ABSTRACT
Fungi spoilage organisms
are silently invading acidifying, fermenting, discoloring, and disintegrating
microbes that render corn (zea mays) unpalatable and
unsafe. Fungi spoilage is caused by two factors, (biotic) living which
includes insects, birds, rodents and microorganisms and (non-biotic) non-living
which includes temperature, humidity and time. Two samples of spoilt
corn, red (treated) and white were taken from the store respectively for
investigation to ascertain the microorganism associated with the spoilage of
the corn. Attention was focused on fungi. Different methods were
used in the identification and five genera were isolated. Mucor spp occurred
with a frequency of approximately 6%, Aspergillus
spp 9%, Rhizopus
spp 15%, Penicillium
spp 33% and Fusarium
spp. 36%. Fusarium
spp was most frequent in occurrence in both samples.
TABLE OF CONTENTS
CHAPTER
ONE
INTRODUCTION
1.1
Background of the study
1.2
Statement of problem
1.3
Aim and objectives of the study
1.4
Hypothesis
1.5
Justification of the study
1.6
Significance of study
1.7
Limitation of the study
CHAPTER
TWO
LITERATURE
2.1
Origin of maize pad
2.2
Structure of maize grain
2.3
Chemical composition of maize grain
2.4
Uses of maize pap
2.5
Chemical changes in stored pap (ogi)
2.6
Nutrition changes in stored pap
2.7
Microorganisms associated with stored pap
CHAPTER
THREE
MATERIALS AND METHOD
3.1
Collection of sample
3.2
Materials and equipments used
3.3
Media and reagents used
3.4
Preparation of pap (ogi)
3.5
Quantitative analysis of microorganisms
3.5.1
Serial dilution
3.5.2
Culturing technique
3.6
Isolation of bacteria
3.7
Characterization of isolate
3.8
Biochemical test for identification of
microorganisms
3.9
Identification of fungi
CHAPTER
FOUR
RESULTANDDISCUSSION
CHAPTER FIVE
5.1
Conclusion
5.2
Recommendation
References
Appendix
CHAPTER ONE
INTRODUCTION
1.1 BACKGROUND OF THE STUDY
Cereals
have been known to man from the earliest times porridge prepared from cereals
are eaten in different parts o the
world, especially in developing countries where they may present the basic
diet. This porridge could be baked to
enhance the taste, quality and improve digestibility (Oke 1967, Adeniyi and
Potter 1978, Uno and field 1981).
Corn (zea mays) is one of cereals which
is an important raw material in human diet.
In Nigeria, maize is grown mainly in the southern part of Nigeria while
sorghum (Sorghum bicolor) and millet (perinisetum typhoideum) are grown in the
northern part of the country. A fermented cereal product is known as
paplogi). Corn is processed into
traditional food such as paplogi) Umo and fields 1981).
Pap is a fermented non-alcoholic starchy
food and is a major staple food widely consumed in west Africa. It is a sour fine past beverage which when
cooked produces a thin semi solid porridge. Pap (Ogi) porridge has a smooth
texture and a sour taste resembling that of yoghurt,. In Nigeria, some states such as Anambra, Imo,
Enugu and Abia refer to it as Akamu but Ogi is a Yoruba name but most state of
Nigeria, it refers to maize pap. On the
other hand, sorghum pap is known as Ogi baba while millet pap is known as Ogi
gero in Yoruba (Banigi 1977, Onyekwere and Akinrele 1977).
Pap logi) can be consumed with variety of
other product including with bread, steamed been cake (moi-moi), fried bean
cake (Akara), fried yam and plantain etc.
it is used as a main meal for adult and sick patients and it is suitable
for breakfast, lunch and dinner. Pap is
widely used as the first native food given to babies at wearing to supplement
breast milk and is a major breakfast cereal for pre-school children and adults. It is consumed as a main meal for
convalescing patients because it can easily be digested. As a wearing food, it is utilized mainly by
low income earners category, it is estimated that about 25 million or more
adults eat it about 4-5 days weakly (Banigo 1972). Milk and sugar may be added to improved the
taske and nutritional quality. Pap is
cooked and turned into a stiff gel called Agidi which is similar to kenkey, a
fermented shanian product (Muller 1988, withby 1968). Some Yoruba indigens beliwved that pap is
capable of stimulating the production of breast milk in Nursing mother (Bassir
1962). However, there has been no qualitative evidence of support
of this belief.
In spite of it’s important in the Nigeria
diet, pap manufacture is essential a home based industry. There are at present no large scale factory
operation for the production of pap. The
manufacture is carried out on a small scale by some house wives as a commercial
venture in many parts of the country.
The cleaned grain free of dirt and impurities steeped in eastern ware,
plastic or enamel pot for 1-3 days at room temperature, this is followed by wet
milling and sieving. Twenty-four (24)
hours of sleeping leads to a greater depletion of the fermentable
carbohydrate. After sieving, the coarse
material obtained is wash with water to separate more of the starch. The filtered slurry is allowed to sediment
and undergo further fermentation for 1-2 days at room temperature. The coarse matter which is separated is used ad
animal feed while the sediment (Pap) is boiled to obtain.
1.2 STATEMENT
OF PROBLEM
Corn
(Zea Mays) is a grain grown
by farmers in various parts of the world especially in Africa. Its
spoilage most times limits its availability to consumers and causes economic
waste to farmers. Corn is mostly spoiled by fungi. The identification and
characterization of these spoilage organisms will go a long way to profer
solution on matter how little to this problem of corn spoilage.
1.3 AIM
AND OBJECTIVES OF THE STDU
The
aim of this study is to isolate and characterize fungi associated with spoilage
of corn.
SPECIFIC OBJECTIVES ARE
i.
To isolate and
characterize bacterial contaminants from stored pap
ii.
To isolate and characterize fungal
contaminants from spoilage of corn
1.4 HYPOTHESIS
HI: Fungi
are involved in the fermentation and storage of corn
1.5 JUSTIFICATION OF THE STUDY
Not very much work has
been done in this in recent times, with reference to the microbiology of the
process. Some of the earliest workdone
in this include those of Akiurele (1970-1977) and Barigo (1969, 1970, 1972, 1977).
1.6 SIGNIFICANCE OF STUDY
The
study will help in the acquisition of the knowledge of fungi associated or
involved in the spoilage of corn, factors that enhance spoilage of corn and the
risk involved in the consumption of spoilt corn.
1.7 LIMITATION OF THE STUDY
This work is limited to
viable microorganism present in the corn (zea mays) only which will be
purchased from Ogbete in the Enugu Area.