Nigerian Journal of Fisheries Vol. 12 (1) 2015
©Fisheries Society of Nigeria 801
NUTRITIVE PROPERTIES AND CONSUMER ACCEPTANCE OF SOLAR TENT AND
SUN DRIED KILISHI FROM BONY-TONGUE (Heterotis niloticus, Cuvier 1829) IN A
SEMI-ARID ZONE OF NIGERIA
*BELLO, M.M. & Y.D. TEKWATA
Department of Fisheries, University of Maiduguri, Maiduguri, Borno State, Nigeria
*Correspondence: mmbello2002@yahoo.com, +234 8035663565
ABSTRACT
This study was carried out to determine the nutritional characteristics of solar tent and sun dried kilishi of bony
tongue fish (Heterotis niloticus). Thirty freshly caught samples of Heterotis niloticus from Lake Alau in Maiduguri,
Nigeria with an average weight of (239.6 ± 44.9 g) were used for the study. The kilishi from the species was
prepared using two different slurry formation of high (50%) and low (24.35%) proportion of groundnut dough and
spices mixture respectively. The kilishi was dried in solar tent and open sun-drying in three replicates. The
proximate composition was determined for moisture, protein, ash, crude fibre, and crude fat, in percentages. The
prepared kilishi products were subjected to statistical analysis using two- way analysis of variance (ANOVA). The
result of proximate composition indicated that the solar-dried kilishi recorded significantly higher (P > 0.05)
protein content 63.03 ± 1.64, higher ash content 5.33 ± 0.81 and crude fibre (19.00 ± 0.81) while the sun dried
kilishi recorded higher moisture content 7.60 ± 0.81 in sun dried product despite lower values in fibre 6.00 ± 0.08,
fat 2.00 ± 0.40 and crude protein 50.76 ± 0.02. Sensory scores of solar-dried rated significantly higher values for
taste, colour, flavour, appearance and general acceptability with mean scores of 5.20 ± 0.90, 6.00 ± 0.90, 5.90 ±
0.16, 6.20 ± 0.16, and 5.90 ± 0.63 respectively, while the sun dried kilishi recorded lower sensory parameters 4.30 ±
0.89, 5.10 ± 0.81, 4.90 ± 0.16, 3.40 ± 0.08, and 5.10 ± 0.81 respectively for the above parameters. It can be
concluded that kilishi prepared from solar tent was the most acceptable by the taste panel while the sun dried kilishi
was least accepted. However, fish kilishi from solar-dried tent form a product attractive to consumers and increased
shelf-life, hence explored alternative preservation techniques to reduce fish spoilage and post-harvest losses.
Keywords: kilishi, Heterotis niloticus, sun, solar tent, drying.
INTRODUCTION
Fish is an extremely perishable food with
deterioration commencing immediately after harvest
(Agbo et al., 2002). Prior to death, the enzymes
normally get involved in the digestion of ingested
food and all microbial activities are controlled. As
soon as fish dies, enzymatic action begins on the
flesh and alimentary system leading to soft
destructive changes. The process is referred to as
autolysis. Post-harvest losses could be minimized by
the application of proper preservation and processing
methods (Eyo, 1997). Sun-drying is one of the oldest
known fish preservation methods. It involves the
subjection of fish to heat from the sun by spreading it
on a flat surface that is exposed to sunlight. This
enables moisture loss to be achieved and so, results in
the drying of the fish. The characteristic low moisture
content of dried fish makes them to be shelf stable at
low water activities (Ligia, 2002). Solar energy has
been used for centuries by man for drying animal
flesh, skins, preserving meat, fish and agricultural
crops (Akinola et al., 2006). Solar dryers have been
developed worldwide as a means of generating solar
energy for drying varieties of agricultural product
(FAO, 1992). Therefore, solar dryers introduction to
developing countries will reduce post-harvest fish
losses, produce better quality products compared to
sun or shade drying which are traditional (Yaldiz et
al., 2001). Fish drying is an age long practice across
the world. It is one of the methods of fish
preservation and value addition which can improve
the quality.
Processing methods include raising the
temperature by canning, boiling, removal of moisture
by natural drying, mechanical drying, smoking,
salting and fish product development such as kilishi
(Magawata and Oyelese, 1999).
Spices can be defined as natural vegetable
products that are used to add seasoning and impart
aroma to food (ISO, 1972). Spices like other food
substances, may carry some bacteria, yeast, molds,
spores and even some insects. The use of natural
spices in meat and fish processing to curtail rancidity
is recommended and these include the use of green
onion, green pepper seeds and tomato peel on roasted
beef (ICMSF, 1986). Kilishi is Hausa word which
refers to slicing, dressing, sun-drying, application of
slurry of spices and roasting on a glowing fire,
processed goat, sheep or beef. Kilishi production is
traditionally practiced in the northern parts of