used in making the
analyses.

Little additional work was done to improve upon or.
increase the information grouped together by Atwater. However.
as investigations in vitamin and mineral content of foods in-
creased. some of the results were tabulated and added to the
information provided.in Bulletin 28.

For additional information concerning the proximate
principles Chatfield and McLaughlin (1923) and Chatfield and
Adams (1951) compiled original data on the proximate composi-
tion of fruits and vegetables which were tabulated into new
summary tables. In 1940 a similar table for all foods was
published and this work. WProximate Composition of American
Food Materials". by Chatfield and Adams. included the inferma-
ticn in the tables by Chatfield which were Just mentioned.

The table most recent in development. as far as
expansion and revision of Atwater's data is concerned. is
the U. 8. D. A. Misc. Bubl. No. 572. ”Tables of Food
Composition in Terms of Eleven Nutrients“. It includes
not only the proximate principles. but also vitamin and
mineral values for food materials. Blvehjem (1946) has
recorded a brief history of the evolution of this table.
He states that in 1942 the Food and.Nutrition Board was
requested by the Office of the Quartermaster General to
establish a committee to "assemble. coordinate} and appraise
data on food composition for the War Department'. A committee
on Food Composition undertook the first problem of compiling
a table listing the proximate. mineral. and vitamin values of
some 250 foods. and hence. made use of information l"... frmm
data reported in the literature and in part from unpublished
data made available through many sources"... (U. 8. D. A..
Misc. Publ.. No. 672). Information adding to current know-

ledge was provided “... from the research of the State agri-

A

cultural experiment stations and from Federal. commercial.
and other laboratories that have carried out analyses through
special arrangements with the National Research Council'

(U. S. D. M. Misc. Publ. No. 572). This table is relatively

complete; but it contains few cocked foods or food mixtures.

Since the publication of Bulletin 28. many tables of
food composition have been published and are in use. There
are tables by:

Richards - The Dietary Computer
Locke - Food Values
Bose - A Laboratory Handbook for Dietetics
Bowes and Church - Food Values of Portions
Commonly Used
Bridges - Food and Beverage Analysis
Taylor - Food Values in Shares and Weights
Bradley - Tables of Food Values
Donelson.& Leichsenring - Food Composition
Table for Short Method of Dietary
Analysis
Boyd. Bade. Sandstead - Food Value Tables for
Calculation of Diet Records
and also tables found in the Appendices of textbooks on
foods and nutrition by such authors as Bcgert. Pattee.
Bose. and Sherman. I

These tables either in part or in entirety are depend-
ent upon values from the following three compilations of
original data:

Atwater - Chemical Composition of’American Food
Materials. U. 3. D.".. 0. E. 3..
Bulletin 28. 1896 (Rev. 1999 and i906)

Chatfield and Adams - Proximate Composition of

American Food Materials. U. 3. D. A.
Circular No. 549. June 1940.

Bureau of Human Nutrition and Home Economics -
Tables of Food Composition in Terms of
Eleven Nutrients . U. S. D. A. Rise.
Publ. No. 572.

From these listings it can be seen that a very few
compilations of original data are the references and
standards for many tables of food values used for general
public and professional use.

The tables mentioned above are mainly concerned with
single foods or food mixtures whose values have been
calculated from the ingredients. Direct analyses of food
mixtures have been made by few investigators.

(McCance and Widdowson (1940) working at the University
of’Cambridge determined food values for British foods. Food
mixtures were considered. The recipes for the various
dishes were chosen. the ingredients were weighed and mixed
tagether according to the directions. These muxtures were
weighed before cooking. and then again when they were ready
for consumption. Instead cf’analysing these prepared
mixtures. the food values were calculated from the composition
of the listed ingredients and the change in weight in cooking.
Only the fried foods were analysed.

Benedict and Farr (1929) in this country conducted re-
search over a period of two years to secure data regarding
the energy and the protein value (1) of several individual

foods} such as breads. pastry. soups. sandwiches. salads.

desserts. ice creams. and candies; (2) of the total meal -

1b- a... 91.

1'.

.a.\

an it...) it.

-10..

breakfast. dinner. and supper; and (3) of the total food
consumed per day by an individual. These workers chose '

to take their samples from three types of eating places;

the commercial restaurant. the college cafeteria. and the
drugstore. They referred to the foods such as candies and
ice creams as ”extra foods". The authors felt that the

use of these co-called "extra foods" was widespread in this
country. and that their results were representative of the
energy values of many of the present-day. somewhat standard-
ised food mixtures.

Fuel value is one of the measures made of foods. It is
referred to as heat of combustion. energy. or caloric value
of foods. Calorimetry is use a- and it has been defined
as "the theory and practice of making measurements of
quantities of heat” (Worthing. 1948). The unit of measure
is the large calorie. which is the amount of heat required
to raise one kilogram.of pure water one degree centigrade
when the pressure is one atmosphere} and temperature 15° 0.

Caloric values for food materials are obtained through
the use of two types of equipment. the cxy-calorimeter and
the bomb calorimeter. The latter instrument is used in
obtaining the physical caloric values of foods and constit-
uents of foods. The physical caloric values of the constit-
uents (protein. fat. and carbohydrate) were the basis of
both Bubner's and Atwater's calculations for the physio10gical

fuel value of foods.

-11-

Rubner's “standard values" have been widely used
throughout the world in determining the average fuel
value of a mixed diet. He reasoned that the heat value
of one gram of protein would be 4.1 calories in such a
diet. This figure is an average of the physiological
caloric values for the calculated protein content of a
mixed diet as follows: casein. 4.4. organic substances of
meat. 4.233} and vegetable proteins. 5.96. For the heat
value of fat in.a mixed diet Bubner considered 9.5 calories
per gram to be correct. He reckoned this from an average of
stohmsnnis caloric values for olive oil (9.384 oai./gm.);
animal fat (9.372 cal./gm.):". and butter fat (9.179 cal./gm.).
Heat values had been determined by Stchmann and Rubner for
various carbohydrates (dextrose. milk sugar. cane sugar. and
starch). Rubner felt that starch was of predominant import-
ance in the average diet. and. therefore. he assigned the
value of 4.1 to carbohydrate heat value in foods. (Luck.
1909). These values are best used if applied to a mixed diet.
(lkynard. 1944).

The "Atwater System". on which all studies made in the
United States since 1900 were based (Morey. 1956 - 3?).
involves consideration of losses in digestion. Atwater (1895)
also felt that we should consider the physiological value of
the diet rather than the physical. From 185 dietary studies
made on different peoples in different areaaof the United

States. Atwater summarized the data and classified the
foods consumed into various groups. For each group. such
as dairy products. cereals. legumes. etc.. he calculated
the percentage of protein. fat. and carbohydrate. The
average figures obtained"... were taken to represent the
relative proportions of total food and total nutrients
supplied by the different food groups in the 'average
diet'." (Maynard. 1944). He next determined the heats of
combustion of various proteins. fats. and carbohydrates.
From these data he averaged the values fer the different
groups and found the following findings:

Heat of Combustion

0; Tgtal Egg; pgr ggam
Protein 5.65
Fat 9.40
Carbohydrate 4.15

Prom.the summarized data of 97 digestion experiments with
mixed diets and of others with single foodstuffs} Atwater
arrived "at the average coefficients of availability
(digestibility) for the nutrients of the different food
groups and for the average mixed diet. ...'. (Maynard; 1944).
The figures were listed as the Proportion of Total Nutrient
Actually Available: protein. 92; fats. 95; and carbohydrates
97.(Btorrs. Connecticut Agri. Exper. 8ta.. 1899). The product
of the latter figures and the respective heats of combustion
per gram gives the total energy available per gram of

nutrient. In the case of protein. Atwater found 1.25 calories

-13-

per gram of protein was lost in urea and. therefore.
should be subtracted from the product. Atwater finally
”... arrived at the overall{§alorio]values we now use.
namely: protein 4. fat 9 (rounded off from 8.9) and
carbohydrates 4' (Maynard. 1944).

Maynard (1944) makes a noteworthy statement in regard
to the use of the Atwater system:

It should be noted that the Atwater factors.

4-9-4. as arrived at by the procedure indicated in

the table. apply stricly only to the diets in'

which the kinds and preportions of foods are similar

to those of his averaged mixed diet.

Also issuing this same precaution was the FAQ Committee on
.Caloric Conversion Factors and Food Composition Tables who.
in 1947. said they could find no evidence that Atwater's
data. preperly used. were not reliable. Merrill and Watts
(1948) discussed the use of this system in their paper on
the 'Physiologio Energy Value of "heat“.

(In reviewing the methods used to obtain energy values.
mention was made above of the oxyccalorimeter and the bomb
calorimeter. Benedict (1929) was one of the more important
workers using the former piece of equipment. He believed
the use of it was a I'simple technique" than making chemical
, analyses of foods. or Operating a bomb calorimeter.

Morey (1956 - 37) in referring to work done by
Benedict. points out that the values obtained by him with the

oxy-calorimeter. were very similar to those which might be

obtained if Bubner's factors had been used. since the oxygen

-14-

used in the calculation has already been corrected for
physiological losses.

The bomb calorimeter is another instrument long in
use for energy value determinations. Concerning the use
of it. Sherman (1944) says: "As the result of years of
most painstaking research it was found: ... that with the
bomb calorimeter the energy or fuel values of foods can be
measured with great precisions...". Since the bomb
1. considered .h accurate. it seems to be one of the best
pieces of eqiupment to use in determining the fuel value of
single foods and food mixtures.

All protein values found in food composition tables to
date are calculated from the nitrogen content of food. which
has been determined through the use of some variation of the
Kjeldahl method. (Atkinson in 1893 refers to "... the
principal nutrients - nitrOgen. starch. and mm. which
seems to be a more accurate way of referring to the composition
of food.msteria1s. in respect to protein at least. The nitrogen
content is determined by analysis. whereas. the protein value
is calculated by applying a factor to the nitrogen value.

The need for accurate protein conversion factors has been
- recognized for many years. Atwater used the factor 6.25 in
obtaining the protein value of almost all the foods included
in his food composition table. In the Twelfth Annual Report
of the Storrs. Gonnecticut Agricultural Experiment Station;

Atwater makes it clear that there are varying percentages of

nitrogen in certain proteins. However. he believed that
the factor 6.25 covered all common animal foods. including
milk.

This way of calculating protein values depends on two
assumptions. neither of which are wholly correct. One is
that all nitrogen in food materials is in the form of
protein nitrogen. There are some nitrOgencus substances
in food materials which are not proteins. nor related to
proteins. The second fallacicus assumption is that all
proteins contain 18 percent nitrogen. The proteins of
cereal grains and milk have been feund to contain different
percentages of nitrogen than the proteins of meat and eggs.
Wheat flour,for example; is.made from the endosperm of the
wheat kernel. It is used in the making of bread and rolls.
The principal proteins of the endosperm.are gliadin and
glutenin. Gliadin contains 17.6 percent nitrogen. and
glutenin. 17.5 percent nitrogen. For an average we find the
endosperm protein contains 17.55 percent nitrogen which gives
the factor 5.7 (100 .7 17.55 g 5.698 or 5.7). Most of the
proteins isolated from meat and eggs contain 16 percent
nitrogen. so that the factor 6.25 seems to be reasonable for
calculating the protein content of foods of animal tissue.
The factor 6.38 for calculating the protein content of’milk
has been in general use for some time. The principér

proteins of milk are casein and lactalbumin and an average of

-15-

the percent nitrogen in each of these two proteins is
15.66 percent producing the factor 6.58.(Jcnes. 1941).

The use of these factors for their respective foods
should yield more accurate results in calculating the
protein content of these foods than the all-inclusive use
of 6.25. However. even though these factors help give us
more accurate results than an indiscriminate use of 6.26%
they are not perfect factors because available data are
not sufficiently complete to formulate such factors.

Up to this point there has been discussion of the
methods used in obtaining calorie and protein values in the
food composition tables. It has been seen that there are
certain limitations in accuracy placed on all figures
recorded in the tables. These limitations hinge on man's
technical skill and interpretation of data. 1

The foods we accept as common foods of our day and
which are included in this investigation are a hamburger
on a ban. a malted milk. and chili con carne. The first
mention cf any of these foods that we find in the food tables
is in 1917. At this time Locke published his book cfflgggg
1313§§,and among those listed is included malted milk whose
nutritive value as listed was obtained by totaling the value
of the ingredients. The next mention cf'any of these feeds
is of hamburg steak listed as "beef. broiled" in Rose's
_§aboratc£y_Handbook'fg£ Dietetics. 1929. Bridges lists chili

-17~

con carne in his "Table of Nutritive and Caloric Value of
Foods” published in 1955. The value of this food product
also was calculated from its ingredients. but the recipe
was not included in the reference. In 1942 two tables
were published. One by Bradley which included values for
chocolate malted milk. chili con earns. and hamburger: and
one by Taylor which included chocolate malted milk and
hamburger. whose values were calculated from the ingredients
of the recipe. Bowes and Church. in 1944} published their
M m 3; mm Commonly M which included values
for "chocolate malted milk shake“. The latest table).
published in 1947‘. by Boyd; Eads‘. and Sandstead included
nutritive values,calcu1ated from ingredients. for all three
food mixtures: malted milk. hamburger on bun. and chili
con carnee It is not knownfrom the information printed in
these tables how many recipes were used in obtaining the
Inutritive values. In some cases the ingredients of the
recipes used to obtain the food values are not published)
with the tables although they may be readily available on
request.

The recipes. which were printed with the tables. are
as follows: i

For Docke's figures: Melted Milk

1 heaping tbsp. malted milk
7/8 cup milk

-13-

For Bradley's figures:
Halted Milk

5/4 c. milk

2 T. chocolate sauce

1 T. malted milk

1/3 cup ice cream (2 small acceps)

Chili Con Oarne
1 can kidney beans
1 lb: ground beef
1 onion
1 to fat
1 c. cooked rice

For figures from Bowes and Church:

Chocolate Halted Milk.3hake
6 '7 8 0’s Milk
1 - 1 1/2 oz. chocolate syrup
2 as. ice cream
(from regulation soda fountain recipes)

-19-

The nutritive values of the foods as recorded in

the tables are summarized as follows:

assesses.

Maltedtflilk:
1 cup
1 1/2 Os
10 or. glass
10 oz. glass
1 cup

Hamburger:
2 1‘2" diam.:
7/6- thick
1 of a 1/4"X3"11/4"
1 cake. 2 5/4! diam.
7/8" thick -
1 hamburger and
bun (commercial)

Chili Con Carne:
1/2 cup
1/2 cup
1 cup

300
579
360

57

25
88

100
136

Fuel
Value
Calories
9.71 221
10.8 405
13.8 460
13.7 480
8.1 287
(55 cai. 100
from.protein)
8.5 140
20.7 150
11.5 228
13.3 115
17.7 275
21.1 366

Source of

Informatigg

Locke

Bradley

Taylor
Bowes a Church
Boyd. et 81.

Rose

Bradley
Taylor

Boyd. et a1.

Bridges
Bradley
Boyd. et a1.

Through the years there has been a paucity of‘informatien

gathered on these particular foods. and because of the various

methods used in calculating fuel and protein values.-there has

been divergence in the information as printed in different

tables of food composition.

III. EXPERIMENTAL PROCEDURE

A hamburger on a bun. a malted milk. and a serving of
chili con carne were purchased from five popular commercial
eating establishments in the East Lansing area. These
establishments are accustomed to selling orders to take out
and it was a simple matter to collect samples representative

of the foods as served to the general public.

Eggparatign 19; W. As each food mixture was

received in the laboratory. the total portion was weighed
and prepared for analysis. Each purchase was blended with
water in a Waring Blendor. With the exception of the malted
milks.the food mixtures were transferred quantitatively to
large glass trays in which they were air dried at room
temperature with the use of an electric fan. Then the foods
were ground to a fine homogeneous mixture. and weighed on a
torsion balance. Half the dried weight of each sample was
wrapped in cellophane (with a pharmaceutical wrap) and
stored in a dessicstor. This half of each dried sample was Set
aside and used later for the determination of caloric values.
The remaining half of each sample. for determining nitrogen

content. was stored in approximately 1 H hydrochloric acid.

The malted milk is a type of food mixture that is not
successfully dried in the same manner as the other foods
studied. Attempts to air dry it at room temperature produced
a gum-like consistency which was much too difficult to work
with. It was not possible to get all of this gummy substance
from the trays; nor was it possible to grind it to a homo-
geneous mixture. Therefore. each entire purchase of malted
milk in the fluid state was weighed and divided by weight
into two parts. Que half was acidified for nitrogen
determinations. and the other half was used for heat combustion
det ermi net i one .

The most suitable procedure to follow in preparing the
malted milk for combustion was that of drying weighed portions
of the material sufficiently for ignition. This was carried
out by drying the malted milk directly in the ignition pan of
the bomb calorimeter. (Detailed directions for the preparation
of dried samples of hamburger. hamburger bun. malted milk. and

chili con carne are included in the Appendix.)

Hgthgdg fl Analysig. 1. The caloric value (or heat

combustion) of each food mixture was determined in the
Emerson Fuel Calorimeter following the method described by
Mahin (1952) .

- 2. The protein values were
determined according to the macro-Kaeldahl method.

Three replications were made of each analysis.

IV. RESULTS AND DISCUSSION

(The average fuel value. as determined by the bomb
calorimeter uncorrected for physiological losses. was 115
calories for a hamburger. 179 calories for a bun. (making
a total of 294 calories for the combination)". 518 calories
for the malted milk. and 349 calories for chili con earns.
These values are expressed in.Tab1e 1.

However. plainly observable from the literature is the
fact that the physical fuel value of foods is higher than
the physiological fuel value of the human body. and it is
the available energy value of foods which concerrs us. It
was necessary. therefore. to calculate the physiological
fuel values. For the calculation of the values for the
foods in this study figures determined by Atwater are used
and we are dependent upon the accuracy and validity of his
work. From his experiments on availability and digestibility
of food materials in the human body. he found there were
varying coefficients of digestibility of protein. fat. and
carbohydrate. Fat and carbohydrate are believed to be
oxidised completely by the body, whereas. the protein is not.
Prom.the nitrogen found to be present in the excreted endp
products of digestion. it was calculated that 1.25 calories.
from every gram of protein ingested: were not utilized by the
human body.

 

 

FUEL VALUES 0? HAMBURGER, BUN, CHILI CON CARNE, AND CHOCOLATE MALTED MILK.
(Bomb Calorimeter Determinations Uncorrected for Physiological Losses)

Table 1 e

 

 

 

Food - Eating _ Fuel Value
Product Estab. Weight, A.P.* Food, Dry Food. A.P. per Serving
Grams Cal./gm. Cal./gm Calories
Melted A 298.1 1.59 474
Milk B 510.2 1.69 524'
C 276.7 1.84 510
D 514.4 1.51 411
E 551.5 2.05 675
AV. 506.2 1.69 518
s 0.75
Hamburger A 46.1 6.65 5.15 144
B 42.0 6.75 5.27 157
C 51.1 6.51 5.25 100
D 50.2 6.69 5.29 99
E 29.6 6.58 5.12 92
AV. 55.8 6.65 5.21 115
s 0.05
Bun A 49.5 4.70 5.49 170
‘ B 48.5 5.05 5.77 185
C 51.7 4.95 5.44 178
D 47.5 4.78 5.58 169
E 52.0 5.09 5.71 195
AVe " 49e8 4:091 5e60 1'79
-.. . s . 0.18
Chili A 264.0 5.60 1.50 343
B 572.2 4.87 0.90 557
' C 555.2 5.16 1.55 441
D 412.5 4.77 0.95 592
E 267.9 4.90 1.06 284
Av. 550.4 5.06 1.11 559
-9 0.20

* A. Purchased.

 

I
N
C»?
:32»

I

 

 

-24-

In this study the physical energy and protein values
were determined. Therefore, to calculate the physiological
caloric value. it was necessary to determine first the
physical fuel value from the protein (Table II, column 1)
and by difference obtain the number of calories provided
by the combined fat and carbohydrate of the food (Table II.
column 8). Atwater's correction factors may now be applied.
The physiological calories from protein are obtained by
applying the prOper factors to the known protein content of
the food (Table II. column 5). The physiological calories
from the combined fat and carbohydrate constituents are
calculated by the application of a known factor to the
physical calories per serving from these constituents
(Table II. column 4). By adding flgures in column 5 with
those in column 4, the total available calories per serving
of each food item are obtained. These values are shown in
column 5 of Table II.

The coefficient of digestibility for fat is 95% and
for carbohydrate is 97%. Since these are so similar. an
average of these two figures of 96% was used which precludes
the necessity for determining both of these constituents of
food materials. The application of 96% to the physical
calories provided by the fat and carbohydrates of the food
gives the total calories available or physiological fuel

‘value from these constituents.

 

Table II.

PHYSIOLOGICAL FUEL VALUES or HAMBURGER. BUN; CHILI CON CARNE, 4ND CHOCOLATE MALTED MILKl.

 

 

 

 

' . Ungorrected ‘5 - Available Fuel Value
Food Eating Weight Fuel Value from per
Product Estab. A. . Protein2 Fat and CHO Protein5 Fat and CEO Serving
Grams 08.1. 08.1. 08.1. Cale Cale
Malted A 298.1 74 400 56 584 440
M11k B 510.2 69 455 52 - 457 489
0 276.7 65 445 49 427 476
D 514.4 79 , ' 551 60 518 578
B 551.5 75 598 56 574. 651
' ‘ I
, Ar. 506.2 72 448 - 54 428 485 3
(Range from Literature - 221-480) 7
Hamburger A 46.1 67 78 50 74 125
B 42.0 62 75 47 72 119
C 51.1 46 54 55 52 87
D 50.2 45 54 54 52 86
E 29.6 46 46 , 55 44 79
‘ ' Av.~ 55.8 . 55 51 40 59 99
(Range from Literature 100-505)
Bun A 49.5 25 145 , 16 140 155
B 48.5 25 159 " 15 155 168
C 51.7 24 154 15 148 165
D 47.5 25 146 15 - 140 155
E 52.0 25 158 , 15 151 177
_ -A“ _ Av. 4§C8 24 155 15 148 184
Chill A 264.0 95' 250 61 240 501
B 572.2 '88 248 58 258 296
C 555.2 125 - 518 ‘ 81 505 ~ 586
D 412.5 116 276 ' 76 265 541
5 287.9 _ 87 197 57 189 248
, Av. 550.4 , 102 ‘ 258 57 248 514
(Range from Literature ' 115-5881

1 Galeulated by.Atwater's Method.

2 Obtained by multiplying protein grams per serving (Table III) by the factors:
5.65 for malted milk and hamburger. 5.80 for the bunfi and 5.68 for chili con carne.

Factors used to obtain available calories from protein: 4.25 for malted milk and
hamburger; 3.70 for the bun; and 5.73 for chili con carne.

 

 

 

-25-

The coefficient of digestibility of protein of meat
and dairy products if 97%. of cereais 85%. and of legumes
78% (Atwater and Bryant. 1899). For every gram of protein
from meat and dairy products Atwater found there were 5.65
physical calories; for every gram of cereal product 5.80
calories; and for legumes 5.70 calories. (It appears that
the average figure 5.68 might be used for chili since it is
a mixture of meat_and legumes.) The factors 5.65. 5.80.
and 5.68 are used to obtain the figures recorded in Column I
Table II. Now. the additional factor of 1.25 must be applied.
Therefore. to obtain the available energy value per gram of
protein. 1.25 is subtracted from the product of 5.65. 5.80.
and 5.68 and the respective coefficients of digestibility. To.
obtain the available calories from the proteins of the bane
burger and the malted milk.4.25 calories per gram of protein
was used. of a bun 3.70 cal./gm.. and of the chili 3.73
cal./gm.. The value 3.73 cal./gm. used for chili is an
average of 3.20 for legumes and 4.25 for meats since chili is
a combination of the two. These factors 4.25. 3.70. and 3.73
were used in calculating the figures in column 5 of Table II.

The averages of the total physiological fuel value.
calculated by the procedure described above. were 99 calories
for a hamburger. 164 calories for a bun (making a total of
263 calories for a hamburger on a bun). 485 calories for a

malted milk. and 314 calories for a serving of chili con carne.

-26-

The figures for the physiological fuel value of these
foods are included in column 5 of’Table II.

As can be noted from Table I the food portions differ
in size. For ease in comparing the caloric value of a
food product from one establishment with those of other
establishments. calories per gram of serving as purchased
were calculated. The average value for the malted milk
was 1.69 cal./gm. with a standard deviation 0.75. The
average for the hamburger was 3.21 oa1./gm.g with a
standard deviation 0.05. The average for the bun was 3.60
oa1./gm. and the standard deviation. 0.18. The average
value for the chili was 1.11 ca1./gm. and the standard
deviation. 0.20. All the recorded values in calories per
gram for malted milk. buni and chili con carne fell within
the range of the respective standard deviations. The values
in calories per gram of hamburger fell well within.the range
of two standard deviations and those which were outside the
range of'one standard deviation. were very close to the
limits of the range. The caloric values per gram are within
relatively narrow ranges for the respective foods. This
indicates that there is not too much variation in the
formulas used by the different establishments.

However. the portion sizes of foods vary as seen in the
ranges from these five places. The malted milk ranged from

the lowest at 276.7 grams to 331.5 grams: with an average of

-27-

306.2 grams. This variation in portion size is reflected
in.the caloric value per serving which ranged from 378 to
631 calories. with an average of 483 calories. The
hamburger varied from 29.6 grams at one place to 46.1 grams
at another. with an average of 35.8 grams. The caloric
values ranged from 79 to 125 calories. with an average of
99 calories. The bun was relatively constant. The portion
sizes ranged from 47.3 to 52.0 grams (average. 49.8 grams).
This was also reflected in the caloric values. 1. e.. 155 to
177 calories (average. 164 calories) per serving. The
commercial portions of chili showed a varied range from
264.0 to 412.5 grams (average 330.4 grams). The caloric
value per serving spread from 246_to 385 calories (average
314 calories).

In order to determine the protein content of foods. it
has been customary to use the nitrogen analysis and to
obtain protein values of foods by the application of
conversion factors. Through the knowledge of the proteins in
the various types of foods and their percentage of nitrogeni
certain factors have been calculated for use with different
classes of foods. From.Jones we find 6.38 to be the protein
conversion factor for milk. 5.7 for wheat flour (as in a bun).
and 6.25 for foods of animal tissue.

There are limitations to the usage of the protein values
derived from the application of protein conversion factors?

and more accurate knowledge of the relationship of'nitrogan

-23-

in the composition of various foods needs to be deve10ped.
For this reason. it seems somewhat more accurate to record
nitrogen analyses of foods as nitrogen values rather than
converting to protein content. However. the values in food
tables have been commonly expressed as protein values rather
than according to their nitrogen content. Therefore. in
this study protein content has been determined through the
use of the following conversion factors: 6.38 used for
malted milk. 6.25 used for hamburger and chili. and 5.7
used for the bun.

After applying the appropriate conversion factors to
determine the protein content of the foods. the following
averages were found: 9.5 gms./ serving of hamburger. 4.2
gms./ serving of bun (making a total of 13.7 grams protein
per serving of a hamburger on a bun). 12.8 gms./ serving
of.ma1ted milk. and 17.9 gms./ serving of chili con carne.
The nitrogen and protein values of these foods are found in
Table III.

The nitrogen per 100 grams of each food product as
purchased was calculated. The average nitrogen content of
the hamburger was 4.25 grams per 100 grams of the food with
a standard deviation of 0.12. The average for the bun was
1.46 grams of’nitrogen per 100 grams of food with a
standard deviation of 0.04. The average for the malted milk
was 0.66 grams of nitrogen per 100 grams of the food with a
standard deviation of 0.04. The average for the chili con

   

Table III.

NITROGEN AND CALCULATED PROTEIN CONTENT OF HAMBURGER. BUN,
CHILI con CARNE, AND CHOCOLATE MALTED.MILK.

 

 

 

 

 

Food Eating N per N per Pro Per Pro per
Product Estab. Weight. A.P. Serving 100 Grams 100 Grams Serving
grams grams grams grams grams
malted A 298.1 2.05 0.69 4.4 15.1
Milk 3 310.2 1.92 0.62 3.9 12.2
0 276.7 1.80 0.65 4.1 11.5
D 314.4 2.20 0.70 4.5 14.0
B 551.5 2.07 0.62 4.0 15.2 ,
Av. 306.2 2.01 0.66 4.2 12.8 2
8 0004 '
Hamburger A. 46.1 1.89 4.11 25.7 11.8
B 42.0 1.77 4.21 26.3 11.0
0 31.1 1.31 4.23 24.4 8.2
D 30.2 1.28 4.24 ' 26.5 8.0
E 29.6 1.31 4.44 27.7 8.2
AN. 35.8 1.51 4.25 26.5 9.5
s 0.12
Bun A 4905 0075 1052 806 .403
B . 48.5 0.71 1.46 8.3 4.0
0 51.7 0.73 1.41 8.0 4.1
D 47.3 0.70 1.48 8.4 4.0
E 52.0 0.76 1.45 8.3 4.3
Av. 49.8 0.73 1.46 8.3 4.2
I s 0.04
5“ Chill 4 264.0 2.63 1.00 6.2 16.5
B 572.2 2.49 0.67 4.2 15.6
0 555.2 3.46 1.05 6.5 21.6
D 412.5 3.27 0.79 5.0 20.4
B 267.9 2.46 0.92 5.7 15.5
A30 35004 2086 0088 505 1709
8 0.15

 

 

-29..

carne was 0.88 grams of nitrogen per 100 grams of food and
the standard deviation was 0.15.

All the values for nitrogen per 100 grams of malted
milk fell within the range of one standard deviation.

However. all the values for.nitrogen per 100 grams of hamburger.
bun. and chili con carne did not come within the range of one
standard deviation but those values that were without the
ranges of one standard deviation were within two standard
deviations. and very nearly within one. Again. it is evident
that there is relatively close agreement among the formulas
used from.one place to another. However. the protein per
serving varies among the different eating establishments

along with variation in portion sizes. noted before.

The protein grams per serving for malted milk varied
from.11.5 grams to 14.0 grams (average. 12.8 grams); for
hamburger. from 8.0 grams to 11.8 grams (average 9.5 grams);
for a bun. from 4.0 grams to 4.3 grams (average. 4.2 grams);
for chili con earns. from 15.4 grams to 21.6 grams (average.
17.9 grams). The bun again shows constancy in content by
its narrow range in protein per serving from different places.

Comparison of values in the literature are difficult to
make. There are differences in the average portion since both
by weight and by measure. which cause variation in the nutri-
tive values as recorded. Two factors may be considered
responsible for thedifferences. Size servings are inter.

preted differently by the authors of food tables. For example.

-30-

one half cup of chili con carne is considered an average
portion size by some workers (Bridges. 1942; Bradley.
1942): whereas. others state one cup as being an average
size portion (Boyd. et a1.. 1947). This would not present
too great a problem if the weights for definite measures
were the same. For a 10 oz. glass of malted milk. Taylor
(1942) records a weight of 379 grams and Bowes and Church
(1944) give 360 grams as its weight. Compare these weights
with 500 grams of malted milk for 1 1/2 cup scant as
recorded by Bradley (1942). The incorporation of air into
the mixture in the process of whipping the mixture may
account for these discrepancies.

In comparing the results of this study with the figures
feund in food tables. the caloric values for malted milk mu
this study are Eobviously T5 higher than some recorded in
‘the literature. Locke (1911) records 221 calories and 9.7
grams protein for one cup malted milk (containing no ice
cream). Boyd. et a1. (1947) records 287 calories and 8.1
grams protein for one cup malted milk. If the average values
in this study were changed to correspond to one cup measure
of malted milk. there would have been approximately 387
calories and 10.2 grams protein which are higher values than
those of Inocke (1911) or Boyd (1947). The average caloric
value per serving of malted milk in this study was practically
identical with that recorded by Bowes and Church (1944). (483

calories and 480 calories. respectively). 'Yet. the weight

-31-

per serving from Bowes and Church is 360 grams. whereas

the weight per serving in this study was 306 grams. It also
umy be observed that the reports (Taylor. 1942; Bowesand
Church. 1944) in which the caloric values per serving were
similar to the average of this study. also were similar in
protein values. The average amount of protein per serving
recorded in the literature was 13.7 - 13.8 grams for a
malted milk giving 460 - 480 calories (Taylor. 1942; Bowes
and Church. 1944). In this study. the average protein value
per serving was 12.8 grams.

For a serving of hamburger it is difficult to determine
which is the typical weight for a serving of the food. An
average serving was recorded as weighing 57 grams (Rose.
1957). 88 grams (Taylor. 1942) and 25 grams (Bradley. 1942).
This last figure is 10 grams lower than the average weight
(35.8 grams) found in this study. but it is the closest to
the analyzed value of any recorded in the literature. For
25 grams of hamburger. Bradley (1942) records 140 calories
and 8.5 grams protein which are extraordinarily high in
comparison to the values per weight which others have recorded
in the literature (page 19 of the Review of Literature). It
is also high in comparison with the value obtained in this
study. (NOTE: The values (protein 8.5 grams. fat 11.8 grams.
and 140 calories). Bradley records for hamburger. 25 grams.
indicate a water content of approximately 20%;and that the

lamburger is exceedingly concentrated.) Rose records

-32-

100 calories from 57 grams of hamburger and this figure for
caloric value seems low for the size serving. in comparison

to the 99 calories per 35.8 grams hamburger found in this
study. Taylor's figure for size portion (88 grams) seems

rather large in comparison to the 35.8 grams found to be

the average size hamburger. However. the protein value
recorded by her (20.7 grams) is in relative proportion to
the size serving according to the protein values (9.5 grams)
found in this study for 35.8 grams hamburger. The caloric
value. 150 calories for 88 grams. seems low when compared
to the 99 calories’per 35.8 grams as an average serving in
this study.

Boyd. et a1. (1947) was the one reference found in the
literature to report the combined values for a commercial
hamburger and bun. This seems to be a more useful manner
of listing this food product. since it is sold and eaten in
the combined form. Therefore. if the corresponding calorie
and protein values for each hamburger and its bun analyzed
in this study are combined. the following value for a hemp

burger and bun result:

Eating .
Estab, Fgel Valgg Protgin
alories grams
4 280 16.1
B 287 15.0
c 250 12.3
D 241 12.0
E 256 12.5

AVe 265 1305

-33-

In comparing the values from Boyd. et a1. (1947) (11.5
grams protein. 228 calories) for a hamburger and bun with
the results of this study. it is observed that Boyd's
values in theliterature are low for both protein and
calories.

If the values for one half cup chili con carne recorded
in the literature are changed to the values for one cup. an
easier comparison can be made between those values and the
results of direct analysis carried out in this study. One
cup measure is more nearly the measure actually served than
one half cup. The range in serving measure in this study
was from approximately 1 cup to 1 3/4 cup. If this
suggestion is carried out. it will be found that all the
caloric values for chili obtained in this study are within
the limits (230 - 550 calories) listed in the literature.
However. the protein values in this study (15.4 to 21.6 grams)
were lower than those in the literature (range. 21.1 to 35.4
grams for one cup chili). The highest protein value (21.6
game) found for chili in this study was for a serving larger
than one cup. The average caloric value (314 calories for an
average weight of 330.4 grams) for chili in this study is not
too far from the mean of the extremes recorded in the
literature.

From the above observations and discussion it would
appear that the formulas used by the commercial places studied

are relatively standard. The salient difference in food value

per serving lies in the fact that portion sizes differ from
one establishment to another. Nevertheless. the portion
sizes do not vary too greatly. and so. averages from results
of direct analysis may be used for the values of commercial
food servings within certain areas.

The figures as observed here are representative of the
energy and protein values of hamburger. hamburger bun.
milted milk. and chili con carne as they are served commer-
cially in East Lansing. These values are applicable to the
same food mixtures served in other areas of the country
pnly_on the assumption that restaurant practices are similar
and that there may be differences. but not great ones.

It would seem that one of the best ways to check on
these assumptions is to analyze servings of these foods as
they are sold in various areas of the country. Since food
composition tables are composed of averages. perhaps tables
for use in various sections of the country - southeast.
northeast. mid-west. southwest. northwest - would contain

more representative average values.

V. SUMMARY AND CONCLUSIONS

Because food tables are relied upon for the calculation
of the nutritive value of diets. it is necessary that they
be as complete and accurate as possible. Several common
food mixtures are not included in many or any food tables.
If they are included. the nutritive values were calculated
from ingredients rather than by direct analysis. This study
‘was made to provide some information about the proximate
principles of certain food mixtures enjoyed by many persons
in our'society today. particularly college students.

A chocolate malted milk; a hamburger and bun. and a
serving of chili con carne from each of five eating places
in a college community were analyzed for caloric value and
protein content. The foods were airfdried. One half the
serving of each food was acidified and used for nitrogen
determinations acdcrding to the Kaeldahl method. The other
half was used for fuel value determinations using the”
Emerson Fuel Calorimeter. according to the method described
by Hahinr (1952).

Calculation of the protein content was done by applying
the appropriate conversion factors to the nitrogen values
determined by analysis. The "Atwater System" was used to
compute the fuel value of these foods actually available to
the human body.

The values for calories per gram and nitrogen per
100 grams were found to be within relatively narrow ranges
for the reapective foods. This indicated that there was
not too much variation in the formulas used by the different
establishments. flowever. the portion sizes varied from one
place to another accounting for the larger differences in
food value.

The average caloric value of a malted milk was found to
be higher than those recorded in the literature; of a
hamburger. higher in comparison with two cases in the
literature and lower in a third case; of a hamburger and
bun combined. higher when compared with the one analysis
recorded in the literature; of a serving of chili. midway
between the two extremes recorded in the literature.

The average protein value of’a malted milk was found
to be comparable to the higher values recorded in the food
tables; of a hamburger. about the same as that in the L
literature; of a hamburger and bun. slightly higher than
that of the one instance recorded in the literature; and of
chili. lower than the values in the food tables.

Discrepancies in comparing the values of the food mixtures
in this study with those in the literature were pointed out.
Conceptions of portion sizes varied. weights for the same
measure differed. Recipes used for calculations of nutritive

value of food mixtures varied. Many food mixtures pOpular

-37-

in the present day are not included in many food composition
tables. 11' they are found in the literature at all.

It seems necessary. then. that further analyses be made
to bring the current food tables up to date and clear up s
great many discrepancies found therein. These analyses are
needed to confinm. discredit. or add.more infermation about

nutritive values of foods and food mixtures as they are used

today.

VI. LITERATURE CITED

Atkinson. E0

1893 Suggestions for the establishment of food laboratories
in connection with the agricultural experiment stations
of the United States.
U. 8. Dept. ‘grice. off. hper. 3138.. Bulls 17. Page

Atwater. le 00

1895 Methods and results of investigations on the chemistry
and economy of food.
U. S. Dept. Agr10.. offs Exper. Sta. Bulls 21. P. 153s

_ and Bryant. As Po

1899s The availability and fuel value of food materials.
£Q,Report of the Storrs (Conn.) Agric. Exper. Sta..
pp. 73 - 110.

 

_4_ and
1899b Chemical composition of'American food materials. (Rev.)
U. 3. Dept. Agric.. Off. Exper. Sta. Bull. 28.

 

 

Benedict. E. G. and Farr. A. G.

1929 The energy and the protein content of foods regularly
eaten in a college community.
New Hampshire Agric. Exper. Sta. Bull. 342.

Bogart. Le J.
1943 Nutrition and physical fitness. 4th ed.
Philadelphia and London: W. B. Saunders 00.. pp.44l-454

Bowes. A. and Church. 0.
1944 rood values of ortions commonly used. 6th ed.
Philadelphia: ollege Offset Press.

Boyd. 5. 3.. Eads. M. G.. and Sandstead. H. R. .

1947 Food value tables for calculation of diet records.
Washington. D. 5.3 Federal Security Agency. U. 5. Public
Health Service.

Bradley A. Ye
1942 Pables of food values.
Peoria. 111.: The Manual Arts Press.

Bridges M. A. and mattice. M. A.
1942 food and beverage analysis. and ed.
Philadelphia: Lea and Febiger.

Bureau of Human.Hutrition and Home Economics in cooperation

with National Research Uouncil.

1945 Tables of food composition in terms of eleven nutrients.
U. 3. Dept. Agric.. Misc. Publ. No. 572. p. 1.

Chatfield. 0. and Adams. G.
1940 Proximate composition of American food materials.
U. 3. Dept. Agric. Ciro. No. 549.

Donelson. E. G. and Deichsenring. J. M.

1945 Food composition table for short method of dietary
analysis. (R970
.1. Am. mount. n: 440 - 442.

Elvehjem. 0. A.

1946 Symposium on applications of’newer knewledge of nutrition
to present day problems: significance and limitations of
food composition tables.

Fed. Proc.Ԥ: 280 - 285.

food and Agriculture'Organization of the United.Nations.
1947 Committee Report: Energy-yielding components of food
and computation of calorie values.
Washington. De co. Pe 11s

Jones. D. B.

1941 Factors for converting percentages of nitrogen in foods
and feeds into percentages of proteins.
Us so Dept. Agric. Ciro. Nae 1830

LOOkO. E. ‘0
1911 Food values.
New York and London: D..Appleton and 00.

Last, Go
1928 The elements of the science of'nutrition. 2nd ed.
Philadelphia and London: W. B. Saunders 00.. p. 40.

MacLeod" G. and Taylor. C. M. _
1944 our. foundations of nutrition. 4th ed.
New York: The Macmillan 00.. pp. 494 - 568.

Mccance 3. A. and Widdowson. 3. M.
1940 lbs chemical composition of foods.
New York: Chemical Publishing 00.. Inc.

“Shin. 1. ‘
1952 Quantitative analysis. :
New'York and London: McGraw-Hill Book Company. Inc..
pp. 295 ' 2970

-40-

Maynard. D. A.

1944 The Atwater system of calculating the caloric value
Of diets e
J. Nutrition‘gfi: 443.

Merrill. A. L. and watt. B. K.
1948 PhysiolOgic energy values of wheat.
J. ‘m. Dictate ‘0 a} 965 " 9560

Korey. Ne BO

1936-37 An analysis and comparison of different methods of
calculating the energy value of diets.
Nutrition Abstr. to Rev. 5,: 1.

Pettee. A. F.
1929 (Pattee' s) Dietetics. 17th ed.
New York. Putnam' s Sons. pp. 760 - 787.

Richards. E. H.
1902 The dietary computer.
New York: John Wiley and Sons. Inc.

Rose. 9M. 8.
1937 ‘A laboratory handbook for dietetics. 4th ed.
New York: he Naomillan Co.

Sherman. H. C.
1944 Princi 1es of nutrition and nutritive value of food.
pt. Agric. Misc. Publ. No. 546. p.5.

 

1946 Chemistry of food and nutrition. 7th ed.
New York: The Macmillan Co.

Taylor. 0. M.
1948 Food values in shares and weights.
New York: The Macmillan Go.

Farthing; A. G. and Halliday. D.
1943 Heat.
New York; John Wiley and Sons. Inc.. p. 11.

VII 9 APPEN DIX

A. DETAILS OF PROCEDURE USED IN PREPARING DRIED SAMPLES or
fighggg‘. cfigRGER BUN. CHOCOLATE NAMED MILK. AID
W. Prepare 3 large glass trays (rinsed with

distilled water). weigh hamburger. Break hamburger into

small pieces into a clean laring Blender. Add 840 cc. hot
distilled water and blend until a homogeneous mixture is
obtained. To each third part of the mixture add an
additional 100 cc. hot distilled water and.pour into glass
tray. (The 100 cc. of water may be used to transfer-9;
quantitatively. the mixture into the tray.) Air dry with the
use of an electric fan. This may take 3 to 4 hours. When
the mixture is dry in the trays. scrape the dried material
into a mortar. (4 small spatula and rubber scraper are

useful for this.)\ Grind the dried food in a mortar with a

pestile. Weigh the dried.material. The dried food may be

kept successfully if wrapped in ce110phane (with a

pharmaceutical wrap) and stored in a dessicator.

Egg. One tray is all that is required for this food.
Weigh the bun and break it into pieces into the tray. Allow
the sample to air dry using an electric fan. This takes
about 2 hours. Crush in a mortar with a pestile and grind
until the mixture is homogeneous. Weigh the dried food.
lrap in cellophane and store in a dessicator.

-42...

Chili £93; carng. As many as 7 to 12 trays may be
required for a serving of this food mixture. Weigh the

sample of chili. Pour it into a clean Waring Blender and
add 100 cc. of hot distilled water.‘ Blend until it is e
smooth homogeneous mixture. Pour 50 cc. of the mixture
into a pharmacist's graduate and add 50 cc. hot distilled
water. Add an additional 100 cc. hot distilled water to
this and pour the total of 200 cc. into one tray. The 100
cc. of water may be used to transfer} quantitatively. the
mixture into the tray. Do this for as much chili mixture
as there is: for as many trays as are necessary. Air dry
using an electric fan. This may take 4 to 5 hours. When
the mixture is day? scrape it into a mortar and grind with
e pestile. (The scraping process for 4 trays may take as
long as 2 hours.) Weigh the dried material. Wrap in

cellOphane. and store in a dessicator.

. W MB This type of food mixture is not dried
successfully in the same manner as the foods previously
mentioned. It forms a gumplike consistency. Therefore? if
calorimetry is to be done on this food;

Heigh the malted milk. Dill weighed ignition pan from
the calorimeter with malted min: and weigh. Air dry using
en electric fan. This may take as long as 4 to 5 hours.
'eigh the partially dried sample and fill the pan again with
liquid. Air dry. Weigh the dried sample in the pan. Two'

dryings should be sufficient to Obtain a sample large
enough to use in the Emerson Fuel Calorimeter. These
samples in the small pans may be stored for a short time

in a dessicator.

PREPARATION OF PELLETS FOR USE IN THE CALORIMBTER.

It has been found that if the substance to be oxidized
is reduced in moisture content; and thenfi if it is pressed
into a compact ferm.(such as the shape of a pellet): s
more complete combustion of the material is effected. For
the particular foods mentioned here the following suggestions
are made concerning the formation of these pellets.

id. .Egmhugggg. Use a hand press.

3. .Efllm Use the hydraulic press up to a pressure of 800
pounds to 1000 pounds.

0. 93;}; m car . Use a hand press.

9442

B. Table IV. RECOVERY OF NITROGEN FROM A STANDARD SOLUTION.

 

 

Nitrogen Percent of
in Nitrogen Nitrogen
.Efterial Date Sample Recovered Recovered
" " grams grams
N340]. 5/21/49 .ooso .0629 96.8
.0650 .0634 97.5
.0650 .0645 99.2
Average 97.8

 

Table V. DETERMINATION OF IZTER STANDARD FOB CALORIMETER
USING BENZOIO ACID.

 

 

 

Approximate
Error of
Results of Tests Deviations from Mean Experiment
Calories calories percent
2567.5 15.0
8537.1 15.2
2562.0 9.7
2544.5 7.8
2569.5 17.2
2552.0 0.3
2538.8 13.5
2543.5 903
2557.3 5.0
Average ”
2552.3 10.4

0.4

 

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