ABSTRACT
In ensuring the prevention of losses when raw agricultural product is in the peak of its season and to assure safety, effective method of packaging and processing is highly indispensable. This study researched into the property of stored tomato concentrate packed in glass bottle, plastic bottle and polyethylene stored in the presence of light and in the absence of sunlight. Tomato concentrate was produced by concentrating tomato pulp using filtration and evaporation to ensure minimum heat treatment. Physico-chemical analyses were carried out to determine the total titratable acidity, pH, total solids, total carotene content and lycopene content. Microbial analyses were also carried out. The result showed that all samples showed a significant increase in pH with decrease in total titratable acidity while the study was on going. The range of pH change during the storage was from 3.86 in the control sample to 4.41 in the sample stored at atmospheric condition. At room storage condition, the trend of change in total carotene was from 3.78mg/100g in sample stored in glass bottle under room condition to 1.91mg/100g in the sample stored in polyethylene pack at atmospheric condition. For lycopene, the range of value recorded throughout the period of storage in all the sample was from 3.17mg/100g in glass bottle stored under room condition, to 1.49mg/100g in the sample stored in plastic package at atmospheric condition. Total carotene content, lycopene content of all the samples decreased with increase in the time of storage, the brix value however remained fairly constant throughout the period of storage. The highest moisture content was recorded in the sample stored under room condition (92.56%) during week ten while the lowest was recorded in the sample stored in polyethylene under atmospheric condition during the twelfth week. There was also a slight reduction in the colour property of the samples stored in the dark while change in the ∆E value was pronounced in those samples stored in the presence of light. Highest number colony forming unit was recorded in the samples stored in polyethylene (16*10^3 CFU) while the lowest (10*10^3CFU) was recorded in the samples stored in the glass bottles Also, greatest loss of lycopene and carotene was recorded in those samples stored in the presence of light. While those packed in the glass retained highest concentration of lycopene and total carotene, those samples stored in the presence of light inside plastic package retained lycopene the least at the end of twelve weeks. Generally, samples stored in the dark under room condition retained their nutrients more than those stored under atmospheric condition and can be stored up to twelve weeks while those in the presence of light would have loss most of their colour property before week ten. Tomato concentrate therefore can be stored effectively even using polyethylene package in the absence of direct light.
Keywords: Tomato, Storage, Properties, Atmosphere, Room, Range, significance, physicochemical.
TABLE OF CONTENT
Title Page
Certification………..…………………………………………………………………………ii
Dedication……………………………………………………………………………………iii
Acknowledgement……………………………………………………………………………iv
Abstract….……………………………………………………………………………………v
Table of Content…………………………………………………………………………vi - viii
List of Figures………………………………………………………………………………ix
List of Tables…………………………………………………………………………………x
CHAPTER ONE 1 – 5
1.0: Introduction…………………………………………………………………...1
1.1: Cultivation of tomato fruits …………………………………………………..1 – 2
1.2: Tomato and tomato products………………………………………………….2 – 3
1.3: Problem statement……………………………………………………………....4
1.4: Objective of the project…………………………………………………………4 – 5
vii 1.5: Justification of Research objective……………………………………………...5
CHAPTER TWO 6 – 30
2.0: Background……………………………………………………………………...6
2.1.0: Tomato Quality Deterioration…………………………………………………7 – 8
2.1.1: Physiological response…………………………………………………..…….8
2.1.2: Respiration…………………………………………………………………….8 – 9
2.1.3: Transpiration…………….....................……………………………………….9 - 10
2.1.4: Ethylene……………………………………………………………………….10 – 11
2.1.5: Physiological disorder……………………………………………….………..11 – 12
2.1.6: Mechanical damage…………………...………………………….………….12 – 13
2.1.7: Microbiological disorder……………………………………………………13 – 14
2.2: Concentration as applied to tomato processing……………………………..14 – 16
2.3.0: Processing of tomato fruits………………………………………………….16 – 18
2.3.1: Unit operation in tomato concentrates preparation…………………………..19
2.3.2: Harvesting and Storage process………………………………………………20
2.3.3: Washing and cleaning process……………………………………………......20
2.3.4: Sorting and grading…………………………………………………………...21
2.3.5: Pulping and Break process……………………………………………………22 – 23
viii 2.3.6: Primary finishing process……………………………………………………..23 – 24
2.3.7: Secondary finishing process…………………………………………………..24
2.4.0: Evaporation as applied in tomato processing………………………………….24 – 25
2.4.1: Tomato juice evaporation………………………………………………………25
2.4.2: Quality parameters influenced by thermal processing………………………….25
2.4.2.1: Colour…………………………………………………………………………26
2.4.2.2: Consistency……………………………………………………………………27
2.4.2.3: Flavour………………………………………………………………………...27 – 28
2.5.0: Nutritional value of tomato and tomato products……………………………….28 - 30
CHAPTER THREE 31 - 38
3.0: Materials and methodology………………………………………...………….31
3.1: Preparation of the sample…………………………………………….………..31
3.1.1: Processing of the fruit…………………………………………….………….31
3.1.2: Preparation of the pulp…………………………………………….…………31
3.1.3: Preparation of packaging materials…………………………………………..31 – 32
3.1.4: concentration…………………………………………………………………32 - 33
3.2.0: Storage………..............................................…………………………………34
3.2.1: Determination of properties of stored tomato concentrates…………………..34
ix 3.2.1.1: Determination of total titratable acidity……………………………………..34 – 35
3.2.1.2: Determination of total soluble solids………………………………………35
3.2.1.3: Determination of Sugar acid ratio………………………………………….35
3.2.1.4: Determination of pH………………………………………………………..36
3.2.1.5: Determination of lycopene………………………………………………….36
3.2.1.6: Determination of total carotene……………………………………………...36 – 37
3.2.1.7: Determination of colour property…………………………………………….37
3.2.1.8: Determination of number of colony forming units…………………………...38
3.3.0: Statistical Analysis……………………………………………………………...38
CHAPTER FOUR 39 – 51
4.0: Result and Discussion……………………………………………………………39
4.1: Effect of storage condition and packaging materials on Total Soluble solids……39 – 40 4.2: Effect of storage condition and packaging materials on total titratable acidity…...41
4.3: Effect of storage condition and packaging materials on pH……………………….42
4.4: Effect of storage condition and packaging materials on lycopene…………………43 – 44
4.5: Effect of storage condition and packaging materials on total carotene…………….45 – 46
4.6: Effect of storage condition and packaging materials on moisture content…………47 – 48
4.7: Effect of storage condition and packaging materials on sugar-acid ratio…………..49
x 4.8: Effect of storage condition and packaging materials on colour…………………….50
4.9: Effect of packaging materials on the total number of colony forming units………..51
CHAPTER FIVE 52
5.0: Conclusion and Recommendation………………………………………………...52
5.1: Conclusion………………………………………….....…………………………..52
5.2: Recommendation………………………………………………………………….52
References…………………………………………..…………………………………53 - 58
