CHAPTER ONE

1.0       INTRODUCTION

1.1       BACKGROUND OF THE STUDY

Watermelon (Citrallus lanatus) is an important horticultural crop, mostly known for its sweet juicy fruit (Munisse et al., 2011). It belongs to the genus Citrullus, which has four species (C. lanatus, C. ecirrhosus, C. colocynthis, and C. rehmi) (Shimotsuma, 1963). A study by Dane and Liu (2007), using chloroplast DNA to infer biogeographic and evolutionary relationship, origin, and domestication suggests that cultivated and wild watermelon have diverged independently from a common ancestor, most possibly C. ecirrhosus from Namibia. It is an important but underutilized crop. When used fresh or processed into juice, it generates much waste in the form of rind and seeds (Asghar et al., 2012). Although the seeds are considered waste, they have been shown to be highly nutritive and contain large amounts of proteins and many beneficial minerals (Yadav et al., 2011). Depending on the variety, virtually all parts of the watermelon plant can be used for food, including leaves, shoots, roots, flowers, seeds, and immature and mature fruits (Jacks et al., 1972).

Indigenous watermelon seeds are drought tolerant and produce different types of fruits. Morphologically, they differ in color and shape. There are those that are green, striped or grey. These can in turn have red or white flesh and there are those that produce more seeds than others. Many poor households in South Africa use watermelon seeds as a relish taken roasted with stiff porridge. The composition of the seeds is not known and is likely to be different among different landraces. Some may have high protein and low lipid content and vice versa. There might be those whose lipid content and composition is comparable to those of the sunflower or with the protein content being comparable to that of the soybean. Identification of such landraces or varieties can lead to them being produced sustainably in dry areas.

1.2       STATEMENT OF RESEARCH PROBLEM

 Although watermelon fruit (Citrallus lanatus) and its varieties ( which include Crimson sweet, Mickylee, Stars and Stripes)  and their seed is widely known, the current scientific knowledge on the nutritional value(proximate composition and lipid profile)  and  importance of its fruit is studied. Watermelon fruit is dominant tropical fruit consumed by many. When used fresh or processed into juice, it generates much waste in the form of rind and seeds (Asghar et al., 2012). Although the seeds are considered waste, they have been shown to be highly nutritive and contain large amounts of proteins and many beneficial minerals (Yadav et al., 2011).

1.3       JUSTIFICATION

v  Watermelon fruit was eaten as a sweet and used to make ice cream and refreshing drinks.

v  Survey confirmed that a watermelon fruit seed was consumed by people of all ages including the old, young, healthy and pregnant women.

v  Watermelon fruit is consumed worldwide and used as an ingredient in processed product such as fruit salad, juice blend etc.

v  Watermelon seed contains oil which could be of domestic and industrial application.

1.4       OUTCOMES OF THE RESEARCH

The outcomes of this project is to give an indication of how the watermelon seeds can be more beneficial to society as opposed to being regarded as waste, and also to highlight the potential of the use of the seeds and the seed-oil commercially. The results of the study will allow subsistence farmers the opportunity to breed their landraces in a way that would yield them more products that they may desire. They can also have insight on which variety of watermelon to grow.

1.5       AIM

The study aimed to evaluate the proximate composition of watermelon seed in addition to extraction and evaluation of physiochemical properties of the watermelon seed oil.

1.6       OBJECTIVES

The objectives of this study are:

Ø  To determine the proximate composition of the watermelon seed.

Ø  To extract the seed oil using soxhlet apparatus.

Ø  To determine the physiochemical properties of the watermelon seed oil.

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