ABSTRACT
The
comparative study of microorganisms associated with the spoilage of banana.
“Banana is a general term embracing a number of species or hybrid in the genus
musa, family bacteria organisms, small pieces of decayed tissue from the
leading edge of the lesion was transferred, by means of sterile techniques, to
the SDA contained in covered dishes and incubated at room temperature (28-370c). The fungal and bacterial growth visible
within 2-7 days. Each observed fungal
and bacterial growth based on their
morphological and cultural microscopic examination and this microscopic
examination was done using the lactophenol
staining technique. Some
organisms like Erwinia species has been incriminated as pathogen, saprophyte or
constituent of epiphyic flora of plants.
TABLE OF CONTENTS
Title page
Certification
Dedication
Acknowledgement
Abstract
Table of content
CHAPTER ONE
1.1 INTRODUCTION
1.2 AIM
AND OBJECTIVE
1.3 SIGNIFICANCE
OF STDY
1.4 STATEMENT
OF PROBLEM
1.5 LIMITATION
1.6 HYPOTHESIS
CHAPTER TWO
2.0 LITERATURE
REVIEW
2.2 MOLDS
2.3 YEAST
2.4 BACTERIA
2.5 BACTERIAL
SPOILAGE OF BANANA
2.6 FUNGAL
SPOILAGE OF BANANA
2.7 OTHER
FUNGAL SPOILAGE OF BANANA
2.8 CONTROL
OF BACTERIAL AND FUNGAL DISEASES
CHAPTER THREE
3.0 MATERIALS
AND METHOD
3.1 STERILIZATION
OF MATERIALS AND MEDIA USED
3.2
PREPARATION OF SABORAUD DEXTTROS AGAR (SDA)
3.3
PREPARATION OF NUTRIENT AGAR
3.4
BACTERIAL/FUNGAL ISOLATION BANANA FRUIT
3.5
BACTERIAL ISOLATION AND IDENTIFICATION
3.6
FUNGAL ISOLAATION AND IDENTIFICATION
3.7
STAININMG TECHNIQUE FOR BACTERIAL ISOLATES
3.8
ISOLATION OF YEATS AND MOLD
CHAPTER FOUR
4.0 RESULTS
4.1 BACTERIAL
EXAMINATION
4.2 FUNGI
EXAMINATION
CHAPTER FIVE
5.0 DISCUSSION
5.1 CONCLUSION
5.2 RECOMMENDATION
REFERENCES
LIST OF TABLES
TABLE I: BIOCHEMICAL
ISOLATES FOR BACTERIAL
TABLE II: FUNGI
ISOLATE
TABLE III: BIOCHEMICAL TEST FOR YEAST ISOLATED
TABLE IV: SOURCES OF COLLECTION OF THE FRUITS
TABLE V: ORGANISMS ISOLATED AND THEIR FREQUENCIES
LIST OF FIGURES
FIGURE I: HOW
ERWINIA SPECIE IS THE HIGHEST OCCURRENCE
FIGURE II: HOW ASPERFILLUS SPECIE
IS THE HIGHEST OCCURRENCE
FIGURE III: THE LEAST OCCURRENCE IS
CHROMOBACTERIUM SPECIE
FIGURE IV: THE HIGHEST AND ATHE
LEAST OCCURENCES WERE ASPERGILLUS SPECIE AND RHODOTORULA SPECXIE
FIGURE V: THE GRAPHICAL
REPRESENTATION OF THE FREQUENCY OF OCCURRENCE OF THE MICROORGANISM FOUND IN THE
TESTED BANANA.
FIGURE VI: SHOWS THE FREQUENCY OF
OCCURRENCE OF THE MICRO-ORGANISM FOUND IN THE SPOILT BANANA FRUITS.
CHAPTER ONE
1.1 INTRODUCTION
Banana may
be defined as a personal seed plant that produces an edible fruits, usually
seedless, belong to the species M.
acuminata, or are hybrids M. acuminata, M. balbisnna. They are perennial herbs with long, the bases
of these leaves (petioles) remain tightyly fused and form the trunk
(Pseudostem) of a plant 2-9m (6-30-ft) in height (Ploetz, 1994),
“Banana” is a general term embracing a
number of species or hybrids in the genus musa, family musceae. In some areas
of the world bananas are grown only as ornamental plants or for fiber.
It is found in tropical regions. The banana is monocarpic, flowering and
setting fruit once before sit dies. The
inflorescence protective flag leaf. The
flower stalk of most banana varieties is
positively geotropic and bends from the vertical until its stip points towards
vertical flower stalks are from 30 – 90 cm (1-3ft) along, tapered and covered
in a sheath of over- lapparing bracks the flower are parthenogenic
(self-fertile). And occur in group of
12-20 beneath the bracks.
At first, individual fruiots called
fingers, make up the groups (hands) which are arranged in a spiral around the
flower stalk, forming a bunch.
At fruit set, a healthy banana plant
will have 8-12 leaves, fruits mature in 60-100 days after flowers first appears
depending on the season and cultivan.
New banana plants arise as suckers from an underground rhizone. As old planted die and new sucher are formed
the rhizome expands and is called a mat.
Banana are propagated by suckens, pieces of the Bluzome and by tissue
culture (Ploetz 1994)
USES
Bananas
contain about 74% waterm 23% carbohydrate, 1% protein and 0.5 %. A 4 – ounce banana without the peel is a good
source of vitamin Bb, Potassium, and
fiber.
Banana
fruit may be eaten raw or as a cooked
vegetable. The fruit can also be
processed for a number of food products.
Ripe fruits can be pulped for puree
for in a variety of products including ice cream, yoghurt, cake, bread, nectar,
and baby food. Ripe banabas can be dried
and eaten, or sliced canned with syrup, and used in bakery products, fruits
salads and stoppings. Green (unripened)
bananas can be sliced and fried as chips. Whole green fruits can also be dried
and ground into flour. Vinegar and alcoholic beverages can be made from
fermented ripe bananas. Other parts of the banana plant are consumed besides
the fruits. The heart of the growing pseudostem is eaten in India. In Southeast Asia,
the male bud is eaten as a boiled vegetable.
The banana leaves are not eaten but
may be used for wrapping food in cooling. The banana foliage and pseudostems
are used as cattle feed during dry periods in some banana producing areas. Culled bananas are used sto feed cattle and
hogs. Bananas are a good energy source
but need to be supplemented with
protein. But not all
micro-organisms associateeed with fruits are harmless”. This
includes the lactic acid bacteria, coryne forms, pseudomonads,
xanthomonads micrococci, amny fungi and
coliforms. These microorganisms do play
an important role in the spoilage of food and dictate the shelf life of fresh
fruits. Most healthy raw produce will have on them anywhere from a few thousand to millions of miucroorganisms
per gram. The presence of many of these
microorganisms is a concern for causing product spoilage.
Food spoilage is a major problems in
all societies especially fruits, because
they provide nutrients for us, also are excellent environment for the
growth of micro-organisms. Microbial
growth as well as spoilage is controlled
by factor related to the food itself or intrinsic factor and also to
theenvironment where the food is being stored or what are described as extrinsic factors. Food composition is critical intrinsic factor
that influences microbial growth, if a food consider primarily of carbohydrates, spoilage does not result in
major odours. Thus, foods such as some
fruits e.g. banana show spoilage by fungal growth. Also, PH of a food also is critical because a
low PH a food also is critical because a low PH favours the growth of yeasts
and mold. This is the case in banana
fruit because it has PH of 2-5 physical structure of a food also can
affected the course and extension of spoilage.
Banana fruits has outer skin
(peels) that project them from spoilage.
Often, spoilage micro-organisms have
specialized enzymes that help them weaken and penetrate protective peels,
especially after the fruits has been bruised.
Temperature and relative humidity are important extrinsic factors in determining
whether a fruit (banana) will spoil. At
higher relative humilities, microbial growth is
initiated more rapidly even at lower temperatures.
The atmosphere in which the fruit is
stored is also important as this plays a crucial role in its spoilage. Because fruits are such excellent sources of
nutrients, If the intrinsic and extrinsic conditions are appropriate,
micro-organisms grow rapidly and make what once was an attractive and appealing
fruits into a sour, foul-smelling or fungus – covered mass suitable only for
the garbage car.
Microbial
spoilage in Banana can lead to visible challenges, including a variety of
colours caused by spoilage organisms.
Bacteria do not seem important in the initial spoilage of whole fruits
like banana instead such spoilage often is initiated by molds.
These organisms have enzymes that contribute to the weakening and
penetration of the protective outer skin.
Many microorganisms have been isolated from banana, actually spoilt
banana. These micro-organisms have been associated with moko disease, or moko
de Guineo, or marchites bacteriana, is caused by the bacterium, pseudomonas
solanacearum, resulting in internal decay.
It has become one of the western
hemisphere and has seriously reduced production in the leading area as of Colombia. It
attacks Heliconia species as well. It is
transmitted by insects, machetes and with the roots of sick plants. There are said to be 4 different types
transmitted by different means. Efforts
at control include covering the male and bud with plastic to prevent insects from
visiting its mucilaginous excretion, debudding, disinfecting of cutting
tools with formalde hyde in water 1:3,
disinfection of planning material;
disposal of infected fruits and plant parts: infection of herbicides into
seemingly healthy neighbouring plants. if The organism is vriant SFR, all
adjacent plants. If the organism is variant SFR, all adjacent plants within a
radius replanted for 10 to 12 months for this variant persists in the soil that
long. If it is variant B, the plants
within 32.8 ft (10m) must bee injected and the area not replanted for 18
months.
In either case the soil must be kept
clear of broad leaved weeds that may serve as hosts. In Colombia, there are 12 species of
weeds that serve as hosts or “carriers:” but only 4 of these are themselves
susceptible to the disease. Crop
rotation is sometimes resorted to the only sure, defense is to plant resistant
cultivans. Such as the ‘pelipita’
plantain.
Black-end arises from infection by the
fungus arises from infectrion by the fungus Glocosporium musarum, of which
Glomerella cingulata is the perfect form.
It causes authracuose on the plant and attacks the stalk and stalk – end
of the fruits forming dark, sunken
lesions on the peel, soon penetrating the fresh and developing dark, watery,
soft area in severe cases, the entire skin turns black and the flesh rats. Very young fruits shrived and mummify. This
fungus is often responsible for the rotting of bananas in storage. Immersing the green fruits in hot water. 131of
(55oc) for 2 minutes before ripening greatly, reduces spoilage.
Sigar-tip rot, or cigan-end disease,
stachylidium (verticillium) theobromae begins in the flowers and extends to the
tips of the fruits and turns sthem darks the peel darknens, the flesh becomes
Fibrous. One remedy is to cut off withered flowers as soon as the fruits are
formed and apply copper fungicides to the cut surfaces. Unlike most other fruits, banana develop
their best eating quantity after they are harvested. This allows bananas to be
shipped great distances. Almost our
entire supply of banabas, available year-round is imported from central and
south america. Bananas are sensitive to cool temperature and
will be induced in temperatures below 550f for this reason, they
should never be kept in the refrigerator.
The ideal temperature for ripening bananas is between 60 and 700f. higher temperature cause them to repen too
rapidly.
However, Bananas which are firm,
bright in appearance, and free from repeness is indicated by skin colour. Best eating quality has been reached when the
solid yellow colour is specked with brown.
At this stage, the flesh is mellow and
the flavour is fully developed. Bananas
with green stips or with practically no yellow colour have not developed their
full flavour potential.
1.2 AIM AND OBJECTIVES
1.
it shows the amount of bacteria present in the decay
of banana
2.
it also shows the amount of yeast and mold present in
the decay of banana
3.
it provides a basic understanding of the physical,
chemical and microbiological principles underlying the psreervation of foods
and also provide as a basic understanding of the study of food microbiology
from farm to consumer.
4.
It provide students with an understanding of the
physical and chemical characteristics which influence the formation, stability
and texture of food systems
1.3 SIGNIFICANCE
OF STUDY
This study is done to find out how
similar or different microorganisms associated with the spoilage of bananas
are: it brings to fore a good number of
microorganisms associated with that or bring about the spoilage of
banana (musa acuminata). The
significance of this study can never and will never be over emphasized. This is because banana is a fruit of choice
and spoils easily. As a result of this,
a knowledge of the microorganisms that are involved in its (banana) spoilage is
essential.
Also, this study gives an insight into
the conditi ons as well as factors that result in the spoilage of this attractive fruit, not to mention the nature
or group of microorganisms that are associated with such a fruit. The significance of this study is seen in the
light of having a good understanding and showing the comparism of the spoilage
microorganisms of banana.
1.4
STATEMENT
OF PROBLEMS
A study of
this nature must have problems which result in it. This problem will result from how these
microorganisms are being associated with
the spoilage of banana a fruit and cause decay to these banana and make it
undesirable for human consumption. This
microorganisms associated with the
spoilage of banana includes yeast and mold, {uedomonas species, micrococcus
species, bacterial and fungal
species. Looking at many banana sold in
the market today, most of them are infected with these microorganisms or other
microorganisms like the soft rot, crown rot bacteria and soft rots which infect
and make these fruit unattractive for
human consumption and may cause problems to human being as well as animal.
1.5 LIMITATION OF STUDY
As a result of time factor,
the study was constrained to fit within the stipulated time limit. Due to this fact, this study was limited only
in stored spoilt and decaying banana purchased from different market places.
1.6 HYPOTHESIS
Ho = Microorganisms are
associated with the spoilage of banana
HI = Microorganisms are
not associated with the spoilage of banana.
Login To Comment