Edited by: Tecnológico Superior
Corporativo Edwards Deming
July - December Vol. 6 - 2 - 2022
e-ISSN: 2576-0971
Received: 09 November, 2021
Approved: January 04, 2022
Page 77-90
Effect of partial substitution with precooked rice
and amaranth flours on the technological and
nutritional characteristics of bread
Efecto de la sustitución parcial con harinas precocidas de
arroz y amaranto sobre las características tecnológicas y
nutricionales del pan
Carmen Llerena R
Jessenia Ávila López*
Gabriela Suárez Gómez*
Karla Miranda Ramos*
Developing innovative products by rescuing ancestral raw
materials with high nutritional value is a challenge for
researchers; the objective of this research was to develop
breads with high nutritional quality by partially substituting
wheat flour with precooked amaranth and brown rice
flour. To establish the formulations, the Design Expert Ver
8.0 software was used; the substitution levels cover a range
from 5% to 30%; the sponge method was used because it
offers better crumb quality. Bread quality was analyzed in
terms of chemical composition, specific bread volume,
width/height ratio of the central slice, crumb structure and
firmness, and sensory analysis. Starch thermal properties
were studied in terms of starch hydration properties. The
incorporation of the flour blend increased protein, lipid,
fiber, ash and myoinositol phosphate contents. The best
mixture contains 20% amaranth and 10% brown rice, the
bread obtained has a soluble/insoluble fiber ratio close to
1:2, which presents the most effective physiological action
* Dra. En Ciencias Alimentarias, Universidad de Guayaquil, carmen.llerenar@ug.edul.ec,
* Ingeniera Química, Universidad de Guayaquil, jessenia.avilal@ug.edu.ec,
* Ingeniera Química, Universidad de Guayaquil, gabirela.suarezgl@ug.edu.ec,
* Master en Calidad y Producción, Universidad de Guayaquil,
karla.mirandar@ug.edul.ec, https://orcid.org/0000-0003-0265-6348
Tecnológico Superior Corporativo Edwards Deming Vol. 6 - 2 - 2021 https://revista-edwardsdeming.com/index.php/es
e-ISSN: 2576-0971
and has a protein content that could cover the protein
requirement in adults.
Keywords: bakery, amaranth, brown rice
Desarrollar productos innovadores rescatando materias primas ancestrales con alto
valor nutricional es un reto para los investigadores, el objetivo de esta investigación fue
desarrollar panes con alta calidad nutricional mediante la sustitución parcial de harina de
trigo por harina precocidas de amaranto y arroz integral. Para establecer las
formulaciones se utilizó el software Design Expert Ver 8,0, los niveles sustitución cubren
un rango del 5% hasta el 30%, el método esponja se empleó porque ofrece mejor calidad
de miga. La calidad del pan se analizó en términos de composición química, volumen
específico del pan, relación ancho/alto de la rebanada central, estructura y firmeza de la
miga y análisis sensorial. Las propiedades térmicas del almidón se estudiaron en función
de las propiedades de hidratación del almidón. La incorporación de la mezcla de harina
incrementó los contenidos de proteína, lípidos, fibra, cenizas y fosfato de mioinositol. La
mejor mezcla contiene 20% de amaranto y 10% de arroz integral, el pan obtenido
presenta una relación de fibra soluble/insoluble cercanas a 1:2, lo que presenta la acción
fisiológica más efectiva y presenta un contenido de proteína que podría cubrir el
requerimiento proteico en adultos.
Palabras clave: panificación, amaranto, arroz integral
Wheat bread is a food widely consumed by the population. Wheat flour is used to make
this type of bakery product, but in Ecuador the wheat harvest is not sufficient to meet
the country's needs, so about 98% of wheat is imported. This is used for its gluten
content, which gives the dough resistance and elasticity, leaving behind several cereals
such as corn, rice, oats, etc., but it has a low level of essential amino acids such as lysine
and threonine, as well as low fiber content. Recent studies seek to improve these
nutritional characteristics by incorporating other ingredients into the baking process.
(Salas & Haros, 2016). The nutritional properties of grains such as amaranth, quinoa,
brown rice and other grains as a source of dietary fiber, proteins, bioactive compounds,
whose lysine concentration is considerably higher than that of wheat flour, help to
prevent diseases associated with the syndrome. (Mesas & Alegre, 2002)They help
prevent diseases associated with metabolic syndrome such as cardiovascular diseases,
arteriosclerosis and colon cancer. (Marianda, Ponce, & Haros, 2019)..
The benefits from the consumption of precooked brown rice (Oryza sativa L.), due to
its fiber content is interesting, it has a low content of prolamins, low sodium content,
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e-ISSN: 2576-0971
high content of digestible carbohydrates and high rate of protein, which are mostly
composed of albumins, globulins, and has a higher content of lysine than polished rice
because this amino acid is present in the outer layers of the grain, compared to polished
and processed white rice. The proportion of essential amino acids with respect to total
amino acids is 41%, being recommended that this ratio is approximately 36%, being found
that this cereal exceeds the established by FAO. (Salas & Haros, 2016). From a food
safety perspective, brown rice has been recognized by FAO as an important part of the
human diet.
Pseudo cereals are widely used in the diet of the ancient inhabitants of America, for this
reason in Ecuador the Andean crops program of INIAP have developed an improved
variety INIAP - Alegria (Amaranthus caudatus), which is a white seed very popular among
consumers. Amaranth has important nutritional properties in its seed components;
about 16% of high quality proteins (such as globulin) are rich in lysine and sulfur amino
acids, these are essential for optimal nutrition due to their excellent amino acid balance,
as they provide 16.6% lysine, which is a higher percentage than traditional cereals such
as wheat, which according to Gil (2010) has 2.5%. (Galarza, I, & Falcón, 2013)In addition,
amaranth contains lipids between 7 to 8%, of which squalene is a powerful antioxidant
and strengthener of the immune system, it also contains unsaturated fatty acids, such as
linoleic acid, and minerals such as sodium, potassium, calcium, magnesium, copper,
manganese, nickel and iron. (Matias, et al., 2018). It also contains thiamine, riboflavin,
niacin and when germinated it contains vitamin A and C. (Alvarez, Gallagher, Reguera,
& Haros, 2009)For this reason, this seed has achieved a growing interest as a functional
ingredient due to its nutritional and technological properties, especially in baking
processes, and because it is very versatile for processing and industrialization. (Penella,
Wronkowska, Smietana, & Haros, 2013). Because of its characteristic texture (gummy),
amaranth, like quinoa, is more difficult to eat in large quantities, for this reason it is
better to use it in the form of pre-cooked flour, combining this flour in the elaboration
of cookies, cookies, tortillas, etc. Although sensory acceptance may decrease with
A widely employed practice to improve nutritional quality is the fortification of flours,
which is defined by the standard ( NTE INEN 616, 2016) as a diet-based preventive
strategy designed to increase the value of micronutrients, and which can be included in
the framework of other interventions designed to reduce vitamin and mineral
deficiencies to prevent or correct one or more demonstrated nutrient deficiencies in
the population. Many studies have been conducted to improve the nutritional value of
bread by partially replacing wheat flour with other flours; some researchers suggest
adding whole wheat grains, wheat bran, grains of other cereals or pseudocereals such as
amaranth, quinoa, rice to bakery products up to a maximum of 30%. (Pilataxi, 2013)The
use of amaranth often contains anti-nutrients such as phytic acid (myoinositol
(1,2,3,4,5,6)-hexakisphosphate, InsP6) or its salts, phenolic compounds, and trypsin
inhibitors. (D'Amico, Schoenlechner, Tömösközia, & Langó, 2020). Phytic acid has
negative health effects because it inhibits the availability of minerals. (Penella-Sanz, 2013).
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e-ISSN: 2576-0971
Phytate content in Amaranthus spp. has been found to range from 4.8 to 21.1 μmol/g.
(Reguera & Haros, 2017). However, several studies have suggested that this compound
has favorable effects, such as antioxidant function, prevention of heart disease, and anti-
carcinogenic effect, which it performs through its hydrolysis products (Haros, et al.,
2009); (Kumar, Sinha, Makkar, & Becker, 2010). Recent studies show substitution of
wheat flour up to a level of 25% or in specific breads without fermentation. (Kamoto,
Kasapila, & Manani, 2018)or in specific breads without fermentation (Banerji,
Ananthanarayan, & Lele, 2018). The purpose of this research is to develop bread with
higher nutritional value, with good technological and sensory quality.
Commercial whole wheat flour brand "La Cordillera", the variety used was hard red
spring wheat, precooked amaranth flour brand "Zangur", of the species Amaratus
caudatus, precooked brown rice flour brand "Portilla". The variety used was INIAP 17.
For flour processing according to the methodology of Altamirano, 2017, brown rice
samples are subjected to a process of soaking in water at 60°C for 45 minutes and
precooked at 75°C for 6 minutes, with the same ratio water - rice (1:1) (Altamirano,
Ortola, & Castello, 2017). Then, the drying process of the samples is carried out at 60°C,
described by (Santamarìa, 2017) The samples are then dried at 60°C in a "LINDBERG
BLUE "GO1390A-1" oven. For the preparation of the samples, the grains were milled in
a conventional mill to obtain rice flour. According to the standard ( NTE INEN 3050,
2016) the particle size of the rice flour must be passed through a 250 μm sieve.
The formula for the bread dough expressed based on flour consisted of different
formulations of flour (500 g), fresh yeast of commercial brand "Levapan", sodium chloride,
salt of commercial brand "Cris-Sal", fat of commercial brand "Bonella", sugar of
commercial brand "San Carlos", eggs and improver of commercial brand "Propastel".
(Silva, 2016)sugar, "San Carlos" brand sugar, eggs and "Propastel" brand improver were
used. The average weight of the bread is 50g.
To carry out the experimental design of flour substitution mixtures, the Design Expert
software version 8.0 was used, choosing the Optimal factorial design (custom) to have a
model that adapts to the established conditions, depending on the maximum range to be
able to substitute, the dough with 100% wheat flour was used as a control sample and
the bread dough was also made using the precooked rice and amaranth flours at 100%.
The sponge method was used for which the dough was made in two stages according to
the methodology described by. (Iglesias-Puig, Monedero, & Haros, 2015). Finally, the
samples were baked at 170 °C/20 min. The breads were cooled at room temperature
for 2 h for subsequent analysis. (Sanz-Penella, Tamayo-Ramos, Sanz, & Haros, 2013)..
Moisture was determined by a gravimetric method. (NTE-INEN 518, 1980-12)The ash
content was determined in a muffle by incineration at 900 °C (AOAC 923.03, 2005) v,
protein determination was carried out by the Kjeldahl technique, lipids were determined
by a gravimetric method. (AOAC 2001.11, 2001)lipids were determined by extraction
under petroleum ether reflux conditions by the Soxhlet technique, and dietary fiber
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e-ISSN: 2576-0971
content was determined by the Kjeldahl technique. (AOAC 945.16, 1990) technique, and
dietary fiber content was measured by (AOAC 2011.25, 2011).
Calcium, iron and zinc concentrations were determined in the selected mixtures using
for calcium, iron and zinc, which were determined by atomic absorption with Spectra
model 220 (AOAC 985.35, 2016)and zinc, which were determined by atomic absorption
with Spectra model 220 Fast sequential equipment with zinc lamp (AOAC 985.35, 2005)
and with iron lamp (AOAC , 1999).
Technological characteristics of bread
The technological parameters analyzed were the following: specific bread volume (cm3
/g) by volume measurement (cm3) by seed displacement (volume-meter, Chopin, France)
and weight (g), width/height ratio of the central cut (cm/cm).
For the crumb, digital image analysis was used to measure breadcrumb structure. Images
were pre-fronted at 240 pixels per cm with a flatbed scanner (Epson ScanJet L375.) and
support by Image J 3.1 Software. A 10 mm × square field of view of two central slices (10
mm thick), thus producing 2 digital images per treatment. The data was processed using
Image J Image Analysis Software (version 5.0.0), The crumb grain features chosen were
evaluated by the number of cells per cm2; and Cell Mean Area, μm2 (Sanz-Penella,
Tamayo-Ramos, Sanz, & Haros, 2013). The texture of the selected formulation was
evaluated by sensory testing and the following parameters were evaluated: relative
firmness, elasticity, cohesiveness, (Haros, Rosel, & Bebedito, 2002)..
Preliminary sensory analysis of fresh breads was conducted by a panel of 90 untrained
tasters who typically consume wheat bread, using about nine hedonic scale points of
overall acceptability (Iglesias-Puig, Monedero, & Haros, 2015)..
Fisher's least significant and multiple sample comparison of means The difference test
(LSD) was applied to establish statistical differences. All statistical analyses were
performed with Desing Expert Plus 8.0 software and differences were considered
significant at p < 0.05.
The incorporations of increasing percentages of amaranth flour in the dough
formulations progressively and significantly increased protein, lipid and ash content with
respect to the control sample, as well as variation is also found with increasing brown
rice flour (Table 1). The highest percentages of nutrients were recorded when wheat
flour was substituted by precooked amaranth flour. These results are in agreement with
other studies on breads in which a different species of amaranth is incorporated. (Sanz-
Penella, Tamayo-Ramos, Sanz, & Haros, 2013)These authors found a higher moisture
content when they increased the wheat flour substitution. This coincides with the
research where only the substitution with A. hypochondriacus at 25% and 50% was
performed, showed a significant difference in this parameter with respect to the bread
control, other studies show that despite the higher water absorption of the flour
mixtures measured by the farinograph, from 55.0% for wheat flour to 57.5%-60.5% for
wheat/amaranth combinations, with a higher water holding capacity of the doughs when
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e-ISSN: 2576-0971
the amaranth integral flour in the formulation was increased, in general, amaranth did
not significantly modify the moisture of fresh bread. (Penella, Collar, & Haros, 2008),
(Miranda, Sanz-Ponce, & Haros, 2019).
Table 1. Composition of raw materials and blends.
12,2 (0,2)
2,3 (0,02)
9,13 (0,02)
1,6 (0,01)
12,9 (0,05)
1,9 (0,02)
11,54 (0,03)
2,3 (0,03)
11,58 (0,02)
3,4 (0,2)
1,8 (0,02)
12,78 (0,02)