COMPARATIVE STUDY OF MICRO-ORGANISM ASSOCIATED WITH THE SPOILAGE OF BANANA
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
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
CONCLUSION
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.
