The metabolism of nitrogen and the digestibility coefficient and biological value of the proteins and net protein utilization in poor rice diet supplemented with methionine-fortified soya flour or skim milk powder


Panemangalore, M.; Parthasarathy, H.N.; Joseph, K.; Sankaran, A.N.; Rao, M.N.rayana; Swaminathan, M.

Canadian Journal of Biochemistry 42(5): 641-650

1964


The effect of supple-menting a poor rice diet commonly used in India with methionine-fortified soya flour or skim milk powder was studied in seven girls aged 8-9 years, using as criteria: the retention of nitrogen, digestibility coefficient, biological value, and net protein utilization of the proteins. The retention of nitrogen on the rice diet was very low (20.3 mg/kg day). Supplementation of the rice diet with soya flour, methionine-foritfied soya flour or skim milk powder, so as to provide about 1 g/kg extra protein, made up the protein deficiency in the rice diet and resulted in a significant increase in nitrogen retention (95.6, 112.1, and 113.6 mg/kg day). The retention of nitrogen on the rice diet supplemented with methionine-fortified soya flour (112.1 mg/kg day) or skim milk powder (113.6 mg/kg day) was nearly the same and significantly higher than that (95.6 mg/kg day) observed with a diet supplemented with soya flour. The biological value and net protein utilization of the mixed proteins of rice-skim milk powder diet and rice-methionine-fortified soya flour diet (62.4 and 62.2 and 53.3 and 54.0 respectively) were nearly the same and significantly higher than those (58.3 and 49.9) of rice-soya flour diet. The results show that methionine-fortified soya flour is almost as good as skim milk powder and significantly superior to soya flour as a protein supplement to rice diet.

THE
METABOLISM
OF
NITROGEN
AND
THE
DIGESTIBILITY
COEFFICIENT
AND
BIOLOGICAL
VALUE
OF
THE
PROTEINS
AND
NET
PROTEIN
UTILIZATION
IN
POOR
RICE
DIET
SUPPLEMENTED
WITH
METHIONINE-FORTIFIED
SOYA
FLOUR
OR
SKIM
MILK
POWDER
MYNA
PANEMANGALORE,
H.
N.
PARTHASARATHV,
KANTHA
JOSEPH,
A.
N.
SANKARAN,
M.
NARAYANA
RAO,
AND
M.
SWAMINATHAN
Central
Food
Technological
Research
Institute,
Mysore,
India
Received
November
19,
1963
Abstract
The
effect
of
supplementing
a
poor
rice
diet
commonly
used
in
India
with
methionine-fortified
soya
flour
or
skim
milk
powder
was
studied
in
seven
girls
aged
8-9
years,
using
as
criteria:
the
retention
of
nitrogen,
digestibility
coefficient,
biological
value,
and
net
protein
utilization
of
the
proteins.
The
retention
of
nitrogen
on
the
rice
diet
was
very
low
(20.3
mg/kg
day).
Supplementation
of
the
rice
diet
with
soya
flour,
methionine-fortified
soya
flour
or
skim
milk
powder,
so
as
to
provide
about
1
g/kg
extra
protein,
made
up
the
protein
deficiency
in
the
rice
diet
and
resulted
in
a
significant
increase
in
nitrogen
retention
(95.6,
112.1,
and
113.6
mg/kg
day).
The
retention
of
nitrogen
on
the
rice
diet
supplemented
with
methionine-fortified
soya
flour
(112.1
mg/kg
day)
or
skim
milk
powder
(113.6
mg/kg
day)
was
nearly
the
same
and
significantly
higher
than
that
(95.6
mg/kg
day)
observed
with
a
diet
supplemented
with
soya
flour.
The
biological
value
and
net
protein
utilization
of
the
mixed
proteins
of
rice
-
skim
milk
powder
diet
and
rice-methionine-fortified
soya
flour
diet
(62.4
and
62.2
and
53.3
and
54.0
respec-
tively)
were
nearly
the
same
and
significantly
higher
than
those
(58.3
and
49.9)
of
rice
-
soya
flour
diet.
The
results
show
that
methionine-fortified
soya
flour
is
almost
as
good
as
skim
milk
powder
and
significantly
superior
to
soya
flour
as
a
protein
supplement
to
rice
diet.
Introduction
There
is
an
acute
shortage
in
the
production
of
protein-rich
foods
such
as
milk,
meat,
fish,
and
eggs
in
several
countries
emerging
into
a
new
phase
of
industrial
development
(1).
In
view
of
this,
the
problem
of
providing
alternative
sources
of
supplementary
protein
foods
based
on
locally
available
plant
pro-
teins
such
as
oilseed
meals
and
legumes
has
received
the
attention
of
a
number
of
research
workers
and
also
of
international
agencies
(2-5).
Among
vegetable
sources,
soya-bean
meal
contains
proteins
of
high
nutritive
value
(6).
Joseph
et
al.
(7)
reported
that
fortification
of
soya
bean
with
DL-methionine
signifi-
cantly
improved
the
nutritive
value
of
the
proteins,
the
product
comparing
well
with
that
of
milk
proteins.
It
appeared
possible
that
soya-bean
meal
fortified
with
methionine
could
be
used
as
an
effective
supplement
to
the
diets
of
children
in
place
of
milk
in
developing
countries.
In
the
present
investiga-
tions,
the
effect
of
supplementing
a
rice
diet
with
skim
milk
powder
or
soya-
bean
meal
fortified
with
methionine
at
a
level
to
provide
1
g/kg
extra
protein
has
been
studied
in
children,
using
the
digestibility
coefficient
(DC),
biological
value
(BV),
and
net
protein
utilization
(NPU)
of
the
proteins
as
criteria
of
improvement.
Canadian
Journal
of
Biochemistry.
Volume
42
(1964)
641
642
CANADIAN
JOURNAL
OF
BIOCHEMISTRY.
VOL.
42,
1964
Experimental
Hater
ials
Soya
flour
used
in
this
study
was
prepared
according
to
the
following
pro-
cedure.
Decorticated
soya
bean
dhal
(split
dehusked
legume)
was
soaked
in
water
and
autoclaved
at
10
lb
pressure
for
30
minutes,
debittered
by
treatment
with
sodium
bicarbonate
according
to
Desikachar
et
al.
(S),
and
then
dried
at
50-55°
C
in
a
cabinet drier.
The
oil
was expressed
in
a
screw
press
and
the
resulting
cake
was
powdered
in
a
flour
mill.
to
pass
through
a
50-mesh
sieve.
The
product
contained
54.6%
protein
(N
X6.25)
and
was
found
to
be
free
from
tryptic
inhibitor,
when
tested
according
to
Anson
(9).
The
processed
soya
flour
was
fortified
with
DL-methionine
(E.
Merck)
at
a
level
of
1.2
g/16
g
N
by
dry
mixing.
An
imported
sample
of
skim
milk
powder
of
good
quality
was
used.
Plan
of
Study
The
plan
of
the
metabolic
study
and
analytical
methods
used
were
similar
to
those
described
by
Joseph
et
al.
(10)
in
their
studies
with
ragi
diets.
Subjects
The
subjects
of
the
study
were
girls
(aged
8-9
years)
resident
in
a
local
boarding
home
in
the
city
of
Mysore.
The
heights
and
weights
of
the
girls
varied
from
108.6-123.1
cm
and
15.7-20.0
kg
respectively;
the
average
height
and
weight
was
115.1
cm
and
18.5
kg.
They
belonged
to
low-income
groups
and
were
subsisting
on
a
rice
diet
similar
to
the
one
used
in
this
experiment.
The
girls
were
examined
clinically
and
found
free
from
diseases
likely
to
interfere
with
the
experiment.
Experimental
Diets
and
Feeding
of
Children
The
rice
diet
used
in
the
present
investigation
was
similar
to
that
usually
consumed
by
the
children
in
the
boarding
home.
It
consisted
mainly
of
rice
and
small
amounts
of
legumes,
vegetables,
oil,
and
skim
milk
powder.
The
mean
daily
intake
of
foodstuffs
by
the
children
from
the
different
diets
is
given
in
Table
I.
The
subjects
were
fed
three
times
a
day.
The
pattern
of
breakfast,
lunch,
and
dinner
was
similar
to
that
described
by
Reddy
et
al.
(11).
TABLE
I
Mean
daily
intake
(g)
of
foodstuffs
by
the
children
on
the
different
diets*
Dietst
Supplementary
foods
A
Corn
starch
Sugar
Soya
flour
Methionine-fortified
soya
flour
Skim
milk
powder
27.0
50.0
39.0
39.6
39.0
27.0
36.6
55.0
*Basal
diet
(g)
common
to
all
groups:
rice,
raw
milled,
300.0;
red
gram
dhal
(Cajanus
cajan)
20.0;
peanut
oil,
6.0;
brinjal
(egg
plant)
(Solanunz
mclongena),
20.0;
potato,
20.0;
amaranth
(a
leafy
vegetable)
(Anzaranthus
gangeti-
cus),
10.0;
tamarind
fruit
pulp
(Tamarindus
indicus),
6.0;
skim
milk
powder,
5.0;
onion,
14.0;
condiments
(garlic,
coriander
seeds,
mustard,
red
chillies,
turmeric),
8.8.
tA,
rice
diet;
B,
rice
+
soya
flour
diet;
C,
rice
+
methionine-fortified
soya
flour
diet;
and
D,
rice
+
skim
milk
powder
diet.
PANEMANGALORE
ET
AL.:
RICE
DIET
643
The
protein
supplements
were
given
in
three
doses
along
with
breakfast,
lunch,
and
dinner.
The
essential
amino
acid
composition
of
the
mixed
proteins
of
the
different
diets
consumed
by
the
children,
determined
according
to
the
methods
of
Krishnamurthy
et
al.
(12),
is
given
in
Table
II
along
with
the
FAO
reference
protein
pattern
(13)
and
Ideal
reference
protein
pattern
suggested
by
one
of
us
(14).
The
procedure
adopted
for
the
feeding
of
children
and
for
the
collection
of
excreta
was
similar
to
that
of
Joseph
et
al.
(10).
The
diets
were
given
to
the
children
in
the
following
order:
(1)
rice
diet
(diet
A);
(2)
rice
diet
+
soya
flour
(SF)
(diet
B)
;
(3)
rice
diet
+
inethionine-fortified
soya
flour
(SF-Met)
(diet
C);
(4)
rice
diet
+
skim
milk
powder
(SM
P)
(diet
D);
and
(5)
low-protein
diet.
Each
diet
was
given
for
a
period
of
10
days.
The
first
5
days
were
considered
a
preliminary
period
of
adjustment,
the
faeces
and
urine
being
collected
during
the
last
5
days
of
each
period.
Carmine
was
used
as
a
marker
for
the
collection
of
faeces.
A
check
on
the
proper
collection
of
urine
was
maintained
by
determining
the
daily
excretion
of
creatinine.
The
daily
excretion
of
creatinine
in
the
subjects
ranged
from
470
mg
to
510
mg
per
day
and
of
creatine
50
to
75
mg
per
day.
In
the
same
subject
the
daily
excretion
of
creatinine
and
creatine
on
different
days
during
the
metabolism
period
did
not
differ
by
more
than
5%,
indicating
that
the
collection
of
urine
was
almost
quantitative.
Since
the
experimental
periods
were
of
short
duration,
the
design
adopted
was
not
likely
to
affect
the
interpretation
of
results.
The
low-protein
diet
(Table
III)
consisted
of
savoury
and
sweet
preparations
made
from
a
vermicelli-like
product
obtained
from
cooked
maize
starch
and
washed
tapioca
flour,
sago
pudding,
lime
juice,
and
vegetable
soup.
The
urinary
and
faecal
nitrogen
excreted
by
the
subjects
on
the
low-protein
diet
have
been
considered
as
values
for
endogenous
nitrogen
excretion.
Analytical
Data
The
nitrogen
content
of
the
diet,
urine,
and
faeces
was
determined
by
the
Kjeldahl
method.
The
true
digestibility
coefficient
and
biological
value
of
the
proteins
and
net
protein
utilization
(operative)
(NPU
(0)
)
of
the
diets
were
calculated
according
to
the
formulae
given
in
an
earlier
paper
(15).
Results
Data
regarding
the
endogenous
urinary
and
faecal
nitrogen
are
given
in
Table
IV
and
those
of
digestibility
coefficient,
biological
value,
and
net
protein
utilization
in
Table
V.
The
net
available
protein
in
children
on
the
different
diets
is
given
in
Table
VI.
The
intake
and
absorption
of
essential
amino
acids
(mg/kg)
from
the
different
diets
as
compared
with
the
amino
acid
require-
ments
are
given
in
Table
VII.
Essential
Amino
Acid
Composition
and
Protein
Scores
(Table
II)
The
protein
scores
of
the
different
diets
as
compared
to
FAO
reference
pro-
tein
pattern
and
Ideal
reference
protein
pattern,
calculated
according
to
the
method
of
FAO
Committee
(13),
are
as
follows:
rice
diet,
70
and
61;
rice
+
SF
diet,
74
and
65;
rice
+
SF-Met
diet,
79
and
69;
and
rice
+
SMP
diet,
75
and
644
CANADIAN
JOURNAL
OF
BIOCHEMISTRY.
VOL.
42,
1964
TABLE
II
Essential
amino
acid
content
(g/16
g
N)
of
the
mixed
proteins
of
the
different
diets
Amino
acid
Diets
FAO
reference
protein
pattern
Ideal
reference
protein
pattern
A
B*
D
Arginine
5.63
6.49
4.80
6.6
Histidine
1.88
2.28
2.23
-
2.4
Lysine
4.28
5.46
5.87
4.2
7.5
Leucine
8.28
8.08
9.04
4.8
10.0
Isoleucine
4.88
5.23
5.59
4.2
6.6
Methionine
1.67
1.60
2.03
2.2
2.8
Cystine
1.28
1.51
1.12
-
2.0
Total
sulphur
amino
acids
2.95t
3.11
-
f
3.15t
4.2
4.8
Phenylalanine
5.46
5.31
5.24
2.8
5.8
Threonine
3.83
3.91
4.21
2.8
5.0
Tryptophan
0.95
1.10
1.17
1.4
1.6
Valine
6.46
5.91
6.70
4.2
7.0
Protein
score
Ideal
reference
protein
61
65
66
100
FAO
pattern
70
74
75
100
*Essential
amino
acid
content
(g/16
g
N)
of
diet
C
was
the
same
as
that
of
diet
B
except
in
the
following
respects:
methionine,
2.12;
total
sulphur
amino
acids,
3.63.
tAmino
acid
limiting
as
compared
to
FAO
reference
protein
pattern
or
Ideal
reference
protein
pattern.
Protein
scores
of
diet
C
were
69
and
79
according
to
Ideal
reference
protein
and
FAO
reference
protein
pattern
respectively.
TABLE
III
Mean
daily
intake
of
foodstuffs
on
a
low
protein
diet*
Foodstuff
Quantity
(g)
Corn
starch
87.0
Tapioca
flour
(washed
with
alkali)
150.0
Cane
sugar
50.0
Peanut
oil
50.0
Vitaminized
starch
t
5.0
Salt
mixtures
5.0
Common
salt
12.5
Onion
14.0
Tamarind
fruit
(Tamarindus
indicus)
pulp
6.0
Condiments
8.8
Vegetables
30.0
Lime
juice
60.0
ml
*Nitrogen
content
of
the
diet,
0.16%.
Calorie
value
of
the
diet,
1571
kcal.
tThis
provided
the
daily
requirements
of
all
the
vitamins
as
recommended
by
the
National
Research
Council
(U.S.).
IOsborne
and
Mendel
salt
mixture.
66.
The
proteins
of
the
rice
diet,
or
the
same
supplemented
with
soya
flour
or
skim
milk
powder,
are
deficient
in
total
sulphur
amino
acids,
while
those
of
rice
diet
supplemented
with
methionine-fortified
soya
flour
are
deficient
in
tryptophan,
as
compared
to
FAO
reference
protein
or
Ideal
reference
protein
patterns.
Endogenous
Urinary
and
Faecal
Nitrogen
(Table
IV)
The
mean
daily
urinary
and
faecal
excretion
for
children
on
the
low-protein
diet
were
1.05
and
0.72
g
respectively.
PANEMANGALORE
ET
AL.:
RICE
DIET
645
TABLE
IV
Endogenous
nitrogen
excretion
(g/
day)
in
the
experimental
subjects
Girl
No.
Urinary
Faecal
Total
1
1.20
0.81
2.01
2
1.18
0.71
1.89
3
1.13
0.68
1.81
4
1.04
0.71
1.75
5
0.98
0.72
1.70
6
0.96
0.74
1.70
7
0.89
0.70
1.59
Mean
value
with
standard
error
(6
d.f.)
1.05±0.04
0.72±0.02
1.78±0.05
Nitrogen
Retention
(Table
V)
The
mean
daily
intake
of
nitrogen
on
the
different
diets
ranged
from
4.11
to
7.12
g.
The
nitrogen
balance
on
the
rice
diet
was
very
low
(20.3
mg/kg
day).
Supplementation
of
the
rice
diet
with
the
protein
supplements
resulted
in
a
considerable
increase
in
nitrogen
retention
(95.6-113.6
mg/kg
day).
The
retentions
of
nitrogen
on
rice
+
SF-Met
diet
and
rice
+
SMP
diet
were
nearly
the
same
(112.1
and
113.6
mg/kg
day)
and
significantly
higher
(P
<
0.01)
than
the
rice
+
SF
diet
(95.6
mg/kg
day).
Digestibility
Coefficient
and
Biological
Value
(Table
V)
The
true
digestibility
coefficients
of
the
proteins
in
the
different
diets
were:
rice
diet,
76.9;
rice
+
SF
diet,
85.6;
rice
+
SF-Met
diet,
85.5;
and
rice
+
SMP
diet,
87.1.
There
was
no
significant
difference
in
the
digestibility
coefficient
of
the
proteins
of
the
supplemented
diets.
The
biological
values
of
the
proteins
in
the
different
diets
were:
rice
diet,
68.0;
rice
+
SF
diet,
51.3;
rice
+
SF-Met
diet,
62.9;
and
rice
+
SMP
diet,
62.1.
The
biological
values
of
the
proteins
of
the
rice
+
SF-Met
diet
and
rice
+
SMP
diet
were
nearly
the
same
and
signifi-
cantly
higher
(P
<0.05)
than
that
of
rice
+
SF
diet.
Net
Protein
Utilization
(Operative)
(Table
V)
This
was
calculated
according
to
the
formula
of
Mitchell
(16).
As
pointed
out
by
Platt
et
al.
(17)
NPU
(0)
is
a
measure
of
the
nutritive
value
of
proteins
in
the
diet.
The
NPU
(0)
values
obtained
for
the
different
diets
(Table
V)
were
as
follows:
rice
diet,
52.3;
rice
+
SF
diet,
49.2;
rice
+
SF-Met
diet,
53.8;
and
rice
+
SNIP
diet,
54.1.
The
NPU
(0)
of
the
rice
+
SF-Met
diet
and
rice
+
SMP
diet
were
nearly
the
same
and
significantly
higher
(P
<
0.05)
than
that
of
rice
+
SF
diet.
Protein
Intake
and
Net
Available
Protein
(Table
VI)
The
mean
daily
protein
intake
and
net
available
protein
per
kilogram
body
weight
on
the
different
diets
were
as
follows:
rice
diet,
1.39
and
0.72
g;
rice
+
SF
diet,
2.37
and
1.17
g;
rice
SF-Met
diet,
2.41
and
1.29
g;
and
rice
+
SMP
C
A
NAD
IA
N
JOUR
NAL
OF
B
IOC
H
EM
IS
T
RY
.
VOL
.
42
,
1
96
4
TABLE
V
Mean
daily
balance
of
nitrogen
and
digestibility
coefficient
and
biological
value
of
proteins
of
the
different
diets
consumed
by
the
children
Diet*
N
intake
N
excretion
N
balance
True
diges-
tibility
(%)
Bio-
logical
value
NPU(
o
p
)
Urinary
(g)
Faecal
(g)
Total
(g)
g
mg/kg
%
in-
take
g
mg/kg
Rice
diet
4.11
222
2.06
1.68
3.74
0.37
20.3
9.0
76.7
68.2
52.3
Rice
+
soya
flour
7.03
380
3.56
1.74
5.30
1.73
95.6
24.7
85.4
58.3
49.9
Rice
+
methionine-
fortified
soya
flour
7.12
385
3.36
1.71
5.07
2.05
112.1
28.7
85.6
62.4
53.4
Rice
+
skim
milk
powder
7.12
385
3.40
1.65
5.05
2.07
113.6
29.2
86.9
62.2
54.0
Standard
error
of
the
mean
(18
d.f.)t
±0.074
dz5.01
±1.04
±1.20
±1.19
±1.10
*Calorie
value,
1571
kcal.
tObtained
from
the
analysis
of
variance
of
data
for
all
the
groups.
TABLE
VI
Mean
protein
intake
and
net
available
protein
in
children
on
different
diets
Diet
(%)
(%)
Rice
diet
7.06
3.69
Rice
diet
+
soya
flour
11.80
5.89
Rice
diet
methionine-
fortified
soya
flour
11.91
6.41
Rice
diet
+
skim
milk
powder
13.02
7.04
*(Protein
%
X
NPU)/100.
t(Protein
intake
X
NPU)/100.
IFAO
report
No.
16.
FAO,
Rome,
1957.
§M.
Swaminathan.
Indian
J.
Pediat.
30,
189
(1963).
of
protein
diet
value*
PAN
EMANGAL
O
RE
ET
AL
.:
RIC
E
DIET
Protein
intake
Net
available
proteint
Mini-
mum
(g/kg)
Opti-
mum
(g/kg)
Mini-
mum
(g/kg)
Opti-
mum
(g/kg)
g
g/kg
g
g/kg
25.7
43.9
44.5
44.5
1.39
2.37
2.41
2.41
13.4
21.6
23.9
24.1
0.72
1.17
1.29
1.30
0.60
0.90
0.64
0.96
FAO
reference
protein
Ideal
protein
Protein
Net
requirements
requirements§
content
dietary
TABLE
VII
Mean
daily
intake
and
absorption*
(mg/kg)
of
essential
amino
acids
by
the
children
from
the
different
diets
as
compared
with
amino
acids
requirements
Amino
acid
Diet
A
Diet
B
Diet
C
m
ka
e
nc
n
lii
t
d
nsot
take
Diet
D
require-
(mg/kg)
In-
take
Absorp-
tion
In-
Absorp-
tion
In-
take
Absorp-
tion
In-
take
Absorp-
tion
Arginine
78.2
59.9
154.0
131.7
156.0
134.2
115.3 100.3
Histidine
26.1
20.0
54.1
46.3
54.8
47.1
33.4
46.4
Lysine
59.4
45.51:
129.6
110.8
131.2
112.9
141.1
122.7
60.0
Leucine
115.0
88.1
191.7
164.0
194.2
167.0
217.3
189.1
45.0
Isoleucine
67.8
51.9
124.1
106.1
125.7
108.1
134.4
116.9
30.0
Methionine
23.2
17.8t
38.0
32.5
51.0
43.8
48.8
42.5
27.0
Cystine
17.8
13.6
35.8
30.6
36.3
31.2
26.9
23.4
Total
sulphur
amino
acids
41.0
31.4
73.8
63.1
87.3
75.0
75.7
65.9
-
Phenylalanine
75.8
58.1
126.0
107.7
127.6
110.0 126.0
109.6
27.0
Threonine
53.2
40.8
92.8
79.3
94.0
80.8
101.2
88.0
35.0
Tryptophan
13.2
10.1
26.1
22.3
26.4
22.7
28.1
24.5
9.0
Valine
89.7
68.7
140.3
120.0
140.2
122.2
161.1
140.0
33.0
*Calculated
as:
(intake
X
digestibility
coefficient
of
the
protein)/100.
(Data
of
Nakagawa
et
al.
(refs.
18-21).
Limiting
amino
acids.
c-,
oo
C
ANAD
IAN
JOU
RNAL
OF
B
I
OC
H
EM
IS
TRY
.
VOL
.
42
,
1
964
PANEMANGALORE
El'
AL.:
RICE
DIET
G49
diet,
2.41
and
1.30
g
respectively.
The
net
available
protein
on
the
rice
±
SF-Met
diet
and
rice
+
SNIP
diet
were
nearly
the
same
and
higher
than
on
the
rice
SF
diet.
The
net
available
protein
from
the
rice
diet
(0.72
g/kg)
did
not
meet
the
optimal
FAO
reference
protein
or
Ideal
protein
requirements
(0.90
and
0.96
g/kg
respectively),
while
the
rice
diet
supplemented
with
the
protein
foods
met
the
requirements.
Mean
Intake
and
Absorption
of
Essential
Amino
Acids
(Table
VII)
The
amount
of
essential
amino
acids
absorbed
was
calculated
as
(amino
acid
intake
X
digestibility
coefficient
of
the
protein)/100,
on
the
assumption
that
all
amino
acids
were
digested
and
absorbed
to
the
same
extent.
The
results
show
that
the
amounts
of
lysine
and
methionine
absorbed
from
the
rice
diet
were
lower
than
the
amino
acid
requirements
of
children
as
determined
by
Nakagawa
et
al.
(18-21).
All
the
supplemented
diets
met
the
amino
acid
requirements.
Discussion
Supplementation
of
a
rice
diet,
with
soya
flour,
methionine-fortified
soya
flour
or
skim
milk
powder
so
as
to
provide
about
1
g/kg
extra
protein
(N
X
6.25)
made
up
the
protein
deficiency
in
the
rice
diet
and
resulted
in
a
significant
(P
<
0.001)
increase
in
nitrogen
retention.
The
mean
retention
of
nitrogen
on
the
rice
diet
supplemented
with
methionine-fortified
soya
flour
or
skim
milk
powder
was
nearly
the
same
and
significantly
(P
<
0.01)
higher
than
that
observed
with
a
diet
supplemented
with
soya
flour.
This
may
be
due
to
the
fact
that
the
proteins
of
soya
flour
contribute
lesser
amounts
of
sulphur
amino
acids
than
does
skim
milk
powder
or
methionine-fortified
soya
flour.
The
biological
value
and
net
protein
utilization
of
the
mixed
proteins
of
rice
SNIP
diet
and
rice
SF-Met
diet
are
also
nearly
the
same
and
significantly
(P
<
0.05)
higher
than
that
of
rice
SF
diet.
The
results
show
that
methionine-fortified
soya
flour
compares
favorably
with
that
of
skim
milk
powder
and
is
significantly
superior
to
soya
flour
in
supplementing
rice
diet.
The
results
presented
in
Table
VI
show
that
the
net
available
protein
from
the
rice
diet
(0.72
g/kg)
did
not
meet
the
requirements
of
FAO
reference
pro-
tein
(0.90
g/kg)
or
Ideal
reference
protein
(0.96
g/kg)
;
on
the
other
hand
the
net
available
protein
from
the
diets
supplemented
with
the
protein
foods
met
the
protein
requirements.
Also
the
amounts
of
lysine
and
methionine
absorbed
from
the
rice
diet
were
lower
than
the
amino
acid
requirements
of
children
as
determined
by
Nakagawa
et
al.
(18-21).
The
rice
diet
supplemented
with
the
protein
foods
met
the
amino
acid
requirements.
It
may
be
concluded
from
the
results
obtained
in
the
present
investigation
that
in
regions
where
milk
is
in
short
supply,
processed
soya
flour
can
be
used
as
a
supplement
for
overcoming
the
many
deficiencies
of
proteins
and
other
dietary
essentials
of
the
vulnerable
sections
of
the
population.
Somewhat
better
results
are
obtained
if
fortification
with
methionine
is
included.
650
CANADIAN
JOURNAL OF
BIOCHEMISTRY.
VOL.
42,
1964
Acknowledgments
Our
thanks
are
due
to
Dr.
V.
Subrahmanyan
for
his
keen
interest
in
the
work.
References
1.
FAO.
Production
Year
book.
Vol.
12.
Food
Agr.
Organ.
U.N.,
Rome.
1958.
2.
V.
SUBRAHMANYAN,
M.
NARAYANA
RAO,
and
M.
SWAMINATHAN.
Proc.
Natl.
Inst.
Sci.
India,
PA
26,
Suppl.
1,
99
(1960).
3.
N.
S.
SCRIMSHAW
and
R.
BRESSANI.
Federation
Proc.
20,
Suppl.
7,
80
(1961).
4.
M.
AUTRET
and
A.
G.
VAN
VEEN.
Am.
J.
Clin.
Nutr.
3,
234
(1955).
5.
N.
S.
SCRIMSHAW.
J.
Am.
Dietet.
Assoc.
35,
441
(1959).
6.
S.
KUPPUSWAMY,
M.
SRINIVASAN,
and
V.
SUBRAHMANYAN.
Proteins
in
Foods.
Special
Rept.
No.
33.
Indian
Council
of
Medical
Research,
New
Delhi.
1958.
7.
K.
JOSEPH,
M.
NARAYANA
RAO,
M.
SWAMINATHAN,
K.
INDIRAMMA,
and
V.
SUBRAHMAN-
VAN.
Ann.
Biochem.
Exptl.
Med.
Calcutta,
20,
243
(1960).
8.
H.
S.
R.
DESIKACHAR,
S.
S.
DE,
and
V.
SUBRAHMANYAN.
Ann.
Biochem.
Exptl.
Med.
Calcutta,
6,
57
(1946).
9.
M.
L.
ANSON.
J.
Gen.
Physiol.
22,
79
(1938).
10.
K.
JOSEPH,
P. P.
KURIEN,
M.
SWAMINATHAN,
and
V.
SUBRAHMANYAN.
Brit.
J.
Nutr.
13,
213
(1959).
11.
S.
K.
REDDY,
T.
R.
DORAISWAMY,
A.
N.
SANKARAN,
M.
SWAMINATHAN,
and
V.
SUBRAH-
MANYAN.
Brit.
J.
Nutr.
8,
17
(1954).
12.
K.
KRISHNAMURTHY,
P.
K.
TASKER,
T.
N.
RAMAKRISHNAN,
R.
RAJAGOPALAN,
and
M.
SWAMINATHAN.
Ann.
Biochem.
Exptl.
Med.
Calcutta,
20,
73
(1960).
13.
FAO.
Nutr.
Studies.
Protein
requirements,
Food
Agr.
Organ.
U.N.,
Rome,
16,
(1957).
14.
M.
SWAMINATHAN.
Indian
J.
Pediat.
30,
189
(1963).
15.
H.
N.
PARTHASARATHY,
T.
R.
DokAlswAmv,
M.
PANEMANGALORE,
M.
NARAYANARAO,
B.
S.
CHANDRASEKHAR,
M.
SWAMINATHAN,
A.
SREENIVASAN,
and
V.
SUBRAHMANYAN.
Can.
J.
Biochem.
42,
377
(1964).
16.
H.
H.
MITCHELL.
Record
Proc.
Soc.
Animal
Production,
55
(1922).
17.
B.
S.
PLATT,
D.
S.
MILLER,
and
P.
R.
PAYNE.
In
Recent
advances
in
human
nutrition
with
special
reference
to
clinical
medicine.
J.
F.
Brock
(Editor).
J.
A.
Churchill
Ltd.,
London.
1961.
p.
351.
18.
I.
NAKAGAWA,
T.
TAKAHASHI,
and
T.
SUZIKI.
J.
Nutr.
71,
176
(1960).
19.
I.
NAKAGAWA,
T.
TAKAHASHI,
and
T.
SUZIKI.
J.
Nutr.
73,
186
(1961).
20.
I.
NAKAGAWA,
T.
TAKAHASHI,
and
T.
SUZIKI.
J.
Nutr.
74,
401
(1961).
21.
I.
NAKAGAWA,
T.
TAKAHASHI,
T.
SUZIKI,
and
K.
KOBAYASHI.
J.
Nutr.
77,
61
(1962).