ABSRACT
The oil bean samples was gotten from
3 different locations within Umuahia.The comparative study of microbial profile
and physicochemical of raw and processed oil bean seed (Pentaclethra
macrophylla bentham) was carried out . A total of 6 bacterial species were
isolated which include Staphylococcusspecies, Bacillus,Proteus,
Lactobacillus species,
E. Coli, Micrococcuswith a percentage occurrence of 24%,
24 %,12%,16%,12% and 12% respectively. The pour plate method was
employed.Colonial morphology, gram staining and biochemical test were used for
bacteria identification.The
microbial load of the processed oil bean
seed ranges from 1.6x10 to 1.28x10-3 while the microbial load of raw oil bean
seed ranged from 3.9x10-4 to 2.8x10-4. The ph value of raw oil bean seed is
relatively neutral ranging from 6.8 to 7.0 while the processed oil bean seed
ranges from 5.1 to 6.9cm,the mean of the processed oil bean seed ranges from
2.8cm to 3.36cm and the colour of the unprocessed oil bean seed is dark brown
with a titratable acidity ranged from 0.17 to 0.21.The temperature of processed
ranges 31c to 32c and light brown in colour. Proximate analysis result of
unprocessed oil bean seed shows that the protein contents ranges from 17.27 to
19.19, the protein for the processed, ranges from 18.61 to 22.52, Fat of the
raw oil bean seed ranges from 22.92 to 25.21, while the fat of the processed oil
bean seed ranges from 15.14 to 16.24,the crude fiber of the unprocessed oil
bean seed ranges from 3.17 to 4.61 while the crude fiber of processed oil bean
seed ranges from 3.17 to 3.70,the ash content of the unprocessed oil bean seed
ranges from 2.48 to 3.16 while the processed oil bean seed ranges from 2.66 to
3.21, the moisture content of unprocessed oil bean seed ranges from 11.20 to 12.13
while the processed ranges from 33.10 to 33.90 and the carbohydrates content of
unprocessed oil bean seed ranges from 38.35 to 39.56 and the processed oil bean
seed ranges from 16.23 to 22.32. In conclusion , the study shows that both
unprocessed and processed oil bean seed provide a favourable condition for the
growth of Microorganism.
TABLE OF CONTENT
Title
page i
Certification ii
Dedication iii
Acknowledgement iv
Abstract v
Table
of contents vi
List
of table x
CHAPTER ONE
1.1
Background of the Study 1
1.2
Preparation of Ugba 2
1.3
Microorganism involved in fermentation 3
1.4
Microbiological safety of Ugba 4
1.5
Specific objectives 5
CHAPTER TWO
Literature Review 6
2.1.0
Description of fermented African oil bean seeds (Pentaclethra macrophylla
benth) 6
2.1.1
Nature of the plant and the seeds 7
2.1.2
Chemical composition of the seeds 7
2.1.3
Preparation of ugba 9
2.1.4
Microorganisms involved in the fermentation 11
2.1.5
Changes that occur during fermentation 13
2.1.6
Optimization of ugba fermentation 15
2.1.7
Nutritional value of Ugba 17
2.1.8
Toxicology of Ugba 20
2.1.9
Flavour components of Ugba 22
2.1.10
Packaging of Ugba 22
2.1.11
Microbiological safety of Ugba 23
2.2.0
In-vitro/Laboratory production of Ugba 24
2.2.1
Isolation of microorganism 25
2.2.2
Determination of some products of oligosaccharide hydrolysis in oil beanseed 26
CHAPTER THREE
3.1.0
Collection of samples 27
3.1.1
Preparation of culture media 27
3.1.2
Inoculation of microorganisms 28
3.1.3
Characterization and identification of microorganism from both raw and
processed Ugba 29
3.1.4
Gram staining 29
3.1.5
Biochemical test 30
3.1.6
Determination of physical properties of raw Ugba 31
3.1.7
Determination of physical properties of processed Ugba 31
3.1.8
Determination of chemical properties of raw Ugba 33
3.1.9
Determination of chemical properties of processed ugba 33
3.1.10 Ash Content And Determination Both Processed
And Unprocessed 35
3.1.11 Fat Cotent Determination Both Processed And
Unprocessed
35
3.1.12 Crude Fibre Determination Both Processed And
Unprocessed 37
3.1.13 Crude
Protein Determination Both Processed And Unprocessed 38
3.1.14
Determination Of Minerals Both Processed And Unprocessed 39
3.1.15
Determination Of Potassium And Sodium Both Processed And Unprocessed 33
CHAPTER FOUR
4.1 Cultural, Morphological And Biochemical Characteristic And
Identities Of Isolated Microorganisms 43
4.2 Microbial
(Bacteria) Load 0f Unprocessed And Processed Oil Bean Seed Samples 45
4.3 Percentage Occurrence Of Bacteria Isolates From Processed And
Unprocessed
Oil Bean Seed Samples 46
4.4
Occurrence Of Bacteria Isolates In Raw And Processed Oil
Bean Seed From
Different Umuahia Markets 47
4.5 Proximate
Composition Of Raw And Processed Oil Bean Seed From Umuahia
Markets. 49
4.6
Physicochemical Characteristic Of Raw And Processed
Oil Bean Seed 50
CHAPTER FIVE
5.0 DISCUSSION
AND CONCLUSION 51
Conclusion 53
Recommendation 53
Reference 54
Appendices
55
LIST OF
TABLES
Table 2.1 Fatty acid composition of African oil
bean seeds 6
Table 2.2 Amino
Acid Content (g/100 g protein of oil bean seed 8
Table 2.3 Succession of the major microorganisms
encountered in
fermentation of sliced oil
bean seeds (per gram) 9
Table2.4:Effect of different starter cultures on
ugba fermentation variables 14
Table2.5Mineral and vitamin content of unfermented
and fermented ugbad 16
Table2.6 Weight gain, feed intake, PER feed efficiency ratio and
digestibility of test sample fed to the rats
for 28 days*f 17
Table 4.1 Cultural, Morphological And Biochemical
Characteristic And
Identities
Of Isolated Microorganisms 36
Table 4.2
Microbial (Bacteria) Load Of Unprocessed And Processed
Oil Bean Seed Samples. 37
Table
4.3 Percentage Occurrence Of Bacteria Isolates From
Processed And Unprocessed Oil Bean
Seed Samples 38
TABLE 4.4: Occurrence Of Bacteria
Isolates In Raw And Processed Oil Bean
Seed
From Different Umuahia Markets 39.
TABLE 4.5:
Proximate Composition of Raw and Processed Oil Bean
Seed
from Umuahia Markets. 40
Table 4.6: Physicochemical Characteristic of Raw and
Processed Oil Bean Seed 41
CHAPTER ONE
1.1 BACKGROUND OF
STUDY
INTRODUCTION
Ugba is the
Igbo name for the fermented African oil bean seeds (Pentaclethra Macrophylla,
Benth). It is called Ukana by the Efiks in southern Nigeria. It is consumed by
an estimated 15 million people in Eastern Nigeria, Majority of who are igbos
(Odunfa and Oyeyiola, 1985). It is a traditional food general prepared in homes
as a small family business.
The method of production varies from
one producer to another, resulting in a non-uniform product (Nkoku and Okemadu,
1989). The beans that have been fermented for more than three days are taken as
a delicacy. Well fermented beans are added to soup as flavouring (Odunfa and Oyeyiola,
1985). It is widely consumed in eastern states of Nigeria with tapioca,
stockfish and garden eggs and leaves. It can also be eastern with bitter kola
(Garcinia kola) or kola nuts (cola acuminate and colanitida) and when prepared
with garden egg leaves are used to eat yam and cocoyam (Okafor et al, 1991,
Mbajuwa et al, 1998).
It is an important and cheap source
of protein for people whose staple foods are deficient in protein (Obeta, 1983).
The quantity of ugba produced annually is not known, since the seeds are
collected by individuals and sold in the market to ugba producers.
1.2 PREPARATION
OF UGBA
• Methods for ugba preparation vary
from one community to the other. In this method described by Obeta (1983), the
seeds are boiled in water for 16-18 hours to remove the tough testa. The
cotyledons are then sliced, boiled again for 30 minutes and left overnight in
water at room temperature. The sliced cotyledons are the washed in water and
packaged in leaves of banana.
• Another method described by Odunfa
and Oyeyiola (1985) and Odunfa (1986) shows that the seeds are boiled in water
over an open, first for 4-5 hours or even up to 12 hours. The cotyledons are
again boiled and washed several times tunes to remove bitter components in the
cotyledons and soaked for a period of 6 hours. The cotyledons are then cut into
long thin slices which are mixed with salt, put in a clean pot, covered and
fermented for up to 5days at room temperature, usually after 2-3 days of
fermentation, the sliced cotyledon are wrapped in banana leaves and tied
tightly.
• Njoku and Okemadu (1989) also
discovered another production method. The seeds are boiled for 5-8 hours, after
which the hard shells are removed. The cotyledons are cooled, washed and sliced
into 4-5×0.1-0.2cm slices. These are washed again and boiled for another 1-2
hours, cooled and soaked in water for about 10-12hours. They are washed and
allowed to drain for ½ -1 hour’ in a basket lined with banana leaves (Musa
Sapientum linn). They are then wrapped about 40-50g of slices using another
leaf (Mallotus Oppositifolius) and incubated for 72 hours at room temperature.
• Another method has been described by
Sokari and Wachukwu (1997). These workers said toasting the bean seeds in hot
(100ᵒᴄ) sand holding for a further 30 minutes at 100ᵒᴄ significantly improved
dehulhing. They also said that slicing to 1mm, boiling for 30 minutes and
soaking for 2hours removed the bitter taste associated with the seeds. They claimed
that the technique reduced the general production time by 2days and the quality
of ugba produced from this process was the same as that produced form the
rather more Cumbersome and time consuming traditional technique.
1.3 MICROORGANISMS
INVOLVED IN THE FERMENTATION
Several workers have investigated
the microorganisms involved in the fermentation of African oil bean seed. Only
bacteria are involved in the fermentation (Obeta, 1983; Odunfa and Oyeyiola,
1985; Ejiofor et al; 1987; Ogueke and Ariratu, 2004). The main fermentation
microorganisms have been identified to be proteolytic Bacilli species. (Obeta,
1983) which include;
BacillusSubtils (most predominant), B. Licheniformis,
B. Macrerans and Bacillus Circulans.
Some workers isolated yeasts Candida
Tropicalis and Geotrichum Candidum during fermentation (Ejiofor et al; 1987).
Since protein hydrolysis is the major biochemical change in ugba fermentation
(Oyeyiola, 1981), it can be assumed that the Bacillus sp. are the main
fermenting organism. Since the bean were boiled for hours before fermentation,
the microorganisms involved in the air, water, utensils, leaves used in
wrapping or by handling during the preparatory stages (Obeta 1983; Odunfa and
Oyeyiola, 1985).
Example: Staphylococcussp are more commonly associated with the skin and
hence are easily disseminated through handling. Also addition of salt would
selectively favour the growth of Staphylococcus and Micrococcus sp. which are
known to be salt tolerant (Adam and Moss, 1999)
1.4 MICROBIOLOGICAL
SAFETY OF UGBA
Various microbiological studied
conducted on ugba (Obeta, 1983; Odunfa and Oyeyiola, 1985; Ojueke and Aririatu,
2004) showed that food pathogens such as ClostridiumPerfringeris,
C. Botulinum, Salmonella,Shigella sp. and Vibrio
sp. have not been isolated from ugba. However, such bacteria as E. Coliand
Staphylococcus aureus have been isolated. These are bacteria capable of causing
food infections/poisoning. But since the preparation of the delicacy or
addition as condiments to soup involves heating, they was eliminated during the
process.
Azubuine and Isu (2006) studied the
fungal contamination of the fermenting product. They isolated Aspergillus flavus, A. niger, penicillium
Chrysogenum and Fusaruim sp. this posses a serious health risk as these are
these moulds observation of good manufacturing practice (GMP) during the
production. However, application of startar cultures and immobilized cells in
the fermentation process will eliminate these possibilities of contamination
with unwanted organisms. However, their numbers decreased with the increase in
the number of days of fermentation. This environment was most suitable for
their growth and toxin production especially with the increasing pH of the
fermenting slices into the alkaline region.
1.5 SPECIFIC
OBJECTIVES
• To isolate, characterized and
identify bacteria in raw and processed oil bean seed.
• To determine the physical parameters
of raw and processed oil bean seeds.
• To determine the chemical parameters
of raw and processed oil bean seeds.
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