Microbial Examination Of Spoiled Avocado Fruit

5 Chapters
|
54 Pages
|
7,239 Words

Microbial examination of spoiled avocado fruit is crucial for understanding the diverse array of microorganisms contributing to its decay. Avocado spoilage can result from the proliferation of bacteria, fungi, and yeast, which thrive in the fruit’s moist and nutrient-rich environment. Bacterial contaminants such as Pseudomonas, Bacillus, and Enterobacter species may induce enzymatic degradation and off-flavor development, while fungal species like Aspergillus, Penicillium, and Colletotrichum can lead to visible mold growth and structural breakdown. Additionally, yeast species like Candida and Saccharomyces contribute to fermentation processes, altering the texture and taste of the fruit. Employing microbiological techniques such as culture-based methods, molecular identification, and microscopy enables the identification and quantification of these spoilage microorganisms, aiding in the development of strategies to mitigate avocado deterioration and extend its shelf life.

ABSTRACT

Microbial examination of spoilt Avocado fruits was carried out to obtained the causal organism. A total of 60 avocado from Ogbete Main market and New market Enugu were examined by culturing on nutrient agar and sabourand dextrose agar (SM), for bacteria and fungi causing post – harvest spoilage on the fruits; six bacterial species and six fungal species were isolated. The bacteria include Erwinia SP (66.7%), Streptococcus sp, *25%), E. Coli (18.9%) and staphycoccus sp (33.3%), Pseudomonas sp (20%) and Chromobacterium sp (5%) has the lowest percentage occurrence, Erwinia sp, Pseudomonas sp and chromobacterium sp were found to be absent in the control. The fungi species, includes Aspergillus sp (50%), Pericillium sp (25%), Fusarium sp (16.6%), Rhisopus sp (13.3%), currularia sp (8.3%) and Rhoctorula sp (3.3%), were also kolated Avocado fruits from Ogbete main market were more contaminated than the avocado form the new market.

TABLE OF CONTENT

Title page
Certification
Dedication
Acknowledgement
List of Tables
List of figures
Abstract

CHAPTER ONE
Introduction
1.1 Background of study
1.2 Statement of problem
1.3 Aim and Objectives of the study
1.4 Hypothesis
1.5 Significance of the study
1.6 Limitation of the study

CHAPTER TWO
Literature review
2.1 The origin of Avocado fruits
2.2 Uses of avocado fruits
2.3 Preservation of avocado fruits
2.4 Ways avocado fruits can be prone to contamination
2.5 Microbial spoilage of avocado fruit
2.6 Control of bacterial and other disease of avocado fruits and fruits products
2.7 Some biochemical test for bacterial isolates

CHAPTER THREE
Materials and methods
3.1 Sample collection
3.2 Sterilization of media an material used
3.3 Preparation of media
3.4 Bacteria and fungi isolate from avocado fruits
3.5 Bacterial isolation and identification
3.6 Fungal isolation and identification
3.7 Lactophenole blue staining technique for fungi isolates
3.8 Staining techniques for bacteria isolates grains stain
3.9 Biochemical test for identification of bacteria isolates

CHAPTER FOUR
Results and discussion
4.1 Bacterial Examination
4.2 Fungi, examination

CHAPTER FIVE
Conclusion and recommendation
5.1 Conclusions
5.2 Recommendation
Reference

CHAPTER ONE

1.0 INTRODUCTION
1.1 BACKGROUND OF STUDY
The Avocado pear, Persea Americana is a tropical and sub tropical fruit tree, originated in central America or adjoining regions of North or South America. It has now spread to much of the near tropical world. The avocado is limited especially by its climatic requirements, with their race differences. It is also highly susceptible to drought injury. But excess soil moisture is equally fatal, encouraging the dread phytophthora root rot in most of the world, and where the fungus is unknown. Despite the high water activity of most fruits, the how PH leads to their spoilage being dominated by fungi, both yeast and moulds. Other common diseases of pears include the black spot or scab caused by as comycetes
Avocado fruits has being estimated that one fourth of all produced harvested is no consumed before spoilage (Salulche, 1974), spoilage of fresh fruits usually occurs during storage and transport and while wacting to be processed unlike many other foods fruits after picking and before processing are ‘a live’ of the products plus the normal ripering process complicate an independent discussion of the microbiological spoilage problems are really market diseases of these products:
Shape, varies from slightly obligate to highly elongate, an intermediate oval or pear shape is preferred. Yellow to purple or black.
The composition of the fruit influences the likely type of spoilage. thus bacteria soft rot is widespread for the most part among the fruits is limited to those that are not highly acid. Because most fruits are somewhat acid are fairly dry at the surface, and are deficient in B vitamins, mold are the most common causes of spoilage. The compositions too, must determine the particular kind of molds most likely to grow, thus avocado support a large, variety of fungal spoilage organisms and other kinds comparatively few.

1.2 STATEMENT OF PROBLEM
Micro-organisms are known to destroy fruits, thereby reducing the quantity for consumption and the profits desirable from fruits such as avocado. Many spot are noticed on pears which do change the taste when consumed.
Bacteria and fungi are harmful and useful living organisms. The spoilage of most fruits is always associated with bactera and fungi, many diseses of plants are associated with bacteria and fungi (Micro-organisms)
The adverse effect of bacteria in plants and fruits has resulted in shortage of avocado fruits for consumption. Revenue is lost by farmers and industries that uses avocado fruits as a raw materials for fruit juice due to the spoilage caused by micro-organisms.

1.3 AIM AND OBJECTIVES OF THE STUDY
Microbial examination of spoilt avocado fruits
To isolate and identify how micro-organism destroy avocado so as to guide producer and farmers on how to manage the fruits
To isolate and identify it those micro-organisms are responsible for the spoilage
To compare the extent of spoilage in the area of colelction (tree) with that of market

1.4 HYPOTHESIS
HO: Microbial organisms do not cause spoilage of avocado at either in the field or during exposure for sale.
Hg = Microorganisms (Fungi and Bacteria) are responsible for avocado spoilage.

1.5 SIGNIFICANCE OF THE STUDY
This study will be useful to farmers, fruit juice industries and consumers of avocado fruits. T he outcome of this research will guide users of avocado fruit on the best method of preserving to avoid spoilage, the research work also will add to the literature and information existing about avocado for student and companies that uses avocado as raw materials for the production of fruit juice

1.6 LIMITATION OF THE STUDY
There are many or different type of microorganism that causes spoilage in avocado fruit or fruits in general, focus is made only on fungi and bacterial because they are the major organisms associated with spoilage in avocado fruits.

SIMILAR PROJECT TOPICS:
Save/Share This On Social Media:
MORE DESCRIPTION:

Spoilage of avocado fruit can occur due to various microbial factors. The most common microbes responsible for spoiling avocados include bacteria, fungi, and yeasts. Here’s a brief overview of how these microbes can contribute to the spoilage of avocado fruit:

  1. Bacteria: Several types of bacteria can lead to the spoilage of avocados. These bacteria can cause the fruit to become slimy, discolored, and develop off-putting odors. Some common spoilage bacteria include Pseudomonas, Enterobacter, and Acinetobacter species. Bacterial growth is more likely when avocados are stored in conditions with high humidity or if the fruit has been damaged, as bacteria can enter through wounds or cracks.
  2. Fungi: Fungi are a major cause of spoilage in avocados. Mold and mildew are the most common fungi associated with avocado spoilage. Mold growth often appears as fuzzy, black, or green spots on the fruit’s skin or flesh. The most common mold species responsible for avocado spoilage is typically from the genera Penicillium and Aspergillus.
  3. Yeasts: Yeasts can also contribute to avocado spoilage. They tend to grow on the fruit’s surface, especially when there is excess moisture. Yeast growth can result in the formation of a film or slime on the avocado, making it unpalatable.

To prevent microbial spoilage of avocados, it’s essential to follow proper storage and handling practices:

  1. Refrigeration: Storing avocados in the refrigerator can slow down microbial growth. It’s best to keep avocados at temperatures between 40-45°F (4-7°C).
  2. Moisture Control: Avocado fruit should be kept dry and not exposed to excess moisture. Moisture promotes the growth of fungi and yeasts.
  3. Handling: Handle avocados carefully to avoid bruising or damaging the fruit, as this can create entry points for bacteria.
  4. Isolation: Store avocados away from other fruits and vegetables, as some fruits release ethylene gas, which can accelerate ripening and spoilage of avocados.
  5. Regular Inspection: Check avocados regularly for signs of spoilage. Remove any spoiled fruit to prevent the spread of microbes to healthy ones.
  6. Use within a Reasonable Timeframe: Avocado fruit is perishable and can spoil relatively quickly once it ripens. Use them within a few days of ripening to reduce the risk of spoilage.

By following these guidelines, you can minimize the risk of microbial spoilage and enjoy fresh, delicious avocados.