1.1 Introduction
Watermelon (Citrullus lanatus) is a flowering plant species of the Cucurbitaceae family and the name of its edible fruit. A scrambling and trailing vine-like plant, it is a highly cultivated fruit worldwide, with more than 1,000 varieties. The watermelon seeds are known to have economic benefits especially in countries where cultivation is on the increase. They are used to prepare snacks, milled into flour and used for sauces. Oil from the seeds are used in cooking and incorporated into the production of cosmetics (Jensen et al., 2011).
As a prelude to other parts of this study, this chapter will discuss the background upon which this study was initiated, the statement of problems that led to this study, the Aim and Objectives of the study. Others are Significance of the study, Scope of work, Limitation of the study and Definition of technical terms.
1.2 Background of Study
Diets rich in phytochemicals such as carotenoids and phenolic compounds have been associated with a reduced risk of certain types of cancer, cataracts, inflammation, cardiovascular, muscular degeneration and neurodegenerative diseases (Bueno, et al., 2012; Sergent, et al., 2010; Snyder, et al., 2011; Tanaka et al., 2012). Tropical fruits consumption is increasing on domestic and international scale due to growing recognition of their nutritional and therapeutic values (Alves et al., 2008).
Phytochemicals, the biologically active and naturally-occurring compounds in plants provide health benefits for humans. They contribute to plants colour and flavor, and are found in different parts of the plants such as root, stem, leaves, fruits and seeds. They have biological properties such as antioxidant activity, antimicrobial effect, modulation of detoxifying enzymes, stimulation of the immune system, and general modulation of hormonal activity. As a result of these properties, researchers are interested in their health benefits. The identification and quantification of phytochemicals in pulps and byproducts of tropical fruits are of utmost importance in order to substantiate their potential health benefits in human nutrition. Fruits occupy a part of daily diet of the rich and rarely the poor and there are many parts of a fruit that are not considered edible, and so are usually thrown away.
One such fruit is Citrullus lanatus, which is taken by all but the seeds, are thrown away and generally not included in regular diet. The juice or pulp of Citrullus lanatus is considered as the edible portion but rind and seeds are discarded as major solid wastes (Bawa and Bains, 1977). The fruit has numerous small black seeds embedded in the middle of the flesh, while the embryo completely fills the seed. The seeds have sweet and nutritious kernels. Citrullus lanatus is of the cucurbitaceae family and several studies have shown that seeds of the cucurbitaceae are potential sources of nutrients such as protein, minerals and lipids as well as ingredients for native medicine.
Watermelon is grown in favorable climates from tropical to temperate regions worldwide for its large edible fruit, which is a berry with a hard rind and no internal divisions, and is botanically called a pepo. The sweet, juicy flesh is usually deep red to pink, with many black seeds, although seedless varieties exist. The fruit can be eaten raw or pickled, and the rind is edible after cooking. It may also be consumed as a juice or an ingredient in mixed beverages (Wikipedia, 2021).
The plant is related to the cantaloupe, squash and pumpkin and other plants that grow on vines (on the ground). It is high in fibre, citrulline and arginine (Collins et al., 2007; Oyeleke et al., 2012). Citrullus lanatus seeds are highly nutritional; they are rich sources of protein, B-group of vitamins, minerals (such as magnesium, potassium, phosphorous, sodium, iron, zinc, manganese and copper), fat, as well as phytochemicals (Braide, et al., 2012).
Therefore, in Nigeria where the research was carried out, the activities that was conducted is to know the Phytochemical and Mineral Composition, Proximate Analysis and In Vitro Antioxidant Activities of Watermelon (Citrullus Lanatus) Seeds.
1.3 Statement of Problems
Investigation revealed the problems associated with the phytochemical and mineral composition, proximate analysis and in vitro antioxidant activities of watermelon (citrullus lanatus) seeds;
- Lack proper estimation of watermelon phytochemical and mineral composition,
- Inadequate information relating to the in vitro antioxidant activities of watermelon seeds,
- Lack of proper and precise information relating to the proximate analysis of watermelon seeds.
1.4 Aim and Objectives of Study
The aim of the study is to determine the Phytochemical and Mineral Composition, Proximate Analysis and In Vitro Antioxidant Activities of Watermelon (Citrullus Lanatus) Seeds. In achieving this aim, the following specific objectives were laid out as follows:
- To estimate the watermelon phytochemical and mineral composition,
- To provide information relating to the proximate analysis of watermelon seeds,
- Provision of information relating to the in vitro antioxidant activities of watermelon seeds.
1.5 Significance of Study
The findings of this research will help to estimate the watermelon phytochemical and mineral composition, to provide information in vitro antioxidant activities of watermelon seeds, and proximate analysis of watermelon seeds.
This study will be of immense benefit to academic students and other researchers who intend to know more on this study and can also be used by non-researchers to build more on their research work. This study contributes to knowledge and could serve as a guide for other study.
1.6 Scope of Study
The scope of the research is focused on the In Vitro Antioxidant Activities of Watermelon (Citrullus Lanatus) Seeds.
1.7 Limitations of the Study
During the course of this study, many things militated against its completion, some of which are:
- Time Constraint: The time frame given to accomplish this project was very short due to school academic calendar and it was carried out under pressure which made the researcher not to implement some necessary features.
- Research material: availability of research material is a major setback to the scope of the study.
- Frequent power failure: This made the researcher append more money on fuel to ensure sustainable power.
- Financial Constraint: Insufficient fund tends to impede the efficiency of the researcher in sourcing for the relevant materials, literature or information and in the process of data collection.
1.8 Definition of Terms
Watermelon: A watermelon is a large berry whose swollen roundness and vibrant red flesh connote fertility and sexuality.
Seeds: the unit of reproduction of a flowering plant, capable of developing into another such plant.
Phytochemical: Phytochemical is a chemical compound produced by plants, generally to help them resist fungi, bacteria and plant virus infections, and also consumption by insects and other animals.
Mineral: A mineral is a naturally occurring inorganic element or compound having an orderly internal structure and characteristic chemical composition, crystal form, and physical properties.
Composition: composition is the act of putting something together, or the combination of elements or qualities.
Mineral Composition: The composition of a mineral can be expressed as a chemical formula, which simply gives the proportions of the different elements and groups of elements in the mineral.
Proximate: Proximate is used in the analysis of biological materials as a decomposition of a human-consumable good into its major constituents.
