Biological Evaluation of a Nutritional Supplement Prepared with QPM Maize Cultivar BR 473 and other Traditional Food Items

247
Vol.47, n. 2 : pp. 247-251, June 2004

BRAZILIAN ARCHIVES OF
ISSN 1516-8913 Printed in Brazil
BIOLOGY AND TECHNOLOGY


A N I N T E R N A T I O N A L J O U R N A L



Biological Evaluation of a Nutritional Supplement Prepared
with QPM Maize Cultivar BR 473 and other Traditional
Food Items

Heberth de Paula1?, Rinaldo C. Santos2, Marcelo E. Silva2, Enara C. S. Glória2, Maria
Lúcia Pedrosa3, Nízia A. V. Almeida4, Alexandre S. V. Costa5 and Luiz Cosme C.
Malaquias5
1 Departamento de Alimentos; Escola de Nutrição; 2 Departamento de Ciências Biológicas; 3 Universidade Federal
de Ouro Preto; 35400-000; Ouro Preto - MG - Brazil. 4 Secretaria Municipal de Educação de Governador
Valadares; Secretaria Municipal de Saúde de Governador Valadares. 5 Universidade do Vale do Rio Doce -
UNIVALE; Vale do Rio Doce - MG - Brazil


ABSTRACT

Quality Protein Maize (QPM) cultivar BR 473 was employed, together with soybean flour, brown sugar, banana
meal and oat meal, for the preparation of a nutritional supplement.. 21-day old male Fisher rats were fed diets
containing the supplement as a protein source, both with and without soybean flour; casein diets with 10 or 7%
protein served as respective controls. Protein Efficiency Ratio (PER), Net Protein Utilization (NPU), Net Protein
Retention (NPR) and Digestibility were determined. Blood biochemical parameters (glucose, cholesterol, urea,
hemoglobin, albumin and total protein) were also measured in the animals and showed that all were in good health
condition at the end of the experiment. The obtained results for PER, NPU and NPR indicated that the supplement
prepared with QPM maize cultivar BR 473 was a good protein source, especially when soybean flour was added.

Key words: QPM Maize, protein, biological evaluation, nutritional supplement


INTRODUCTION
organisms (Torin et al., 1995; Amaya-Farfán,

1998; Tramonte, 2000). In this context, the search
The prevalence of malnutrition among low income
for supplements using traditional and nutritive but
populations in Brazil has led to the utilization of
low cost foods is under way.
“alternative” food ingredients, such as powdered
Quality protein maize (QPM) is one of these foods
cassava and sugar beet leaves, wheat and rice bran
(Paes and Bicudo, 1995). Cultivar BR 473,
and powdered egg shell, among others, as
developed by Brazilian Enterprise of Agricultural
nutritional
supplements
(Santos,
2001).
Research (EMBRAPA), contains 9.04% protein,
Nevertheless the results obtained are highly
4.44% fat, 0.40% fiber, 75.3% carbohydrate,
disputed,
both
in
the
practical
and
the
0.59% minerals and is rich in lysine (0.40%) and
experimental fields and antinutritional factors are
tryptophan (0.09%) (Paes, 1994). It is employed in
believed to play important roles in the absortion
the preparation of a nutritional supplement,
and/or utilization of nutrients by the target
together with soybean flour, brown sugar, banana

? Author for correspondence
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248
Paula, H. et al.
meal and oat meal, utilized in the project
work aimed at evaluating biologically this
“Production and consumption of QPM BR 473
supplemnt in diets both with and without the
maize in the recovery of malnourished children in
addition of soybean flour and comparing their
the municipality of Governador Valadares”,
protein quality with that of casein diets with
carried out by local authorities, University of Vale
similar protein contents.
do Rio Doce and Pastoral da Criança. The present

Table 1 - Composition of the QPM BR 473 supplements with (A) and without (B) soybean flour (values in % w/w)
Ingredients
A
B
QPM BR 473 whole flour
45
60
Soybean flour
15
00
Brown sugar
10
10
Banana meal
20
20
Oat meal
10
10
Total
100
100



Table 2 - Composition of the diets (% w/w). (A) Control 10%; (B) Control 7%; (C) Protein-free; (D) Experimental
with Soybean flour; (E) Experimental without Soybean flour.
Ingredients
A
B
C
D
E
Casein1
12.50
8.75
-
-
-
Salt mixture2
5.0
5.0
5.0
5.0
5.0
Vitamin mixture2
1.0
1.0
1.0
1.0
1.0
Soybean oil
8.0
8.0
8.0
6.0
6.0
Choline
0.04
0.04
0.04
0.04
0.04
Cellulose
1.0
1.0
1.0
1.0
1.0
Corn starch
72.46
76.21
84.96
11.21
-
Supplement
-
-
-
75.75
86.96
1 Casein contained 80,0% w/w protein
2 According to AOAC, 1975



Table 3 - Chemical composition of the diets (% w/w). (A) Control 10%; (B) Control 7%; (C) Protein-free; (D)
Experimental with Soybean flour; (E) Experimental without Soybean flour

A
B
C
D
E
Protein
10,22
7,23
0,25
9,65
6,62
Ashes
5,36
5,28
5,08
6,88
6,69
Fat
8,01
8,01
8,00
7,30
7,31
Moisture
10,64
10,58
10,20
6,83
6,66
Carbohidrate
64,76
67,89
75,46
68,14
71,47
Fiber
1,01
1,01
1,01
1,20
1,25


MATERIALS AND METHODS
approximately isocaloric and the protein contents

of the control diets were in consonance with those
Nutritional
supplements
-
The
proposed
of the experimental ones, that is 10 and 7% w/w
supplements were prepared by mixing thoroughly
were controls for respective experimental diet with
its ingredients and their composition is shown in
soybean flour and experimental without it. The
Table 1.
chemical composition of the diets is shown in
Animals and diets - 21-day old male Fisher rats
Table 3.
were divided randomly into five groups of 20
Biological assay - Biological parameters were
animals each, housed in individual wire cages and
determined as described by Pellet and Young,
fed the diets shown in Table 2; diets were
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Biological Evaluation of a Nutritional Supplement Prepared with QPM Maize Cultivar BR 473
249
(1980). Food consumption and weight gain by the
RESULTS
animals were recorded weekly.

Net protein utilization (NPU) was calculated by
Data relative to food ingestion, weight gain and
the difference in carcass nitrogen (as expressed by
feces weight are depicted in Table 4. Animals fed
nitrogen in left hind leg) between rats fed the test
the diets containing the supplements, both with
diets and those fed a protein-free diet. After 10
and without soybean, ingested as much food as did
days of experiment, half of the rats were sacrificed
the control 10% protein group and a bit more than
and the left hind leg was excised and weighed.
the 7% protein controls. On the other hand, weight
Nitrogen was determined. The following equation
gain was statistically similar when experimental
was used for NPU evaluation:
groups were compared with their respective

controls. Nevertheless, when food efficiency
NPU = [N in carcass (test group) - N in carcass
(weight gain/food ingestion) was considered,
(protein-free group)]/ N ingested by test group
animals receiving the supplements showed values

comparable to their respective controls (24.2%,
Net protein ratio (NPR) was calculated by the
21.9%, 14.8% and 11.7%, respectively for control
difference in body weight changes between the test
10%, experimental with soybean, control 7% and
group and the protein-free group, using the
experimental without soybean) The amount of
following equation:
feces excreted by animals that ingested the diets

containing the supplements was higher than their
weight g
ain (
test g
roup
)
+ weight l oss ( protein - free g
roup)
NPR
=
respective controls.
protein i
ngested b
y test g
roup
In Table 5 are shown the figures obtained when

protein quality was biologically assessed. PER
Protein efficiency ratio (PER) was calculated by
values were similar for all groups, except for the
the ratio of weight gain(g)/protein intake (g), after
one fed the diet containing supplement without
28 days for each of the remaining animals.
soybean flour. On the other hand, rats on all diets
Digestibility (D); From the 14th to the 21st day of
presented statistically equal values for NPU. In
experiment, the feces were collected daily, dried at
relation to NPR, animals receiving the diet made
105º C, weighed and its nitrogen content
employing the supplements with or without
determined. D was evaluated through the
soybean flour showed patterns statistically similar
following equation:
to their respective (10 and 7 % protein) controls.

As regards the digestibility, casein diets were
nitrogen i
ntake -
fecal n
itrogen

D
=


×10
0
statistically similar to each other and same
nitrogen i
ntake
happened with the experimental diets.

Table 6 shows the biochemical characteristics
Biochemical determinations - Blood cholesterol,
found in the blood of the animals fed with various
glucose, albumin, urea, total protein and
diets. As seen, values were statistically similar in
hemoglobin were determined with commercial kits
all parameters, except for hemoglobin, which was
(Labtest Diagnóstica S. A., Lagoa Santa, Minas
slightly higher in the group that received diet
Gerais, Brazil).
containing supplement with soybean flour as

compared to its control (10 % protein).
Statistical analysis - All results were submitted to

analysis of variance using the software EPISTAT
( T. L. Gustafson, Round, Tx, EUA)

Table 4 - Food ingestion, weight gain and feces weight of animals fed control 10% (A), control 7% (B), Protein-free
(C), Experimental with Soybean Flour (D) or Experimental without Soybean flour (E) diets1,2

A (g)
B (g)
C (g)
D (g)
E (g)
Food ingestion
326.5±21.8a
276.0±41.5b
217.4±7.8c
356.0±41.4a
324.7±9.2a
Weight gain
79.0±9.3a
41.0±13.1b
17.4±4.6c
78.7±9.7a
38.4±5.8b
Feces weight
14.5±1.6a
12.0±1.9a
3.7± 0.4d
53.8±6.3b
43.8±3.9c
1 Mean ± standard deviation indicated
2 Different superscript letters in the same line indicate significant difference (p<0.05)

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250
Paula, H. et al.
Table 5 - Protein efficiency ratio (PER), net protein utilization (NPU), net protein ratio (NPR) and digestibility (D)
of animals fed control 10% (A), control 7% (B), Experimental with Soybean Flour (D) or Experimental without
Soybean flour (E) diets1,2

A
B
D
E
PER
2.41± 0.17a
2.10± 0.58a
2.21± 0.11a
1.69± 0.25b
NPU
102.28± 2.97a
114.18±29.63a
94.86± 5.52a
95.12± 4.64a
NPR
3.96± 0.48a
2.69± 1.36b,c
3.77± 0.42a,c
1.89± 0.53b
Digestibility
91.8± 0.7a
91.3± 1.5a
72.3± 2.8b
69.3± 14.1b
1 Mean ± standard deviation indicated
2 Different superscript letters in the same line indicate significant difference (p<0.05)


Table 6 - Blood biochemical parameters of animals fed control 10% (A), control 7% (B), Protein-free (C),
Experimental with Soybean Flour (D) or Experimental without Soybean flour (E) diets1,2

A
B
C
D
E
R. V.3
Cholesterol(mg/dL)
59.35±24.75a
63.40±12.44a
44.22±24.62a
67.64±8.42a
67.71±8.59a
27 (10-54)
Glucose (mg/dL)
139.33±59.06a 133.20±13.89a 139.01±16.48a 152.54±12.14a 141.34±11.92a
75 (50-135)
Albumin (g/dL)
3.22±1.31a
3.31± 0.39a
2.89± 0.18a
3.13± 0.27a
2.81± 0.24a
3.7 (2.7-5.1)
Urea (mg/dL)
34.91±15.57a
29.66±2.14a
29.40±3.89a
28.70±2.62a
27.48±3.66a
31(10.7-62.1)
Total protein(g/dL)
5.25± 2.19a
5.13± 0.32a
4.90± 0.54a
5.38± 0.46a
5.00± 0.22a
7.6 (4.7-8.2)
Hemoglobin (g/dL)
12.83±1.26a
14.27±1.03a,b 13.54±0.58a,b
14.31±0.79b
13.65±0.91a,b
14.2 (11-17)
1 Mean ± standard deviation indicated
2 Different superscript letters in the same line indicate significant difference (p<0.05)
3 Reference values, CCAC, 1984: average value (range)


DISCUSSION
When nutritional indexes were investigated (Table

5), it was seen that QPM maize contributed for the
The use of food supplements made with alternative
improvement of protein quality of the supplement.
ingredients, such as used in this study, in the
NPU values were statistically similar in all cases.
recovery of malnourished children is controversial.
PER values did not differ statistically, except for
Câmara and Madruga (2001) did not find
animals ingesting the diet containing the
significant levels of toxic or antinutritional factors
supplement without soybean. It must be stressed
in a supplement made with alternative ingredients,
that the effect of soybean flour addition was
the so called “multimistura”. On the other hand,
relevant, since this item represented only about
biological assays with rats didn’t show any
11% w/w of the diet but raised the PER value in
advantages in its utilization (Boaventura et al.,
about 30%. This effect was confirmed by NPR
2000; Melo et al., 2000; Tramonte et al., 2000). If
that, taking into account the weight loss by the
one agrees that using low cost and nutritive
non-protein group, made similar the values of the
supplements is an important tool in the recovery or
experimental animals with their respective
maintenance of good nutritional status in low
controls. As expected, the digestibilities of the 10
income populations QPM maize, with or without
and 7% control diets were similar to each other but
soybean flour, could be worth evaluation.
higher then that of the experimental ones, probably
The weekly recording of food consumption and
due to the fiber content of maize, banana and oat
weight gain showed that the biological assay
employed in the preparation of the supplements
proceeded without abnormalities. As can be learnt
(Eggum 1995).
from Table 4, food efficiency of the diets
Assessment of blood biochemical parameters of the
containing the proposed supplements was similar
animals on the various diets (Table 6) showed their
to their respective controls. As expected, feces
general health status; all of them presented
weight was dependent on the amount of fiber in
statistically similar values for cholesterol, glucose
the diets (Table 3) and on food ingestion (Table 4),
and urea. When parameters more linked to protein
with the animals consuming the diet with soybean
metabolism (albumin, total protein and hemoglobin)
flour showing the highest value.
were considered, it was seen that statistical
differences were detected only in relation to
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Biological Evaluation of a Nutritional Supplement Prepared with QPM Maize Cultivar BR 473
251
hemoglobin, although all values fell within the
Câmara, F. S. and Madruga, M. S. (2001), Cyanic acid,
range acceptable for the rat (CCAC, 1984).
phytic acid, total tannin and aflatoxin contents of a
In conclusion, the results obtained in the present
brazilian (Natal) multimistura preparation. Rev. Nutr.,
work indicated that QPM maize BR 473 showed a
14 : (1), 33-36.
Canadian Council on Animal Care - CCCA (1984),
good potential for utilization in nutritional
Guide to the care and use of experimental animals
supplements, especially when associated with
Otawa. pp. 85-88.
soybean flour.
Eggum, B. O. (1995), The influence of dietary fibre on

protein digestion and utilization in monogastrics.

Arch. Tierernahr., 48, 89-95.
RESUMO
Melo, S. S. et al. (2000), Efeito da multimistura no

crescimento e desenvolvimento de ratos desnutridos e
Milho de Qualidade Protéica (QPM) da cultivar
eutróficos. Paper presented at Simpósio Sul-Brasileiro
BR 473, desenvolvida pela EMBRAPA está sendo
de Alimentação e Nutrição. História, Ciência e Arte.
Florianópolis, 26-28 April. pp. 251-255.
empregado, juntamente com farinha de soja,
Paes, M. C. D. (1994), Perspectivas nutricionais do
açúcar mascavo, farinha de banana e farinha de
milho de alta qualidade protéica. Sete Lagoas :
aveia,
na
preparação
de
um
suplemento
EMBRAPA - Centro Nacional de Pesquisa de Milho
nutricional, usado na recuperação de crianças
e Sorgo.
desnutridas
no
município
de
Governador
Paes, M. C. D. and Bicudo, M. H. (1995), Nutritional
Valadares, MG. Reporta-se aqui o resultado da
Perspectives of Quality Protein Maize. In: Larkins, B.
avaliação biológica deste suplemento. Ratos Fisher
A. and Mertz, E. T. (eds.). Quality Protein Maize:
machos de 21 dias de idade foram alimentados
1964-1994.
Proceedings
of
the
International
com dietas contendo o suplemento como fonte de
Symposium on Quality Protein Maize. Sete Lagoas.
proteína, com ou sem farinha de soja; dietas de
pp. 65-78.
Pellet, P. L. and Young, V. R. (1980), Evaluation of
caseína com 10 ou 7% de proteína serviram como
protein quality in experimental animals. In:
respectivos controles. Foram determinadas a
Nutritional Evaluation of Protein Foods. Tokio : The
Razão de Eficiência Protéica (REP), a Utilização
United Nations University. pp. 41-57.
Líquida de Proteína (ULP), a Razão Líquida de
Santos, L. A. S. et al. (2001), Uso e percepções da
Proteína (RLP) e a Digestibilidade. Parâmetros
alimentação alternativa no estado da Bahia: um
bioquímicos sanguíneos (glicose, colesterol, uréia,
estudo preliminar. Rev. Nutr., 14 : (supl.), 35-40.
hemoglobina, albumina, e proteína total) foram
Torin, H. R et al. (1995), Alimentação alternativa:
também medidos nos animais e mostraram que
posição da Sociedade Brasileira de Pediatria. Jornal
todos estavam em boas condições de saúde ao
de Pediatria, 71 : (4), 235-236.
final do experimento. Os resultados obtidos para
Tramonte, V. L. C. G. et al. (2000), Efeito de uma
multimistura como fonte de vitaminas para ratas
REP, ULP, RLP e Digestibilidade indicam que o
lactantes e seus reflexos sobre o peso da prole. Paper
suplemento preparado com o milho QPM cultivar
presented at Simpósio Sul-Brasileiro de Alimentação
473 é uma boa fonte de proteína, especialmente
e Nutrição. História, Ciência e Arte. Florianópolis,
quando a farinha de soja é adicionada.
26-28 April. pp. 257-261.

Tramonte, V. L. C. G. (2000), Multimistura x

estratégias alimentares: uma avaliação científica.
REFERENCES
Paper presented at Simpósio Sul-Brasileiro de

Alimentação e Nutrição. História, Ciência e Arte.
Amaya-Farfán, J. (1998), Alimentação alternativa:
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análise crítica de uma proposta de intervenção

nutricional. Cad. Saúde Públ., 14 : (1), 201-212.

AOAC (1975), Official Methods of Analysis,.
Received: July 04, 2002;
Revised: October 09, 2002;
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of
Official
Analytical
Chemists,
Accepted: September 19, 2003.
Washington, D.C.

Boaventura, G. T. et al. (2000), Avaliação biológica da
multimistura. Paper presented at Simpósio Sul-
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