Bioscience Methods 2017, Vol.8, No.2, 18-30
29
Eight species of fungi,
Mucor plumbeus, Rhizopus
stolonifer, Alternaria tenuissima, Aspergillus
niger, Fusarium
solani, Penicillium
chrisogenum, Trichoderma
longibrachiatum and
Yeast
Candida sake
were isolated from
freshly produced snack while thirteen species of fungi,
Mucor plumbeus, Rhizopus
stolonifer, Alternaria
tenuissima, Aspergillus
niger, Fusarium solani, Penicillium
chrisogenum, Trichoderma
longibrachiatum,
Yeast,
Aspergillus
fumigatus, Fusarium
verticilliodes, Mucor
hiemalis,
and
Aspergillus
flavus,
were isolated from
packaged snacks. The trend in microbial load of packaged snacks indicated that the lower the pH values the higher
the microbial counts. Snacks packaged in aluminum foil had the highest microbial load and least pH values in all
the treatments while Polythene had the least microbial load and fluctuating pH values, this is similar to Ogunsola
and Omojola (2008) observation for beef and pork kilishi. The higher microbial load in aluminum foil might be,
due to absence of pore in the material, and resultant buildup of moist, warm, a favourable environment for the
spore producing microbes to sporulate under ambient condition.
Staphylococcus aureus
is normal skin flora of
25% healthy human and it does not cause diseases unless mixed with foods.
Staphylococcus aureus
is significant
among
staphylococcus
genus as it can produce different types of toxins which are heat resistant.
Staphlococcus
aureus
was the most prominent spoilage organism isolated; they survived in all the samples analyzed. Pearson
(1986) reported
Staphlococcus aureus
as a Gram positive bacterium, its toxin causes food poisoning and it is
resistant to heat,
radiation and drying. Evans et al. (1983) reported
S. aureus
as a major cause of food poisoning
and as a facultative
anaerobe can grow under both aerobic and anaerobic
conditions. Although it was dominant in
all samples, however, its level was still within the range of satisfactory microbial load for human health (ICMSF,
2002).
Pseudomonas
spp are known to be spoilage bacteria, especially
P. aeruginosa
and
P. fluorescens
have been
considered as opportunistic pathogenic species (Altinok et al., 2006). The presence of
P. aeruginosa
could be
attributed to its being part of normal floral of fresh water fishes and its inherent spores which sporulate in
favourable condition.
Table
8 Microorganisms isolated from different snack samples
Snack sample
Microorganisms isolated
sample a
micrococcus
spp
., aspergillus
spp
., fusarium verticiliodes, staphylococcus aureus, mucor
spp
., fusarium
spp
.,
penicilium
spp
. ,alternaria
spp
., pseudomonas aeruginosa, rhizopus stolonifer trichoderma longibrachiatum,
candida sake and
yeast
sample b
bacillus
spp.,
staphylococcus aureus, micrococcus
spp.,
aspergillus
spp.
sample c
bacillus
spp.,
staphylococcus aureus
,
aspergillus
spp and
fusarium
spp.
sample d
micrococcus
spp.,
aspergillus
spp.,
fusarium verticiliodes, staphylococcus aureus
Note: A =Untreated; B = Ocimum gratissimum fortified snack; C = Vernonia amygdalina fortified snack; D = Mixture of Vernonia
amygdalina plus Ocimum gratissimum fortified snack
Mould thrives better in medium with high moisture content (Pearson, 1986). The presence of
Aspergillus
spp
and
Mucor
spp which are spoilage fungi
could be as a result of moist environment created by Aluminum foil
packaging material which favoured their growth and consequent high population in the sample.
Physical observation of snacks after the period of ten days storage in the different packaging materials revealed
that Polythene was the best packaging material for the snacks as no change was observed in snacks packaged in
polythene. Snacks packaged in aluminum foil had varying degrees of colour change due to presence of mould, this
could be due to absence of pore in aluminum foil which might have allowed heat and moisture to buildup thus
creating favourable environment for mould growth.
In this study, polythene was the best packaging material in terms of physical and microbial qualities, snacks were
microbiologically safe for consumption within ten days of production the microbial load were below the limit (10
3
cfu/g) recommended by ICMSF in Good Manufacturing Practice (GMP).
Acknowledgements
My gratitude goes to my Maker, best friend, Comforter, hope, saviour, guider, Jesus Christ for the grace bestowed on me to complete
