Bioscience Methods 2017, Vol.8, No.2, 18-30
18
Research Article Open Access
Assessment of Microbiological and Keeping Quality of
Ocimum Gratissimum
and
Vernonia Amygdalina
Crude Extract on
Sarotherodon Galilaeus
Snacks
Tina Agbon Ileogben
1
, Olatunde Oginni
2
, Akele Olatunbosun
3
, Felix. A. Olajubu
2
, Mary Oluwaseun Omobuwa
2
, Blessing
Olusoji Ojo
2
, Eberechukwu Stella Umeh
2
, Ogunojemite Oladotun Ayodeji
2
1 Department of Animal and Environmental Biology, Adekunle Ajasin University, Akungba Akoko, Ondo State, Nigeria
2 Department of Fisheries and Aquaculture, Adekunle Ajasin University, Akungba Akoko, Ondo State, Nigeria
3 Department of Microbiology, Adekunle Ajasin University, Akungba Akoko, Ondo State, Nigeria
Corresponding author email
Bioscience Methods, 2017, Vol.8, No.2 doi
Received: 15 Sep., 2017
Accepted: 26 Oct., 2017
Published: 21 Nov., 2017
Copyright © 2017
Ileogben et al., This is an open access article published under the terms of the Creative Commons Attribution License, which permits
unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Preferred citation for this article:
Ileogben T.A., Oginni O., Olatunbosun A., Olajubu F.A., Omobuwa M.O., Ojo B.O., Umeh E.S., and Ayodeji O.O., 2017, Assessment of microbiological
and keeping quality of
Ocimum Gratissimum
and
Vernonia Amygdalina
crude extract on
Sarotherodon Galilaeus
snacks, Bioscience Methods, 8(2):18-30
(doi
Abstract
Evaluation of antimicrobial and keeping qualities potentials of
Ocimum
gratissimum
(OGE)
, Vernonia amygdalina
(VAE),
and
Ocimum
gratissimum
plus
Vernonia amygdalina
(OVE) crude extracts on fish snack made from
Sarotherodon galilaeus,
was
carried out to determine their for suitability for food preservation. Twelve fish samples grouped into three class sizes (A, B, C) were
used. They were gutted, filleted, cut into pieces, staked on palm frond sticks, and fortified with extracts, spiced and dried with a
smoldering fire. The snacks were allowed to cool and kept in Aluminum foil, Brown paper and polythene sheet. Snacks analysis for
microbial and keeping qualities was carried out using NA agar for bacteria and PDA for fungi using standard methods. Data collected
were subjected to ANOVA using SAS
®
2008 version 9.1. Mean pH value ranged from 9.60 ±0.1 to 11.10 ±0.15 for freshly produced
snack, untreated snacks had the least mean pH value (9.60 ±0.1) and the highest mean bacteria count (9x10
2
±2.65). Fungi counts
(5x10
2
±2.08
to 8x10
2
±6.08) were not significantly different between the samples. It was observed that snacks treated with
Ocimum
gratissimum
crude extract had the highest pH value and the lowest bacteria and fungi load; hence it was more effective for fresh
snack preservation. Five bacteria and eight fungi were isolated and identified. Result of pH and microbial analysis after storage
showed that the pH values ranged from 9.50 ±0.00 to 10.17 ±0.06. For treated snacks, snacks packaged in aluminum foil had the
least pH value and the highest microbial load, snacks packaged in brown paper had the highest pH value and the highest microbial
load. For packaged snacks, snacks treated with the mixture of
Ocimum gratissimum
and
Vernonia amygdalina
cude extraxts was
more effective as it had the lowest bacteria and fungi load. Microbiological analysis revealed that
Staphylococcus
aureus
and
Aspergillus spp
were the dominant bacteria and fungi isolated; however, their counts were within the acceptable limit of International
Commission on Microbiological Specification. Polyethylene bag gave the best result for packaging materials as it showed no
deleterious quality change in the snacks. Addition of plants extract and composite spice to the fish fillet had effect on the microbial
and shelf life of the product.
Keywords
Fish snack; Microbiological analysis;
Ocimum
gratissimum
;
Sarotherodon galilaeus
;
Vernonia amygdalina
λ
Background
Despite the high degree of awareness of food preservation methods, there is increasing occurrence of food loss/
disease outbreaks caused by spoilage and pathogenic microorganisms in foods. Due to consumer awareness and
negative perception of artificial preservatives in food, in recent years attention is shifting toward alternatives that
the consumers recognize as natural. In recent years, consumers prefer fewer chemicals and more natural foods,
thus, there is growing interest in using natural antimicrobial compounds, including extracts of herbs and spices, as
salt replacers or alternatives to synthetic compounds for food preservation (Witkowska, 2013). Plant extracts are
now getting more space in food industry to prevent the propagation of bacteria that affect the spoilage of food or
the spread of so-called food-borne diseases. The conditions of storage can also cause physiological spoilage.
Various methods exist to ensure that food maintain their quality long after harvesting (Oladotun and Deborah,
2013). The major shortcoming posed by the use of many antimicrobials is the chemical residues it deposits in the
food. The use of plants in preservation has been in use for a long period, though little understood then, it served its
