Tài liệu STUDIES IN NUTRITION pptx

In experiments on a man, Hoffmann found the nitrogen of a diet of lentils, bread and potatoes to be 53 per cent available, against a utilization of 82 per cent for the nitrogen of mea

IV THE UTILIZATION OF THE PROTEINS OF THE LEGUMES

BY LAFAYETTE B MENDEL AND MORRIS 5 FINE

(From the Shejield Laboratory of Physiological Chemistry, Yale University,

New Haven, Connecticut.) (Received for publication, September 25, 1911.)

CONTENTS

Earlier studies

Experimental part

Products employed

Metabolism experiments

Soybean

White bean

Crude bean protein

Phaseolin

Pea globulin

Nitrogen balances

Summary

433

435

435

437

437

446

448

454

454

456

457

EARLIER STUDIES

The literature on this subject has been so adequately reviewed

by Wait, that only the most cursory consideration of the earlier

work need find place here In experiments on a man, Hoffmann

found the nitrogen of a diet of lentils, bread and potatoes to be

53 per cent available, against a utilization of 82 per cent for the

nitrogen of meat Woroschiloff compared the utilization of the

protein of peas with that of meat protein In three cases the meat

protein was 90, 92, and 96 per cent utilized against 83, 88, and 90 per cent for the digestibility of the protein of the peas Strtimpell

ground commercial preparation, consisting of a mixture of lentils,

peas and rye-to be 90 per cent available, against a utilization of

434 Utilization of Legume Proteins

but 60 per cent in an experiment with unground lentils Rubner

has pointed out that in the experiments of both Woroschiloff and

Strtimpell, materials other than legumes were eaten, and these accessories may have exerted a favorable influence Accordingly,

Rubner conducted two experiments with thoroughly cooked hulled

peas which were the only food consumed The utilization was 72

to 83 per cent In Malfatti’s experiments, peas were 86 per cent utilized and Potthast found lentils to be 74 per cent digested

In an experiment by Prausnitz, white beans, soaked for several hours and then cooked till soft, yielded 70 per cent available

nitrogen Erismann found the nitrogen of peas to be 80 per cent digested Richter obtained a utilization of 90 per cent for the nitrogen of peas cooked in distilled water, against 83 per cent when hard water was employed in the process of cooking Under the latter condition particles of apparently unchanged peas were ob- served in the feces The poor digestibility of the peas cooked in hard water is attributed in part to the formation of difficultly

digestible alkali earth albuminates, and in part to the digestive

disturbance due to the magnesium salts in the water Snyder

reported a utilization of 80 per cent for the protein of peas, and obtained a similar result with beans In their experiments with

the Maine lumbermen, Woods and Mansfield estimated the pro- tein of beans to be at least 78 per cent utilizable, and an average digestibility of 65 per cent is reported in Oshima’s compilation of Japanese investigations In a very thorough study, Wintgen

found the average coefficients of digestibility of lentils, beans, and peas to be 78, 80 and 86 per cent respectively Wintgen’s results are in accord with those obtained in an extensive investigation by Wait, in which a utilization of 77 to 78 per cent was obtained for bean protein, and 70 to 83 per cent for cow pea protein

In commenting upon this literature one can but reiterate the statements made in a previous paper’ of this series, and point out the necessity for studying the utilization of the isolated protein, or material in which the protein is more readily accessible to the digestive juices

1 Mendel and Fine: This Journal, x, p 303, 1911

EXPERIMENTAL PART

Products Employed

1 SOY BEAN.' This material was an impalpable yellow pow-

der, which betrayed no cellular structure under the microscope

In respect to consistency, it would thus appear to be ideal for

digestion experiments As may be observed from the accompany-

ing analysis,2 the soy bean offers several points of interest:

Protein

Fat

Cane sugar

Mineralmatter

Crude fiber

Moisture

Non-nitrogenous extract

per cant 44.6 19.4 9.3 4.2 2.3 5.3 14.5 Its content of protein and fat far exceeds that of any other

legume, which condition seems to have been appreciated in Japan;

for, according to Oshima, it is next to rice in importance in the

Japanese dietary.s In addition to cane sugar, the presence of

galactans and of pentosans has been detected by Schulze and his collaborators.4 The soy bean does not give the ordinary iodine

test for starch.6

2 WHITE BEAN This was the ordinary white bean of com-

merce

white bean are subject to the same criticism as has been offered in

connection with the work of previous investigators The attempt

was here made to thoroughly rupture the cells and dissolve and

wash away the starch The method in brief was as follows: about

1 Mr M F Deming of the Cereo Company, Tappan, N Y., very kindly

contributed this material

2 Reported by Ruhriih: Journal of the American Medical Association, liv,

p 1664, 1910

* Oshima, (see bibliography) gives an interesting account of the various

soy bean preparations, which are common articles of diet in Japan

4 For the literature, see Schulze and Godet : Zeitschrift fiir phpiologischc

Chemie, lxi, p 279, 1999

6 Cf Oshima: Zoc:cit p 26

436 Utilization of Legume Proteins

5 pounds of finely ground hulled beans1 were mixed with water

and heated in a glycerol bath After the mixture had been held

near 100” C for about an hour, the thin mush which had formed

was cooled below 75” C and a glycerol extract of malt diastase

added, as a result of which, after a few minutes, starch could no

longer be detected with iodine in a test-tube trial The material

thus obtained was washed by decantation and the water driven off

by heat until about 20 per cent was made up of solid matter The

resulting preparation was a thick mush, which could be conven-

iently pressed into cakes and preserved frozen Although no

iodine test for starch was obtained in a test-tube trial, nevertheless,

when a sample treated with this reagent was examined under the

microscope, not infrequently starch grains were observed within

cells, which had apparently not in any way been affected by the

treatment to which they had been subjected This insufficient

rupture undoubtedly accounts for the incomplete conversion of

the starch

Analysis of Crude Bean Protein (calculated for anhydrous material)

per cent Protein(NX 6.25) 51.1

Sugar from insoluble carbohydrate (by hydrolysis) 28.9

Sugar from soluble carbohydrate (by hydrolysis) 2.4

Ash , 2.6

Ether extract* 4.0

Crudefiber(bydifference) 11.0

‘Estimated from Atwaterand Bryant: U 9 Department of Aprlculture, Bull 28 (Revised)

p 66, 1906 Material was not available for analysis

Attention is called to the fact that a barley protein preparation2

with approximately the same concentration of protein contained

practically no cellular structure or starch, yet yielded 20 per cent

of carbohydrate by hydrolysis The latter was believed to be hemicelluloses It is thus probable that a not inconsiderable portion

of the “carbohydrate by hydrolysis” of the above analysis was in reality also made up of hemicelluloses.3

1 Furnished by Mr Deming who also prepared a considerable portion of the crude bean protein for us according to the method outlined

a Mendel and Fine: This Journal, x, p 340, 1911

* At the time of proof reading we learn through a private communication

from Prof E Schulee that hulled beans, phaseolus vulgaris, contain 12.9 per cent, hemicellulose We estimate the hemicellulose concentration of our preparation at approximately 25 per cent

4 PHASEOLIN This material was very kindly furnished by

Dr T B Osborne It was dried, ground to an impalpable powder,

and found by analysis to contain 13 per cent of nitrogen

5 PEA GLOBULIN This material was prepared as follows:

dried peas were finely ground and repeatedly extracted with 10 per cent NaCl solution The perfectly clear extract thus obtained

was saturated with ammonium sulphate, the resulting precipi-

tate being collected on a filter paper, suspended in a small amount

of water to which toluene had been added and dialyzed for about

two weeks, that is, until free from sulphates Part of the prepar-

ation was obtained by dialyzing the saline extract, thus avoiding

the necessity of the precipitation with ammonium sulphate The

resulting precipitate was dried at 40” to 50” C., ground to an im-

palpable powder and found by analysis to contain 16 per cent of

nitrogen

Metabolism Experiments

SOY BEAN Man,l Table 1: The ordinary routine was followed:

a fore period (preceded by a three day adjustment period), during

which a mixed diet was consumed; experimental period, in which

over 90 per cent of the nitrogen ingested was furnished by soy bean; and an after period essentially like the fore period The

Daily Averages Daily Aversgea

70

200

character of the diet is outlined below:

Character of Diet

Dally Averages

Cracker

Egg

Peanut butter

Meat

Soy bean

Potato

Tomato

Apple

Orange

Milk

Sugar

Butter ,

Cereal coffee, tea

grams

70

100

75

140 loo

250

200

130

60

130

50

600

190

165

120

600

1 The subject was one of us (M 5 F.) twenty-four years of age, leading

the usual active life of the laboratory

438 Utilization of Legume Proteins

As will be observed, during the experimental period the cracker,

egg, meat, and nut butter were completely replaced by soy bean,

which furnished 91 per cent of the total nitrogen intake of this

period The daily nitrogen and calorific intakes in these periods

were fairly constant, averaging about 12.6 grams and 2500 calories,

respectively The soy bean was boiled in water for one-half

hour, salted to taste, and the tomatoes thoroughly incorporated

into the resulting mush The palatability of the mixture was still

further increased by the addition of a very small amount of pap-

rika On the whole it may be said that this fare proved quite

period of six days

Nitrogen, per cent

Nitrogen utilization, pel

cent

Meat, egg, nut butter, potato, fruit, etc

Estimated calories 240

Dtiy Averages

9.56 11.11 12.78 +1.67

Soy bean, fruit, etc., 90.5 per cent total nitro- gen supplied

by soy bean

Estmated calories 240(

Estimated calories 2600

Daily Averages Dally Averages

The subject felt in excellent condition throughout the entire

experiment Defecation took place regularly every morning and

no diarrhoea occurred

It will be observed from Table 1, that the soy bean nitrogen is

distinctly (if only slightly) less well utilized than that of the preced-

ing and succeeding mixed diets The nitrogen concentration of the feces of the soy bean period is higher than in any other experi-

ment on this subject which indicates that some soy bean protein

escaped absorption

Dog 1, Table 2, was fed with a mixture of soy bean, lard, agar, bone ash and water It was heated on the water bath for four to six hours, the purpose being to thoroughly “hydrate” the material,

which, as fed to the animal, was a thick mush

Dogs 6 and 7, Tables 3 and 4, were fed with similar ingredients

and sugar in addition The mixture, including the water, was not

heated, but allowed to stand over night, after which the material

appeared to be thoroughly “hydrated ”

The plan of experimentation differed in no particular from those previously followed, and we may therefore proceed directly to an examination of the tables, which contain all the essential details

In the dog, the soy bean was in every case strikingly less well util-

ized than the meat fed under similar experimental conditions, and one also notes the persistently higher nitrogen concentration of the feces of the soy bean periods as compared with that of the meat-

feces This is an indication, as noted above, that some soy bean protein has probably escaped digestion

440 Utilization of Legume Proteins

Soy Bean with Agar and Bone Ash

BUB.lEc!T, DOG 1 PERIOD III PERxoD 1vt PERIOD v

I

Meat Lard 3g paTdbean 1% ygi

grama 36$

C;~e~sition of daily Agar* Bone ash 15 Boneash 5 Agar 15 Bone ash 5 Agar 15 5

Water 300 Water 500 Water 300 Estimated Estimated Estimated calories 1070 calories 1110 calories 1070 Nitrogen output Daily Averages Dally Averages Dsfly Averages

Nitrogen utilization, per

cent I 95.0 I 83.8 I 94.5

l On the first two daya of the

aah This produced brittle feces

eriod, the “indineatlble” was represented by 20 grams bone

g ployed aa noted in the table

ence in the remaining three days agrtr and bona ash were em-

t Forced feedIng necessary throughout the period-no vomftlng

Nitrogen, per cent

Nitrogen utilization, pel

cent

n with Agar al PERIOD VI

(4 days) Meat Feeding grams

Meat 150

Boneash 7 Water 100 Estimated calories 510

Daily Averages

3.71 4.11 4.93 +0.82 15.5 0.40 2.60 91.8

gnwns soy bean Fig

!%? 25

Boneash 7 Water ZOO Estimated calories 570

Daily Averagea Dally Averages

3.01 4.26 4.90 +0.64

2z

4:80 +0.36

92.7

Nitrogen output Daily Averages

Nitrogen, per cent

Nitrogen utilization, per

12.7 0.26 2.04 cent 92.1

-

_-

-

i Bone Ash

PERIOD VI (6 days) Soy Bean Feeding

&mw?u Soy bean 47 Sugar 20

Bone ash 7 Water 175 Estimated calories 490 Daily Averages 2.38 3.04 3.34 +0.30 20.5 0.66 3.22 80.2

~rarnd

Meat 100 Sugar 20

Bone aah 7 Water 100 Estimated calories 430 Daily Averages 2.55 2.79 3.20 +0.41 12.8 0.24 1.86 92.6 SOY BEAN Dogs (without agar and bone ash)-Tables 6 to 13: These experiments were conducted in essentially the same manner

as those just reported, except that the indigestible adjuvants-

agar and bone ash-were omitted Tables 8 to 10 contain the

results of trials instituted after the intestinal tract had been sub-

jected to a thorough treatment with indigestible non-nitrogenous

materials, the purpose being to remove as far as possible the accu-

mulated intestinal debris

Proceeding directly to a study of the tables, we again note the

poor utilization of the soy bean nitrogen A fuller discussion of

these data with a consideration of the attending conditions will

be offered below’ in connection with the discussion of the results

obtained with the crude bean protein

In Oshima’s compilation one notes that certain soy bean products

(e.g., tofu) are as much as 96 per cent utilizable Tofu, however,

is probably of an albumose nature and such favorable results should

442 Utilization of Legume Proteins

Soy Bean without Agar or Bone Ash

BUBJECT, DO0 6

Weight at beginning, 6.9 Kg

Weight at end 6.0 Kg

Composition of daily diet

1 Nitrogen output Urine nitrogen, gm

Total nitrogen, gm

Nitrogen in food, gm

Nitrogen balanwLcr Weight air dry, gm

Nitrogen, gm

Nitrogen, per cent

Nitrogen utilization, per cent * One-quarter to one-half of the food forced each day PERIOD xxx* (5 daya) Soy Bean Feeding grams gmnu Meat 150 Soy bean EEY 2 k:: 2 Water 100 Water !z Estimated Estimated calories 530 calories 530 Dally Averagea Dally Averages 4.08 3.96 4.30 4.66 4.59 4.61 +0.29 -0.05 $12; 95.2 17.8 0.70 _

8E TABLE 6 Sol/ Bean without Agar or Bone Ash i31JBJEcrl, DOB 6 Weight at beginning, 6.1 Kg Weight at end, 6.3 Kg Composition of daily diet

1 Nitrogen output Urine nitrogen, gm

Nitrogen balance~e~~ Weightairdry,gm

Nitrogen, gm

Nitrogen, per cent

Nitrogen utilization, per cent

-

_-

@m?zs

pw$

E

Estimated calories 530

.’

-

Daily Averages

E

4:59 +0.82 3.5 0.22

929

- .-

<

L

1

1

.-

-

PERIOD XXII (6 days) Soy Bean Feeding

3oy bean Dram 64

2; zi

Estimated calories !

3.42 4.16 4.61 +0.45 18.2 0.74 4.04 84.0

TABLE 7

Soy Bean without Agar or Bone Ash

Weight at beginning, 6.9 Kg

Weight at end, 6.3 Kg

Composition of daily diet ’

Nitrogen output Urine nitrogen, gm

Total nitrogen, gm

Nitrogen, in food, gm

Nitrogen balanc;;cz Weightairdry,gm I

Nitrogen, gm

Nitrogen, per cent

Nitrogen utilization, per cent

PERIOD xx (4 days) Meat FeedIng grams Meat 150 !3 ii Water 100 Estimated calories 530 Daily Averama Daily Aversnea 3.55 3.74 4.59 +0.85 3.2 0.19 5.93 95.8 TABLE 3 Soy Bean without Agar or Bone Ash - _- PEBIOD XXI (5 days) Soy Bean Feeding Soy bean g,llWZ* i%S c Water 2;: Estimated calories 530 - 3.41 4.21 4.61 +0.40 16.2 xz 82:8 SUBJECT, DOG 5 Weight at beginning, 6.2 Kg Weight at end, 6.2 Kg Composition of daily diet

I Nitrogen output Urine nitrogen, gm

Total nitrogen, gm

Nitrogen in food, gm

Nitrogen balanc;;cz Weightairdry,gm :

Nitrogen, gm

Nitrogen, per cent

Nitrogen utilization, per cent

grama

ii Lard

Estimated calories 530

Daily Averages

3.66 4.31 4.61 +0.30

!ara?na

Lard

Estimated calories 530

Dailv Averarres

3.68 2:

+0.&l

*About half of the food forced each day

444 Utilization of Legume Proteins

Soy Bean without Agar or Bone Ash

Composition of daily diet

Nitrogen output Urine nitrogen, gm

Total nitrogen Nitrogen in foo ,fm’

, gm

Nitrogen balance, gm

I Soy bean pz; 2”; Water 2% Estimated calories 530 Dally Averages 3.45 4.06 4.61 +0.55 Meat 150 !2% 25 Water 1: Estimated calories 539 Dally Averages 3.35 3.59 Feces Weight air dry, gm

Nitrogen, gm

Nitrogen, per cent

Nitrogen utilization, per cent

16.7 4.4 0.61 0.24 3.64 86.8 9::: TABLE 10 Soy Bean m’thout Agar or Bone Ash BUBJECT, DOCI 7 Weight at beginning, 6.6 Kg Weight at end, 6.6 Kg Composition of daily diet

Nitrogen output Nitrogen output Weight air dry, gm .*

Nitrogen, gm

Nitrogen, gm

Nitrogen, per cent

Nitrogen, per cent

Nitrogen utilization, per cent

Nitrogen utilization, per cent

grams

Soy bean

Estimated calories 530

Daily Averagea

3.78 4.61 +0.26

Meat

gmmr

150

Ed? ii

Estimated calories 530

Dally Averages

zz 4.64 +0.89

TABLE 11

Soy Bean without Agar or Bone Ash

IOBJECT, DOG 5

We

8

ht at beginning, 6.0 I&

eight at end, 5.9 Kg

Composition of daily diet

Nitrogen output Urine nitrogen, gm

Total nitrogen, gm

Nitrogen in food, gm

Nitrogen balanc$e;; Weight air dry, gm

Nitrogen, gm

Nitrogen, per cent

Nitrogen utilization, per cent

PmuOD XVI PHlRIOD XVII (4 days) (4 days) Meat Feeding Soy Bean Feeding Meat k.% Water Estimated calories ;yap Lard Water Estimated calories Dally Averaaes 1 Dally Averagea 2.77 2.83 2.79 3.48 3.28 3.31 +0.49 -0.17 0.4 E; 99:4* 14.0 0.65 4.67 80.2 * Feces evidently separated Imperfectly TABLE 12 Soy Bean without Agar or Bone Ash BUEZJE~~, DOG 6 Weight at beginning, 6.2 Kg Weight at end, 6.1 Kg Composition of daily diet

Nitrogen output Urine nitrogen, gm

Total nitrogen, gm

Nitrogen in food, gm

Nitrogen balanc;;cr Weightairdry gm I

Nitrogen, gm

Nitrogen, per cent

Nitrogen utilization, per cent

(4 days) Meat Feeding

grcrms

Estimated calories 450

Dally Averages

2.41 2.54 3.28 +0.74

kh 7.03 96.0

grams

Soy bean

Estimated calories 460

Daily Averages

2.49 3.21 3.31 +0.10 14.0 0.72 5.15 79.3