Nutritional Potential of Underutilized Edible Plants

104 Pages·2017·2.51 MB·English

by  Habtamu Seyoum Aragaw

Agricultural Sciences and Resources Management in the Tropics and Sub-tropics
Zentrum für Entwicklungsforschung - Center for Development Research

Nutritional potential of underutilized edible plants in agroforestry systems of
Yayu, Southwestern Ethiopia

Thesis
In partial fulfilment of
the requirements for the
academic degree of

Master of Science
of the
Faculty of Agriculture
Rheinische Friedrich-Wilhelms-Universität zu Bonn

Submitted on July 11, 2017
by
Habtamu Seyoum Aragaw
Ethiopia

Nutritional potential of underutilized edible plants in agroforestry systems of
Yayu, Southwestern Ethiopia

Thesis
In partial fulfilment of
the requirements for the
academic degree of

Master of Science

of the
Faculty of Agriculture
Rheinische Friedrich-Wilhelms-Universität zu Bonn

Submitted on July 11, 2017
by
Habtamu Seyoum Aragaw
Ethiopia
Nutritional Potential of Underutilized Edible Plants Habtamu S. Aragaw

Supervisors and chair person
1. Dr Manfred Denich (Chair)
2. Prof. Dr. Mathias Becker
3. Dr. Daniel Callo-Concha

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Nutritional Potential of Underutilized Edible Plants Habtamu S. Aragaw

Declaration

I declare that the thesis hereby submitted by me for the Degree Master Sciences (MSc.) to Bonn
University is my own independent work and has not previously been submitted by me or anybody
else at another university. The materials obtained from other sources have been properly
acknowledged in this thesis.

MSc Candidate –––––––––––––––––––––––––
Habtamu Seyoum Aragaw

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Nutritional Potential of Underutilized Edible Plants Habtamu S. Aragaw

Acknowledgement
I use this opportunity to express my gratitude to everyone who supported me during the course of
my studies. My supervisors Dr. Daniel Callo-Concha and Prof. Dr. Nohr Donatus. I am very
thankful for their aspiring guidance, invaluable advice and constructive comments of this thesis
research. My sincere thanks to Prof. Dr. Mathias Becker for his last-minute support. I want to
thank Dr. Manfred Denich for his willingness to chair my defense.
My studies were sponsored by the German Academic Exchange Service (DAAD). I am extremely
grateful for the support and the precious opportunity to study in one of the best university in
Germany.
My sincerely gratitude to the ARTS program, in particularly to Prof. Dr. Mathias Becker who
selected me to study Master in Agriculture Sciences and Resource Management in the Tropics and
Sub-tropics, a multi-specialized program in which I have learnt basic and applied sciences from
gene to biodiversity, from crop production to system productivity, from agriculture to ecological
function and climate change, from plant DNA to species diversity and many more. I will always
be honored being part of this multi-disciplinary program. I also thank Mrs Susanne Hermes for
her active coordination, encouragement, advice and interaction with all of us.
I would also extend my gratitude to the BiomassWeb project for funding my field research. My
sincere gratitude also goes to the BiomassWeb project partner organizations, including Centre for
Development Research (ZEF), who hosted and provided me the necessary logistics especially in
the last year of my studies; Environment and Coffee Forest Forum (ECFF), Ethiopia, who
supported me to reach to the Yayu Forest resources and provided me letters of support during my
contact with different institutions such as National Herbarium of Ethiopia, Addis Ababa University
and Bureau of Agriculture, Illu Aba bora Zone, Ethiopia.
My sincere thanks to my employer, Ethiopian Institute of Argiculture Research, jimma agriculture
research Centre, for providing me logistics during my field research. My sincere thanks also go to
Post Harvest Management and Animal Nutrition departments, Jimma University, Ethiopia for
allowing me to use their laboratory in order to perform food nutrient analysis. Similarly, I would
like to thank the laboratory technicians in plant nutrition department, Bonn Univeristy, especially
Mrs. Angelika Veits for her support and supervision throughout my laboratory analysis. Finally,
my sincere thanks go to Mrs Margaret Jend who supported me in editing the manuscript.
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Nutritional Potential of Underutilized Edible Plants Habtamu S. Aragaw

Dedication
This MSc. Degree is dedicated to my wife Meseret Haile Woldesemyat, who played a crucial
role towards my success.

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Nutritional Potential of Underutilized Edible Plants Habtamu S. Aragaw

List of Abbreviations
AAS Atomic Absorption Spectroscopy
AES Atomic Emission Spectroscopy
ANOVA Analysis of variance
AOAC Association of Official Analytical Chemist
BMBF German Federal Ministry of Education (Bündermministrium für Bildung und Forshung)
German Federal Ministry for Economic Cooperation and Devlopment
BMZ
(Bundesministerium für wirtschaftliche Zusammenarbeit und Entwicklung)
CSA Central Statistics Agency
CV Coefficient of variation
DHS Demographic Health Survey
ECFF Environment and Coffee Forest Forum
EHNRI Ethiopian Health and Nutrition Research Institute
EP Edible portion
FAO Food and Agricultural Organization
IFPRI International Food Policy Research Institute
INFOOD International Network of Food Data Systems
IPGRI International Plant Genetic Resources Institute
LSD Least Significant Differences
MoH Ministry of Health, Ethiopia
ND Not determined
UNESCO United Nations Educational, Scientific and Cultural Organization
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Nutritional Potential of Underutilized Edible Plants Habtamu S. Aragaw

UNICEF United Nations International Children’s Emergency Fund
USDA-NRCS United States Department of Agriculture- Natural Resources Conservation Service
USDA-FCD United States Department of Agriculture- Food Composition Database
UV-Vis Ultraviolet-Visible Spectrophotometry
WHO World Health Organization

List of Tables
Table 1. Families, genus and species and life form of edible plants identified by household
survey in agroforests of Yayu ....................................................................................................... 26
Table 2. Plant families with highest number of edible species .................................................... 27
Table 3. Selected underutilized edible plants identified from Yayu area, southwest Ethiopia .... 31
Table 4. Proximate food composition of 12 underutilized edible plant species (per 100 g dry
edible portion) ............................................................................................................................... 34
Table 5. Mineral composition of 12 underutilized edible plant species (mg/100 g dry EP) ........ 36
Table 6. Vitamins and antinutritional factors in 12 underutilized edible plant species (per 100 g
fresh edible portion) ...................................................................................................................... 37
Table 7. Vitamins and antinutritional factors content of 12 underutilized edible plant species (per
100 g fresh edible portion) ............................................................................................................ 46

List of Figures
Figure 1. Map of the study area. .................................................................................................. 10
Figure 2. Schematic presentation of research design. .................................................................. 12
Figure 3. Growth cycle of edible species by food category in Yayu ........................................... 28
Figure 4. Source of edible plant species and their edible part consumed in Yayu ...................... 29
Figure 5. Proportion of edible plant species consumed through various methods of preparation
and the current level its use. .......................................................................................................... 30
Figure 6. Wild fleshy fruit of Rubus apetalus .............................................................................. 62
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Nutritional Potential of Underutilized Edible Plants Habtamu S. Aragaw

Figure 7. Wild edible yam (Dioscorea prehensilis) tuber ........................................................... 63
Figure 8. Unripe wild edible fruit of Tristemma mauritianum. ................................................... 64
Figure 9. Wild fleshy fruit of Carissa spinarum ........................................................................... 67
Figure 10. Tuber of Dioscorea alata, raw (left) and cooked (right) ............................................. 68
Figure 11. Solanum nigrum ......................................................................................................... 70
Figure 12. Purslane (Portulaca oleracea) ..................................................................................... 72
Figure 13. Leaves and young shoots of Hypolepis sparsisora ..................................................... 74
Figure 14. Wild fleshy fruit of Syzygium guineense ................................................................... 75

Table of Contents
List of Abbreviations .................................................................................................................... v
List of Tables ................................................................................................................................ vi
List of Figures ............................................................................................................................... vi
Table of Contents ........................................................................................................................ vii
Abstract ......................................................................................................................................... ix
1. Introduction ....................................................................................................................... 1
1.1. Objectives ........................................................................................................................... 3
2. Literature review .............................................................................................................. 4
2.1. Nutrition situation in Ethiopia ............................................................................................ 4
2.2. Link between agriculture and nutrition in Ethiopia ............................................................ 6
2.3. The role of underutilized species for food and nutrition security in Ethiopia .................... 7
3. Materials and methods ................................................................................................... 10
3.1. Study area.......................................................................................................................... 10
3.2. Sampling and data collection ............................................................................................ 11
3.2.1. Research design ................................................................................................................ 11
3.2.2. Sampling and data collection ............................................................................................ 12
3.2.3. Species proximate food composition and nutrient content ............................................... 14
3.3. Statistical analysis ............................................................................................................. 24
4. Results .............................................................................................................................. 25
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