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ASIAN JOURNAL OF
SCIENCE AND TECHNOLOGY
ISSN: 0976-3376
Asian Journal of Science and Technology
Vol. 4, Issue 11, pp.199-202, November, 2013
RESEARCH ARTICLE
THE NUTRIENT CONTENTS OF TRADITIONAL SUN- DRIED NILE FISH IN SUDAN
*Elagba H. A. Mohamed
Natural History Museum, Faculty of Science, University of Khartoum, P.O. Box 321, Khartoum, Sudan
ARTICLE INFO
ABSTRACT
Article History:
The chemical compositions gross energy and mineral contents were determined for sun dried fish: Lates
niloticus, Tetraodon lineatus, Heterotis niloticus, Mormyrus niloticus, Clarias lazera and Protopterus
annectens. Protein value of over 70g/100g was recorded for the analyzed fish except C. lazera which
contained (59.9±1.4g/100g). The range of lipid content was (2±0.1-16.6±0.8g/100g), with the highest
values in C. lazera and M. niloticus. The range of ash was (3.9±0.1-13.6±0.9g/100g), high in
P. annectens and C. lazera than in remaining species. Energy value was (475-555 Kcal/100g) high in
C. lazera. Minerals were dominated by Ca, Na, K and P which form 99% of total minerals. The value of
Mg was (1.4-2mg/100g) and the values of other minerals were <1mg/100g. The results revealed that
sun-dried product (Kajaike) of Nile fish is a good source of proteins, minerals as well as energy, thus
has high nutritional value for healthy diet. The data may benefit the fishery industry, nutritionists and
researchers to improve the nutritive value, processing techniques and marketing of selected fish.
Received 15th August, 2013
Received in revised form
27th September, 2013
Accepted 23rd October, 2013
Published online 19th November, 2013
Key words:
Ash,
Energy,
Fatty acids,
Lipids,
Minerals,
Nile fishes,
Proteins,
Sun - drying.
Copyright © 2013 Elagba H. A. Mohamed. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted
use, distribution, and reproduction in any medium, provided the original work is properly cited.
INTRODUCTION
Fish is an extremely perishable food item and required
preservation for future uses. Several methods are followed
over the world for preserving fish to extend its shelf-life,
including drying, salting and smoking (Reza et al., 2007;
Abolagba and Melle, 2008). Fish in any of these forms give
rise to products of great economic importance and the demand
for such products has been increasing. Dry fish is a very
favorite food item and used as a substitute of fish at the
scarcity of fresh fish in many countries (Bille and Shemkai,
2006; Oyero et al., 2007; Chukwu and Shaba, 2009; OduorOdote et al., 2010). There have been some reports on the
composition of dry product of fish in some countries (Ako and
Salihu, 2004; Oyero et al., 2007; Abolagba and Melle, 2008;
Patterson and Ranjitha, 2009; Reza et al., 2009). The
nutritional quality of traditional dried products of freshwater
small indigenous species of Bangladesh was evaluated by
Nurullah et al. (2002) and Siddique et al. (2012). The
influence of traditional fish processing on the nutritional and
microbiological qualities was also investigated (Khan and
Khan, 2002; Chavan et al., 2008; Chukwu, 2009; Ahmed et
al., 2011; Koffi-Nevry et al., 2011). The Nile fish constitute a
very important component of the diet and often provides the
much needed nutrient for Sudanese people (Mohamed et al.,
*Corresponding author: Elagba H. A. Mohamed
Natural History Museum, Faculty of Science, University of
Khartoum, P.O. Box 321, Khartoum, Sudan
2010). Fish is however susceptible to damage as soon as it
harvested, due to the high temperatures in Sudan and the lack
of storing and distributing facilities of fresh fish. Sun-drying
is one of the traditional methods employed to preserve fish in
Sudan. Sun drying is a low cost method and the product plays
an important role particularly in providing nutrition to the poor
and economically disadvantaged people, especially in remote
areas with few rainfall and seasonal water streams. The
process of sun-drying a fish consists of simply laying whole
fillets or strips of fillets on drying racks directly under the sun,
in the open air using solar energy to evaporate the water
content in the fish, and the dry product is known as “kajaike”.
However, little is known about the nutritional quality of the
dried Nile fish products.
Better knowledge of their nutritional value, which is expected
to be closely associated with fish species, could contribute to
the understanding of variability in meat quality of different
species of the Nile fish. Moreover, the measurement of some
proximate profiles such as proteins, lipids, energy, ash and
mineral contents is often necessary to ensure that they meet
the requirements of food regulations and commercial
specifications (Waterman, 2000). In view of these facts, the
present study was therefore initiated to assess the nutritional
quality of the most popular sun-dried species of the Nile fishes
namely Lates niloticus, Tetraodon lineatus, Heterotis
niloticus, Mormyrus niloticus, Clarias lazera and Protopterus
annectens in Sudan. The purpose of this study is to determine
the proximate compositions, energy and minerals contents, and
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Asian Journal of Science and Technology Vol. 4, Issue 11, pp.199-202, November, 2013
to inform the consumer about the nutrient content of the dry
product of fish (Kajaike) and to guarantee its optimal use as a
good source of healthy food and energy.
MATERIALS AND METHODS
Fish collection and sampling
Sun-dried strips of fish fillet of Lates niloticus, Tetraodon
lineatus, Heterotis niloticus, Mormyrus niloticus, Clarias
lazera and Protopterus annectens were purchased from the
central fish market in Khartoum, crushed and grinded.
Samples of powder of each species were weighed and freeze
dried by Freeze Dryer model 230 to - 40°C and the
surrounding pressure was reduced to 110, using
(MODULYOD) to remove water from the powder, until the
samples had constant weights.
Chemical analysis
The proximate constituents of the dry samples were
determined by the method of the Association of Official
Analytical Chemists (AOAC, 2005). The gross energy of the
samples was determined against thermocouple grade benzoic
acid using a Gallenkamp ballistic bomb calorimeter (Model
CBB-330-0104L). The minerals were analyzed from solutions
obtained by first dry ashing the sample at 550 0C and
determined after wet digestion with a mixture of nitric,
sulphuric and hydrochloric acid using Atomic Absorption
Spectrophotometer (AAS Model SP9). Each analysis was
carried out in triplicates. The results are provided as (mean ±
standard deviation).
RESULTS AND DISCUSSION
The results of proximate compositions and gross energy values
of the sun-dried product of L. niloticus, T. lineatus, H.
niloticus, M. niloticus, C. lazera and P. annectens are given in
Table 1 and Figure 1.
The crude protein value of over 70 g/100 g was recorded for
all the analyzed fish except C. lazera contain (59.9 ± 1.4 g/
100g). The low value in protein concentration of this fish
might be a result of storage period of the product. This agree
with the findings of Abolagba and Osifo (2004) and Abolagba
and Melle (2008) who worked on the fatty fish Clarias
gariepinus and reported that protein decomposes with passing
time. The value of crude protein in dry product of C. lazera
was comparable with that of dry C. gariepinus (Chukwu and
Shaba, 2009). The protein level in the analyzed fish is also
comparable with the studies of Ahmed et al. (2011) in sundried and smoke-dried Tilapia nilotica and Silurus glanis
(51.68±2.62-75.72±3.66 g/100 g) from Lagdo lake in
Cameroon, Siddique et al. (2012) in three marine dry fish
(52.44 -71.32%). The value of crude lipid ranged between
(2.03 ± 0.04 g/100 g) and (16.55 ± 0.38 g/100 g) with the
highest value recorded for the dry products of C. lazera and M.
niloticus than the rest four species.
The value of crude lipid was lower in dry product of L.
niloticus, and higher in T. lineatus compared with the values
recorded in the fresh tissues of the same species (Mohamed et
al., 2010). Nurullah et al. (2002) found high protein and low
lipid content in traditional dried products of freshwater fish
species in Bangladesh. Ahmed et al. (2011) recorded 0.59 3.31 g/100 of lipid in sun-dried freshwater fish from Lagdo
Lake in Cameron. On the other hand, Chukwu and Shaba
(2009) recorded high value of crude lipid in dry C. gariepinus.
The different values observed in the results of different studies
could be related to types of diet, age, sex and habitat of fish.
However, the sun-dried product of the species studied fall into
the classification of high protein and low lipid contents. Ash
contents in the analyzed dried samples varied significantly
among studied dry fish species (P < 0.001). The range was (3.9
± 0.1 - 13.6 ± 0.9 g/100 g), high in P. annectens than in the
remaining fish species. Total ash contents obtained in this
study for the other five fish species were close to those
Table 1. Proximate compositions (g/100g) and gross energy (Kcal/100g) of the product of six commercial sun- dried Nile
fish in Sudan
Parameters
Protein
Lipid
Ash
Energy value
L. Niloticus
74.2±.9
2±0.1
4.4±0.4
475
T. lineatus
71.5±1.3
4.9±0.3
3.9±0.1
510
H. niloticus
78.8±0.6
12.5±0.3
5.2±0.2
498
Figure 1. Mineral Composition (mg/100g dry weight) in the
product of six commercial sun-dried species of the Nile fish in
Sudan
M. niloticus
73.4±1.4
3.8±0.1
5.9±0.1
510
C. niloticus
59.9±1.4
16.6±0.8
9±0.6
555
P. annectens
68±0.6
4.5±0.9
13.6±0.9
475
determined by and Ahmed et al. (2011) in some dried
freshwater fish and Siddique et al. (2012) in some marine
dried fish. The caloric value 555 Kcal/100g recorded for C.
lazera was higher than the other five fish species (475 – 510
Kcal/100g). The values were higher than those reported in
fresh Nile fish (Mohamed et al., 2010), but are comparable
with those of Chukwu (2009) and Jabeen and Chaudhry
(2011). However, the energy content was very high in all
analyzed dry fish showing them to be good sources of
concentrated energy. The high caloric values of the dry Nile
fish species are within the recommended values of 450 to 600
Kcal/100 g for human and so could contribute to caloric
requirement of consumers. The mean mineral contents were
dominated by calcium, sodium, potassium phosphorus and
iron while other minerals had values less than one mg/100 g
(Table 2). The content of Mg was low (2 mg/100g) in all fish
species, although it is a major element. This might be due to
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Asian Journal of Science and Technology Vol. 4, Issue 11, pp.199-202, November, 2013
Table 2. Mineral Composition (mg/100g dry weight) in the
product of six commercial sun-dried species of the Nile fish in
Sudan
well as scholars interested in fishery and aquaculture. Further
research should include essential fatty acids and amino acids
to investigate the nutritional value of the common dry Nile
fishes. Dry products of fish may be very susceptible to
oxidative deterioration and off-flavor development during
storage. Therefore, further research is needed to develop
methods to improve preservation techniques of the dry fish in
Sudan.
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fish (Ako and Salihu, 2004; Ahmed et al., 2011).
Figure 2. Proximate compositions (g/100g) and gross energy
(Kcal/100g) of the product of six commercial sun- dried Nile fish
in Sudan
Conclusion and Recommendations
The data showed that the dry product (Kajaike) of Nile fishes
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