International Journal of Nutritional Science and Food Technology
An Open Access Journal
Volume 3 Issue 1, January 2017
H.E. Dienye et al , IJNF 2017, 3:1
International Journal of Nutritional Science
and Food Technology
Vernonia amygdalina (BITTER LEAF) EXTRACTS AS PRESERVATIVE FOR
CATFISH (Clarias gariepinus)
Research Article Open Access
*Corresponding Author: H.E. Dienye, Department of Fisheries Technology, FCFFT, New Bussa. Niger State, E-mail: henrydienye@
gmail.com
Citation: H.E. Dienye, R.N. Oladosu-Ajayi, C.T. Ajayi and I.U. Agha (2016). Vernonia amygdalina (BITTER LEAF) EXTRACTS
AS PRESERVATIVE FOR CATFISH (Clarias gariepinus) Int J Nutr Sci & Food Tech 3:1, 102-108
Copyright: © 2017 H.E. Dienye et al. This is an open-access article distributed under the terms of the Creative Commons
Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original
author and source are credited.
ISSN 2471-7371
Received January 4, 2016; Accepted January 22, 2016; Published January 30, 2016.
Introduction
Fish is a highly perishable commodity which spoils immediately
after capture. The rate at which bacteria grow in fish is significantly
reduced at low temperature. One of the simplest ways of lowering
fish temperature thereby retarding bacteria growth is to ice
the fish. As soon as the fish is iced, heat is transferred from the
fish to the ice causing the ice to melt. This continues until an
equilibrium temperature is reduced between the ice and the fish.
This temperature will be a little above O
0
C if sufficient quantity of
ice is used. At this temperature, the activities of micro organisms
are reduced and the storage life of fish is prolonged. As the ice
melts, the flowing water washes away bacteria and other debris
from the fish. There have been many research studies regarding
the shelf-life of fish stored in ice. Based on these studies, it is
generally accepted that some tropical fish species can keep for
longer periods in comparison to fish from temperate or colder
water (Clucas, 1985). This can be attributed to differences in the
bacteria growth rates in tropical fish stored in ice. However due to
differences in the criteria used to define the limit of shelf-life, and
methodologies used, comparison between shelf-life of fish from
tropical and temperature waters is still difficult (Clucas, 1985).
The herb known as the bitter leaf is a shrub or small tree that can
reach twenty three feet in height when fully grown. Bitter leaf has
a grey or brown coloured bark; the bark has a rough texture and
is flaked. (Butter and Bailey, 1973)The leaves are used for human
consumption and washed before eating to get rid of the bitter taste.
They are used as vegetable and stimulate the digestive system, as
well as they reduce fever. Furthermore, Vernonia amygdalina is also
used instead of hops to make beer in Nigeria (Butter and Bailey,
1973). It has been observed to be eaten by goats in central zone of
Delta state, Nigeria. However, in general has there been found, that
Vernonia amygdalina have an astringent taste, which affects its
intake (Bensi et al; 1995). The bitter taste is due to anti-nutritional
factors such as alkaloids, saponins, tannins and glycosides (Butter
and Bailey, 1973). This work is therefore undertaken to preserve
and extend the shelf-life of freshly slaughtered catfish (Clarias
gariepinus) using extracts of bitter leaf also determine which
1
R.N. Oladosu-Ajayi,
2
H.E. Dienye,
1
C.T. Ajayi and
1
I.U. Agha
Keywords: Vernonia amygdalina (Bitter leaf), Preservative, Extract, Catfish
Abstract
Ethanol, hot water and cold water extracts of bitter leaf (Vernonia amygdalina) were used as a preservative for catfish (Clarias gariepinus)
to determine how far it can extend its shelf life. It was observed that the Ethanolic extract of bitter leaf was able to extend the shelf life
of catfish (Clarias gariepinus) from the 24 hours as seen in the unpreserved sample to 36 hours post-slaughter after which it become unfit
for consumption. The hot and cold water extracts could only preserved the fish for 20 hours post-slaughter. These two extract cannot
thus be used to preserved catfish (Clarias gariepinus) as it could not even keep the fish fit for consumption for as long as it would have
when unpreserved. Ethanol proved the best solvent of extracting bitter leaf because of its ability to liberate its phytochemical compounds
unlike the hot and cold water extracts. This observation thus makes ethanolic extract of bitter leaf (Vernonia amygdalina) a useful natural
fish preservative.
1
Department of Fisheries Technology, FCFFT, New Bussa. Niger State
2
Department of Fisheries. University of Portharcourt, Rivers State
102