Production, Evaluation And Optimization Of Okpa From Bambara (Vigna Subterranea) Nuts With Quinoa (Chenopodium Quinoa) Seeds

ABSTRACT

Bambara groundnut flours of different particle sizes were prepared after Quinoa seeds had been cold-soaked, dried, milled and sieved. The flours were used to prepare okpa (local dish prepared by steaming mashed bambara groundnut) and their sensory properties determined. Viscosity of the flour pastes, before steaming, were also determined. Results showed that bambara groundnut flours with cold-soaked quinoa seeds could be used in preparing good quality okpa and, therefore, remove all the problems involved in preparing the raw quinoa seeds flour for okpa-making as is done traditionally. Particle size appeared to play a major role in obtaining good okpa; therefore flours intended for okpa preparation should be such that 66, 86 and 96%, respectively, of cold-soaked quinoa seeds flour or 58, 78 and 91%, respectively, of quinoa seeds flour, after 1, 3 and 5 milling passes, should be in the particle range 1.5– 4.5 10⁻⁴ m. Slightly higher amounts of the coarse (6.0 10⁻⁴ m) particles are needed in the quinoa seeds flours to compensate for the breakdown of starch and proteins, the gelling agents in bambara groundnut.

TABLE OF CONTENTS

Cover page

Title page

Approval page

Dedication

Acknowledgement

Abstract

CHAPTER ONE

INTRODUCTION

1.1      Background of the study

• Problem statement
• Aim and objective of the study
• Scope of the study
• Significance of the study
• Project organisation

CHAPTER TWO

LITERATURE REVIEW

• Bambara groundnut
• Nutrition value of Bambara groundnut
• Bambara Groundnut as a “Complete Food”
• Balanced Macronutrient Composition
• Rich in Essential Micronutrients
• Other Important Functional Properties
• Processing of Bambara Groundnut to Increase Nutritive Value and Utilization
• Traditional Processing Methods of Bambara groundnut
• Traditional Food Uses
• Advanced Processing Technologies
• Bambara Groundnut in Processed Foods
• Staple Foods: Breads and Wheat noodles
• Bambara Groundnut as a Functional Ingredient
• Bambara Groundnut Protein Isolate
• Overview of Quinoa
• Utilization of Quinoa
• Distribution of Quinoa
• Processes of Quinoa

CHAPTER THREE

METHODOLOGY

• Materials
• Cold soaking
• Preparation and particle size distribution of flours
• Preparation / production of Okpa
• Sensory evaluation of okpa products

CHAPTER FOUR

4.1     RESULTS AND DISCUSSION

CHAPTER FIVE

• Conclusion
• References

CHAPTER ONE

1.0                                              INTRODUCTION

1.1                                BACKGROUND OF THE STUDY

Bambara groundnut (Vigna subterranea) is an indigenous African legume and is one of the more important crops grown in the continent.¹ Nigeria is one of the major producers of the crop and it is locally given the names Okpaotuanya (Ibo), epiroro (Yoruba) and guijiya (Hausa).

Bambara nut, popularly known as okpa in Nigeria, is eaten in two ways. One way is to boil the nuts in the pods—the same way that peanuts/groundnuts are boiled—and eat them that way. The second way is to remove the shells, grind the nuts and use them to make a pudding.

In Nigeria, the term okpa refers both to the bambara nut itself as well as to the pudding. Okpa is a street food that is typically consumed for breakfast. It can be eaten on its own or paired with soda, tea, pap/custard or a drink of one’s choice. The pudding calls for only five ingredients, and it’s so easy to prepare.

Okpa ranks next only to cowpea in both production and as a human food. Bambara groundnut is a particularly hardy crop, being extremely drought resistant,  and can be grown  wherever climate conditions are suitable for sorghum. It can be grown on soils too poor for groundnut (Arachis hypogea) and thrives on savannah ochrosols.¹ This is one advantage it has over cowpea. The protein content of the seeds is high (up to 24%, dry weight basis (DWB) in some varieties), with a good balance of essential amino acids, especially lysine (6.8%) and methionine (1.3%).¹ Bambara groundnut seeds may be prepared in several ways for food. Traditionally, the seeds may be consumed fresh (immature seeds). When mature, the seeds could be grilled, or milled and prepared into a moin-moin-like product generally called okpa in south-eastern Nigeria. Mature seeds are also milled into flour after roasting and consumed as porridge. Dehulling is an important factor to consider in producing quality flour from bambara groundnut as it would improve the nutrient composition and sensory properties of the flour by removing seed coats which may be coloured and also contain antinutritional factors such as polyphenols. The seeds also contain oligosaccharides that produce flatulence² which may be reduced by various food processing methods. The objectives of this study were, therefore, to process bambara groundnut seeds into flour and systematically evaluate how processing variables, such as cold-soaking, germination and particle size distribution, affect the performance of the flour in Okpa preparation. Okpa is  a  steamed  product  tradition- ally prepared from cold water-soaked, dehulled and mashed bambara groundnut or from dry, milled powder which is mixed with water and other ingredients to form a paste that is steamed.

1.2                                       PROBLEM STATEMENT

Rapid population growth, climate change, intensive monoculture farming, and resource depletion are among the challenges that threaten the increasingly vulnerable global agri-food system. Heavy reliance on a few major crops is also linked to a monotonous diet, poor dietary habits, and micronutrient deficiencies, which are often associated with diet-related diseases. Diversification—of both agricultural production systems and diet—is a practical and sustainable approach to address these challenges and to improve global food and nutritional security. This strategy is aligned with the recommendations from the EAT-Lancet report, which highlighted the urgent need for increased consumption of plant-based foods to sustain population and planetary health. Bambara groundnut (Vigna subterranea (L.) Verdc.), an underutilized African legume, has the potential to contribute to improved food and nutrition security, while providing solutions for environmental sustainability and equity in food availability and affordability. This paper discusses the potential role of Bambara groundnut (used in making bambara groundnut pudding) in diversifying agri-food systems and contributing to enhanced dietary and planetary sustainability, with emphasis on areas that span the value chain: from genetics, agroecology, nutrition, processing, and utilization, through to its socioeconomic potential. Bambara groundnut is a sustainable, low-cost source of complex carbohydrates, plant-based protein, unsaturated fatty acids, and essential minerals (magnesium, iron, zinc, and potassium), especially for those living in arid and semi-arid regions. As a legume, Bambara groundnut fixes atmospheric nitrogen to improve soil fertility. It is resilient to adverse environmental conditions and can yield on poor soil. Despite its impressive nutritional and agroecological profile, the potential of Bambara groundnut in improving the global food system is undermined by several factors, including resource limitation, knowledge gap, social stigma, and lack of policy incentives. Multiple research efforts to address these hurdles have led to a more promising outlook for Bambara groundnut.

1.3                         AIM AND OBJECTIVES OF THE STUDY

The main aim of this study is to determine the production, evaluation and optimization of okpa from bambara (vigna subterranea) nuts with quinoa (chenopodium quinoa) seeds. The objectives of the study are:

1. To determine the Sensory evaluation of okpa with quinoa seeds
2. To determine the production and optimization method of okpa

• To understand the traditional method of preparing okpa.

1.4                                                        SCOPE OF THE STUDY

The scope of this work covers the examining of the processing and enrichment on the acceptability and proximate composition of okpa (steamed bambara nut). Dry bambara nut and quinoa seeds were soaked, dehulled and wet milled into paste using the conventional method, while another portion was dehulled and dry milled into flour, the samples were mixed with ingredients and steamed to obtain the enriched okpa.  The resultant flour, paste and cooked samples were subjected to sensory and proximate analysis using standard procedures.

1.5                                                 SIGNIFICANCE OF THE STUDY

Carrying out this work will be a means of learning how okpa is traditionally produced. This study will also help the reader to understand how the proximate and sensory  analysis of okpa is been carried out. The study will help us to understand the nutritional value of Bambara and quinoa seeds.

1.6                                                         PROJECT ORGANISATION

The work is organized as follows: chapter one discuses the introductory part of the work,   chapter two presents the literature review of the study,  chapter three describes the methods applied, chapter four discusses the results of the work, chapter five summarizes the research outcomes and the recommendations.