Food and Nutrition Sciences, 2010, 1, 19-23
doi:10.4236/fns.2010.11004 Published Online July 2010 (http://www.SciRP.org/journal/fns)
19
Effect of Technological Treatments on Cassava
(Manihot Esculenta Crantz) Composition
Sahoré Drogba Alexis*, Nemlin Gnopo Jean
UFR des Sciences et Technologies des Aliments, Université d’Abobo-Adjamé, Abidjan, Côte d’Ivoire.
Received March 30th, 2010; revised June 26th, 2010; accepted July 8th, 2010.
ABSTRACT
The composition of cassa va roots and those of its derived food (attiéké and semolina), were determined. The compara-
tive study of the cassava roots composition with those of the semolina and attiéké has shown that the technological ap-
plied treatments in the preparation of cassava meal and attiéké influenced its composition. Thus, apart from the lipids
content and energy values which slightly increased, all the components (protein, ash, cellulose, carbohydrates, starch
and hydrocyanic acid ) decreased in food derived from cassava.
Keywords: Cassava, Semolina, Attiéké, Composition, Technological Treatment
1. Introduction
Cassava has been widespread in all tropical regions of
the globe, because of the ease of its culture [1]. However
on the nutritional point of view that plant is toxic in all
its parts [2]. Indeed the crude cassava roots contain some
cyanogenic glycosides. These glycosides are conv er ted in
prussic acid (hydrogen cyanide, HCN) when the cells of
cassava roots are ruptured. Good methods of preparation
and cooking reduce the levels of cyanide and acute poi-
soning occurs very rarely. Contrariwise, a chronic toxic-
ity due to cyanide appears in case of a high consumption
of cassava. Especially when the consumption of iodine
and/or proteins is very low [1].
Cassava roots are rich in energy and contain mainly
starch and soluble carbohydrates [3]. Although they are
low in protein, it is a staple food for about 200 to 300
million people worldwide [4]. Cassava is consumed in
various forms [5]. The aim of our work is to study the
roots composition of two varieties of cassava and to
show the influence of technology on the cassava food
value compared to two derived food, semolina and at-
tiéké.
2. Material and Methods
For this study we used as plant material two varieties of
cassava roots, a bitter variety “bouanga Koutouan” and a
sweet variety “Bonoua red” and also samples of foods
derived from cassava : Attiéké bought in Abidjan market
and semolina prepared from studied cassava roots.
3. Chemical Analysis
Water content determined by drying at 105°C with con-
stant weight [6], the protein content determined by the
method of Kjeldahl with 6.25 as conversion factor, the
lipid con tent determined by So xhlet extraction with ether,
and the ash content determined by incineration at 650°C
in muffle furnace [7]; the cellulose content determined
by the method of Weender [8], the carbohydrate content
determined by difference; the starch content calculated
by multiplying the carbohydrate content by the conver-
sion factor 0.9, the energy value calculated by equation
(4 × protein content) + (9.75 × lipid content) + (4.03 ×
glucids content) [9]; hydrocyanic acid (HCN) content
determined by alkaline titration [10].
4. Results
4.1 The Composition of Cassava Roots is Given
in Table 1
The indicated values represent the average of three de-
terminations. The water content varies from 48.02 ±
0.80% (bitter cassava) to 68.84 ± 1.50% (sweet cassav a).
The carbohydrate content varies from 94.62% ± 1.34 dm
(sweet cassava) to 94.70 ± 2.67% dm (cassava). The
starch is the dominant fraction of carbohydrates; it repre-
sents 85.16 ± 2.21 - 85.23 ± 2.42% of these carbohydrates.
The protein content varies from 1.80% ± 0.02 dm (bitter
cassava) to 1.84% ± 0.13 dm (sweet cassava). The lipid

Effect of Technological Treatments on Cassava (Manihot Esculenta Crantz) Composition 20
Table 1. Composition of cassava roots
Eléments
Cassava
roots
Water
% m f Protein % m.s Lipid % m.s Ash % m.sCellulose % m.s Carbohydrates % m.s Starch % m.sEnergy value (cal/100g m.s) HCN % m.s
sweet specie 68.84
± 1.50 1.84 ± 0.13 1.00 ± 0.09 2.53 ± 0.112.95 ± 0.33 94.62 ± 1.34 85.16 ± 2.21371.49 ± 37.59 0.1×10¯² ±0.00
bitter specie 48.02
± 0.80 1.80 ± 0.02 1.01 ± 0.02 2.49 ± 0.143.66 ± 0.01 94.70 ± 2.67 85.23 ± 2.42371.72 ± 20.22 0.13×10¯² ± 0.00
The indicated values represent the average of three determinations.
content varies from 1.00% ± 0.09 dm (sweet cassava) to
1.01 ± 0.02% dm (bitter cassava). The ash content varies
from 2.49% ± 0.14 dm (bitter cassava) to 2.53 ± 0.11%
dm (sweet cassava). The cellulose content varies from
2.95% ± 0.33 dm (sweet cassava) to 3.66 ± 0.01% dm
(bitter cassava).
The Hydrocyanic acid content varies from 0.001 ±
0.00% dm (sweet cassava) to 0.0013 ± 0.00% dm (bitter
cassava). The energy value varies from 371.49 ± 37.59 to
371.72 ± 20.22 cal/g 100 dm (bitter cassava).
The composition o f foods derived from cassava for in-
stance semolina and attiéké are respectively in Tables 2
and 3. The values in each table represent the average of
three determinations.
4.2 Composition of the Semolina (Table 2)
The carbohydrate content varies from 94.53 ± 1.79% dm
(sweet cassava) to 94.57 ± 2.14% dm (better cassava).
The protein content varies from 1.77% ± 0.02 dm (bitter
cassava) to 1, 79% ± 0.57 dm (sweet cassava). The lipid
content varies of1, 20% ± 0.01 dm (bitter cassava) to
1.22% ± 0.06 dm (sweet cassava). The ash content varies
from 2.46% ± 0.06 dm (bitter cassava) to 2.50% ± 0.28
ms (sweet cassava). The cellulose content varies from
2.52% ± 0.09 ms (sweet cassava) to 2.96% ± 0.41 dm
(bitter cassava). The energy value of the semolina varies
from 372, 88 ± 21.59 cal/100g dm) (bitter cassava) to
372.92 ± 8.41 cal / 100g dm (sweet cassava).
Hydrocyanic acid which is an anti-nutritional factor in
the semolina is in the residual state in the semolina, it
varies from 0.0001% dm (sweet cassava) to 0.0002% dm
(bitter cassava).
4.3 Composition of Attiéké (Table 3)
The carbohydrate content varies from 94.50% ± 1.41 dm
(sweet cassava) to 94.53% ± 1.41 dm (bitter cassava).
The protein content varies from 1.70 ± 0.00% dm (bitter
cassava) to 1.75 ± 0.01% dm (sweet cassava). The lipid
content varies from 1, 25% ± 0.03 dm (sweet cassava) to
1, 40% ± 0.05 dm (bitter cassava). The ash content varies
from 2.37% ± 0.01 dm (bitter cassava) to 2.49 ± 0.02%
dm (sweet cassava). The cellulose content varies from
0.91% ± 0.04 dm (sweet cassava) to 1.85 ± 0.07% dm
(bitter cassava). The energy value of attiéké is high,
varying from 373.00 ± 25.4 cal/100g dm (sweet cassava)
to 374.31 ± 28.1 5 cal/100g dm (bitter cassava).
Hydrocyanic acid which is an antinutritional factor in at-
tiéké is in the residual state, it corresponds to 0.0001% dm.
5. Discussion
The moisture content o f cassava roots is equal to average
58.43% pf, it is the same level of magnitude as the values
Table 2. Composition of cassava semolina
elements
Semoule Water
% ps Protein % m. s Lipid % m. s Ash % m. s Cellulose % m. s Carbohydrate % m. s Starch % m. s
Energy
value
(cal/100g m.s)
HCN
% m. s
sweet specie 13.50
± 1.40 1.79 ± 0.57 1.22 ± 0.06 2.50 ± 0.28 2.52 ± 0.09 94.53 ± 1.79 85.06 ± 1.46 372.92 ± 8.41 0.01×10¯² ± 0.00
bitter specie 13.20
± 0.30 1.77 ± 0.02 1.20 ± 0.01 2.46 ± 0.06 2.96 ± 0.41 94.57 ± 2.14 85.11 ± 0.30 372.88 ± 21.59 0.02×10¯² ± 0.00
The indicated values represent the average of three determinations.
Table 3. Composition of attiéké bought in the market
elements
Attiéké Water
% p f Protein % m. s Lipid % m.s Ash % m.sCellulose % m.s Carbohydrate % m.s Starch % m.s
Energy
value
(cal/100g m.s)
HCN
% m.s
sweet specie 55.21
± 0.06 1.75 ± 0.01 1.25 ± 0.03 2.49 ± 0.020.91 0.04 94.50 ± 1.41 84.65 ± 0.09373.00 ± 25.4 0.01×10¯² ± 0.00
bitter specie 48.00
± 0.10 1.70 ± 0.00 1.40 ± 0.05 2.37 ± 0.011.85 ± 0.07 94.53 ± 1.26 84.99 ±0.90 374.31 ± 28.15 0.01×10¯² ± 0.00
The indicated values represent the average of three determinations.

Effect of Technological Treatments on Cassava (Manihot Esculenta Crantz) Composition21
(54-58 pf) found by Favier [11]. The dry matter of cas-
sava roots is mainly composed of carbohydrates with 94.62
to 94.70% dm, its values are close to that (94.1% dm)
found by Woolfe [12].
These carbohydrates are composed mainly of starch,
about 85%. Bornet et al [13] found rates ranging from
approximately 84 to 87%.
The energy value of cassava roots is equal here aver-
age about 372 dm cal/100g. The high calorific value of
cassava starch is an energy food.
Cassava roots have a protein content equal to 1.81% dm
average; Favier [11] found a protein rate of the same
order of magnitude (2.0% dm).
The lipid content of cassava roots is average of 1.01%
dm. That percentage is close to the value of 0.99% dm
found by Abou a and Kamenan [14].
The ash content is average of 2.51% dm, this result is
consistent with the value of 2.50% dm found by Meuser
and Smolnik [15].
These different results indicate that cassava is a rich
food in carbohydrates but low in protein, lipid and min-
eral salts as indicated by Lingani et al [16].
The cellulose content is average equal to 3.31% dm.
This value is less than the minimum percentage of 5%
which would be tolerated in foods [17]. So cassava is a
digestible food.
The hydrocyanic acid content varies from 0.001 to
0.13 × 10¯²% dm, either an average grade of 0.11 ×
10¯²% dm. Hydrocyanic acid stays the main anti- nutri-
tional factor to be reduced or removed before eating cas-
sava.
The technological applied treatments to cassava roots
during the preparation of the semolina (Figure 1) and
attiéké (Figure 2) influence on its composition. The
variation differences of cassava composition elements
compared to the semolina and attiéké are respectively
shown in Tables 4 and 5.
Thus the protein content decreased in the semolina by
0.05% compared to sweet cassava and by 0.03% com-
pared to the bitter cassava. In attiéké, the protein content
decreased by 0.09% compared to sweet cassava and by
0.10% compared to bitter cassava. The decrease in the
protein content would be due in part to a loss of nitroge-
nous matter by solubilization during the roots cooking
[18].
The lipid content increased in semolina by 0.22%
compared to sweet cassava and by 0.19% compared to
bitter cassava. By cons in attiéké, the lipid content in-
creased by 0.25% compared to sweet cassava and by
0.39% compared to bitter cassava. Note that only the
lipid content increased in the semolina as in attiéké. Th is
could be explained by a condensation phenomenon of
lipids in the dry matter during the drying operation.
The ash content decreased in the semolina by 0.03%
Figure 1. Diagram of semolina preparation
Figure 2. Diagram of traditional preparation of attiéké
compared to sweet cassava and by 0.03% compared to
bitter cassava. In attiéké, the ash content decreased by
0.04% compared to sweet cassava and by 0.12% com-
pared to bitter cassava. The decrease in ash could be ex-
plained by the phenomenon of dissolution [19], the min-
eral elements pass in eliminated water during the process
of preparing food.
The cellulose content decreased by 0.43% compared to
sweet cassava and by 0.70% compared to bitter cassava.
There is a cellulose decrease in attiéké; its level has
dropped by 2.04% compared to sweet cassava and 1.81%
from bitter cassava.
The low rate of cellulose promotes digestibility of its
foodstuffs.
In semolina, carbohydrate content, decreased by 0.5 ×
10¯²% compared to sweet cassava and by 0.13% com-
pared to bitter cassava; in attiéké, carbohydrate content
decreased by 0.12% compared to sweet cassava and by
0.17% compared to the bitter cassava.
The hydrocyanic acid content in semolina decreased
by 0.09 × 10¯²% compared to sweet cassava and by

Effect of Technological Treatments on Cassava (Manihot Esculenta Crantz) Composition 22
Table 4. Differences between the compositions of the roots and semolina
Nutrients
Samples
Protein
% m. s Lipid % m.s Ash % m.sCellulose % m.s Carbohydrate % m.s Starch % m.s
Energy
Value
(cal/100g m.s)
HCN
% m.s
Sweet specie
roots/ semolina – 0.05 + 0.22 – 0.03– 0.43 – 0.05 – 0.10 + 1.43 – 0.09×10¯²
Bitter specie
roots/ semolina – 0.03 + 0.19 – 0.03– 0.70 – 0.13 – 0.12 + 1.16 – 0.11×10¯²
Table 5. Differences between the composition of the roots and attiéké
Nutrients
Samples Protein % m. s Lipid % m.s Ash % m.sCellulose % m.s Carbohydrate % m.s Starch % m.s
Energy
Value
(cal/100g m.s)
HCN
% m.s
Sweet specie
roots/ attiéké – 0.09 – 0.25 – 0.04– 2.04 – 0.12 – 0.51 – 0.51 – 0.09×10¯²
Bitter specie
roots/ attiéké – 0.10 – 0.39 – 0.12–1.81 – 0.17 –0.14 – 0.24 – 0.12×10¯²
0.11 × 10¯²% compared to bitter cassava. In attiéké the
hydrocyanic acid content decreased by 0.09 × 10¯²%
compared to sweet cassava and by 0.12 × 10¯²% com-
pared to bitter cassava.
The loss of this element would be linked in part to its
soluble and volatile nature at room temperature.
The technological applied treatments to cassava could
also explain the decrease in the content of some elements
of its composition compared to semolina and attiéké.
These derived foods are poorer in protein, lipid and min-
eral salt than the roots of cassava. The increase of lipids
rate in the semolina as in attiéké could explain the in-
crease in the energy value of semolina and attiéké. One
gram of burned lipid increases the energy value of 9.3
calories according to Atewater and Rosa [20].
6. Conclusions
The technological processing of cassava, in the prepara-
tion of their derived food such as semolina and attiéké,
has influenced its composition. Thus, the hydrocyanic
acid content, antinutritional factors characteristic of cas-
sava decreased in semolina and attiéké making their
consumption less hazardous. Regarding nutrients, except
the lipid rate and energy value that have increased in
semolina and attiéké, the rates of carbohydrate, protein,
mineral salt and cellulose decreased. Note however that
the main nutrient of cassava and its derived foods are
carbohydrates which are composed mainly of starch
whose high calorific value makes these commodities to
be energy foods. However, the poverty of those foods in
protein, lipid and mineral salt strongly lowers their nutri-
tional value.
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