Description
ABSTRACT
The cold storage structure was modified and evaluated for the storage of fruits and vegetables at the department of agricultural and bio-environment engineering of Kwara State polytechnic, Ilorin; the cold storage structure consists of the following components; compressor, evaporator, condenser, accumulator, dryer, etc. the variable factors are temperature and relative humidity. The cold storage structure was tested with the following fruits; watermelon, cucumber, tomatoes and apple .these samples were stored under two conditions (ambient and cold storage) for period of three days which was monitored at four hours intervals with constant supply of electricity. Using a constant relative humidity of 85% throughout the experiment. The result revealed and average physiological weight loss of the samples on both ambient and cold storage, which are 7.8g, 3.3g, 21.3, 10.5 for ambient samples while3.5g, 0.8, 3.8, 2.6 for cold storage sample respectively.
The cold storage structureperforms satisfactorily when evaluated and it’s recommended for the storage of fruits under controlled conditions.
TABLE OF CONTENTS
Title Page
Certification i
Dedication ii
Acknowledgement iii
Abstract v
Table of Content vi
CHAPTER ONE: INTRODUCTION
1.1 Background of the Study 1
1.2 Problems Statement 2
1.3 Aims and objective of the project 2
1.4 Justification of the Project 3
1.5 The Scope of the Project Work 3
CHAPTER TWO: LITERATURE REVIEW
2.1 Development of Cold Room Structure for fruit and Vegetable 4
2.2 Harvest Handling and Transport of fruit and Vegetable 5
2.2.1 Harvesting Principle of fruit and vegetable 5
2.2.2 Handling of fruit and Vegetable 5
2.2.3 Transport of Fruit and Vegetable 5
2.3 Storage Guidelines for Fruit and Vegetable 6
2.4 Heat Load Factor Normally Considered in Cold Storage Design 6
2.5 Expected Storage Life 7
2.6. Factors Affecting the Performance of Storage Structure 7
2.7. Principle of Refrigeration 10
2.7.1 Evaporation 11
2.7.2 Compressor 11
2.7.3 Condenser 12
2.8 Reviews on Existing Work on a Cold Storage Structure 12
CHAPTER THREE: MATERIALS AND METHOD
3.1 Modified Area on the cold Storage. 14
3.2 Description of the Cold Room Storage System. 15
3.3 Designed Consideration 17
3.3.1 Cold Storage system 17
3.3.2 Capacity of the cold storage system 17
3.3.3 Power Requirement for cold storage system 17
3.3.4 Nature of Fruits and vegetables 18
3.4 Design Calculation and Analysis 18
3.4.1 Capacity of the Cooling Chamber 18
3.4.2 Heat transfer Analysis of the System 19
3.5 Materials Selection Consideration 20
3.5.1 Strength 20
3.5.2 Durability 20
3.5.3 Rigidity 20
3.5.4 Thermal Properties 21
3.5.5 Food safety 21
3.5.6 Availability of Materials 21
3.5.7 Gas Selection 21
3.6 Installation procedure and assemble 21
3.6.1 Application of the Installation 21
3.7 Working Principle of Cold Storage System 23
3.8 Cost Analysis 23
3.8 Performance Evaluation 25
3.8 K.1 Source of Material 25
3.8.2 Sample Preparation 26
3.8.3 Experimental Procedure 26
3.8.4 Output Parameters 26
CHAPTER FOUR: DATA ANALYSIS AND RESULTS
4.0 Results and Discussion 30
4.1 Performance Evaluation, Result and Discussion 30
4.2 Discussions 31
4.2.1 Discussion on average weight and temperature of sample both in cold storage and at
mbient condition 31
4.2.2 Discussion on Physiological Weight Loss of Samples 32
4.2.3 Discussion on temperature against time interval in cold storage and
ambient condition 32
CHAPTER FIVE: CONCLUSION AND RECOMMENDATION
5.1 Conclusion 45
5.2 Recommendation 46
LIST OF FIGURES
FIGURES
Description
4.1 Effect of weight loss on daily time for okro
4.2 Effect of weight loss on daily time for pear
4.3 Effect of weight loss on daily time for water leaf
4.4 Effect of weight loss on daily time for bell pepper
4.5 Effect of temperature against time interval in the cold storage and under ambient condition
LIST OF TABLES
TABLES
Description
2.1 General problems of each fruits and vegetables group at each handling
3.1 Bill of engineering measurement and evaluation ( BEME)
4.1 Average weight and temperature of samples both in cold storage and ambient condition
4.2 Average value of physiological weight loss of samples
4.3 Data obtained from cold storage and ambient temperature against time
CHAPTER ONE
INTRODUCTION
1.1 Background of the Study
Fruits and vegetables are of great nutritional value. They are important sources of vitamins and minerals thus, essential components of human diet. Consequent upon this, there had been increased trade or commerce activities surrounding these commodities. Vegetable production forms a substantial percentage about 25% of the major food crops cultivated in the tropics and so it is the source of livelihood for a considerable section of the population (Idah, 2007).
Fruits and vegetables in their fresh forms contain high percentage of water. They are living and hence carry out their physiological function of respiration thereby absorbing and releasing gases and other materials from and to their environment. These activities lead to their deterioration in transit and storage, which is more rapid under conditions of high temperature and humidity. As a result, heavy losses are encountered in these produce. Fruit and vegetable are generally classified as perishable crop if not quickly preserved when harvest they shrivel wither or rot away rapidly especially under hot condition. Highly perishable ones likes’ leafy vegetables, tomatoes asparagus etc. even in storage have a recommended refrigeration storage life of less than one week (Ndukwu, 2011).
Fruit and vegetable are fundamentally different from most other produce which is sold stored in the fresh (unfroze) state in that they are living they respires thus suitable ventilation must be provided. During cold storage they undergo characteristic change of senescence and of ripening of fruit (Cantwell, 2001).
Storage has been developed to ensure the supply of an agriculture product to consumers with minimized quality degradation. Orderly marketing of perishable commodities often requires some storage to balance day- to- day fluctuation between product harvest and sales or for long term storage to extend market period. (Tripath and Bhat 2000).
Cold room storage generally tends to depict the views and ideas of a system that embarks on a continual extraction of heat from its body whose temperature is already below its surrounding temperature. Thus, refrigeration inevitably is the only means of preserving food in its original freshness. (Ugwuet al, 2012).
1.2 Problem Statement
Lack of storage facilities is one of the major challenges facing perishable produce in Nigeria and result in higher post-harvest losses. Temperature plays an important role in post-harvest handling of perishable produce since it affect most of the enzymatic reaction in harvesting produce cause an increase in the rate of deterioration processing. Cooling of perishable product immediately after harvest and maintain the cold chain along the supply chain is key in slowing down the deteriorative process hence there is a need to develop a cold room that will reduce deterioration of fruits and vegetable and extend their shelf life.
1.3 Aim and Objective of the Project Work
The aim of the study is to enhance good storage facilities for fruits and vegetables under a cold room storage structure in order to prolong their shelf life and retain the quality of this perishable product for a specific period of time.
The specific objectives:
- To modify a cold room storage structure.
- To install temperature and relative humidity controller and change some component parts of the cold storage.
- To evaluate its performance on selected fruits and vegetables in terms of cooling rates, physiological weight loss, colour changes and firmness
1.4 Justification of the Project
Modification of the existing cold storage structure will bring about the improvement for spacious storing of fruit and vegetables, and proper management of cold room storage with regards to temperature, relative humidity level, air circulation, adequate space between storage bin; prolong the shelf life of all agricultural product and convince the investors on the effective performance of a cold room as a place which can retain and preserve the nutritional quality and value of perishable product over a long period of time.
1.5 Scope of the Project
The scope of this project is limited to modification, installation and performance evaluation of the cold storage structure, using okra , pear, water leaf and bell pepper under two condition (ambient and cold storage).
CHAPTER FIVE
CONCLUSION AND RECOMMENDATION
5.1 CONCLUSION
A cold storage system was modified for performance and the following conclusion were drawn;
- The percentage weight loss (PWL) varied between 0 – 41.7 . Maximum weight loss was found in ambient condition where as minimum (0.06 ) was found in the cold storage system. The percentage weight loss was found increased with increase in storage period for both cold storage system and ambient condition,
- The minimum temperature of 1.40C was recorded in the cold storage system when average ambient temperature was 27.70 The temperature drops from 29 to 1.40C was found in case of cold storage system throughout the storage period
- The relative humidity of 85 was recorded in the cold storage system
- Cold storage system proved to be the best for prolonging and extending the shelf life of fruits and vegetables in it.
- Cold storage system research would help innovative farmers who yearn for modern storage methods by storing quality produce to enable them to have access to various market opportunities.
5.2 Recommendation
The following are hereby recommended for further improvement on the cold storage structure.
- Increase in insulation thickness in order to increase the thermal resistance of the wall to the flow of outside heart which may result in lowering the fooling of cold storage. may serve as a source of leakage.
- A drain should be provided outside the cold room to ease flow of defrosts water. If this space is provides, it may also serves as a vent for taking indoor temperature record without frequent opening of door which can thus increase the performance of the cold room storage structure.
