Determine the Mass Transfer Characteristic of Thermal Drying and Osmotic Dehydration of Pumpkin and Bitter Leaf

Determine the Mass Transfer Characteristic of Thermal Drying and Osmotic Dehydration of Pumpkin and Bitter Leaf

ABSTRACT

The experiment was carried out and three osmotic solutions were prepared, “hypertonic solution 60% concentrated, hypotonic solution 40% concentrated and isotonic solution 50% concentrated” and oven drying was also carried in the course of the experiment, the effect of sodium chloride (osmotic agent) concentration, temperature and immersion time on overall mass transfer coefficient, effective diffusivity, drying rate weight loss and shrinkage ratio on oven drying and osmotic dehydration of Pumpkin and bitter leaf.

Results showed that both pumpkin and bitter leaf had a highest mass transfer coefficient in oven drying at highest temperature of 80^oc, for pumpkin leaf 0.149(m/min), bitter leaf was 0.149(m/min), the results were also obtain for osmotic dehydration at 80Oc at highest concentration (Hypertonic solution) had the highest mass transfer coefficient, for pumpkin leaf was 0.015(m/min) for bitter leaf was obtained to 0.032(m/min).

For osmotic dehydration, both samples weight loss percent (WL%) for hypertonic solution at 800C for 90mins had the highest weight loss percent, but the shrinkage ratio decrease with increase in time.

The mass transfer during oven drying of pumpkin and bitter leaf was described using Fickian equation of diffusion with drying taking place in the falling rate period, the effective moisture diffusivity value showed temperature dependence on both samples.

Effective diffusivity values were also determined for oven drying at different temperature, and the values increases as the temperature increases, for pumpkin and bitter leaf at 600C, 700C and 800C, the effective diffusivities were 1.0E-09, 1.87106E-09 and 2.1843E-09m2/min and 8.52966E-10, 1.00015E-9 and 2.45308E-08m2/min.

Table of Contents

ABSTRACT           1

CHAPTER ONE   3

INTRODUCTION 3

1.1          BACKGROUND OF THE STUDY     3

1.2          STATEMENT OF THE PROBLEM   6

1.3          OBJECTIVES OF THE STUDY           7

1.4          RESEARCH QUESTIONS  7

1.5          RESEARCH HYPOTHESES 8

1.6          SIGNIFICANCE OF THE STUDY      8

1.7          SCOPE/LIMITATION OF THE STUDY           9

1.8          PLAN OF THE STUDY       9

CHAPTER TWO  11

LITERATURE REVIEW       11

2.1          INTRODUCTION 11

2.2 CONCEPTUAL REVIEW            11

2.3          THEORETICAL FRAMEWORK        18

2.4 EMPIRICAL REVIEW  21

CHAPTER THREE                24

RESEARCH METHODOLOGY         24

RESEARCH DESIGN          24

POPULATION OF THE STUDY        24

SAMPLE AND SAMPLING TECHNIQUE      24

DATA COLLECTION           25

RESEARCH INSTRUMENT (QUESTIONNAIRE)         25

VALIDITY AND RELIABILITY OF RESEARCH INSTRUMENT   25

ADMINISTRATION OF QUESTIONNAIRE  26

STATISTICAL TOOLS OF DATA ANALYSIS  26

CHAPTER FOUR:               28

4.0 DATA PRESENTATION, DATA ANALYSIS AND INTERPRETATION              28

4.1 INTRODUCTION        28

4.2 DATA PRESENTATION AND ANALYSIS               28

TABLE BASED ON RESEARCH QUESTION 32

4.3 TEST OF HYPOTHESIS               40

CHAPTER FIVE   43

SUMMARY, CONCLUSION AND RECOMMENDATIONS      43

5.1          INTRODUCTION 43

5.2          SUMMARY          43

5.3          CONCLUSION    44

5.4          RECOMMENDATIONS    46