1.0 Introduction
1.1 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.
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).
The 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).
1.2 Statement of Problems
The study reveals the following 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.
1.3 Objectives of Study
The aim of this study was to determine the phytochemicals and minerals present in the seed of Watermelon (Citrullus Lanatus). Therefore, the objectives of this research were:
- To estimate the watermelon phytochemical and mineral composition,
- Provision of information relating to the in vitro antioxidant activities of watermelon seeds,
- To provide information relating to the proximate analysis of watermelon seeds.
1.4 Significance of the Study
This research work when completed and implemented it 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. Besides, the study will serve as reference material for subsequent researcher in the field or related topics.
1.5 Scope of Study
The study focuses on the phytochemical and mineral composition, proximate analysis and in vitro antioxidant activities of watermelon (citrullus lanatus) seeds.
1.6 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.
- Establishment Policies: Establishment policies posed a serious limitation as most staffs are not ready to release information needed for this project work. There were lots of information needed from the staffs of this institution to enhance the study which took them time to release or they did not release at all for security purposes, hence the scope was reduced.
1.7 Definition of Technical Terms
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.
Analysis: a detailed examination of anything complex in order to understand its nature or to determine its essential features
Proximate Analysis: Proximate analysis refers to the quantitative analysis of macromolecules in food.
In Vitro: In vitro Describing biological processes that are made to occur outside the living body, in laboratory apparatus (literally 'in glass', i.e. in a test tube).
Antioxidants: Antioxidants are substances that may protect your cells against free radicals, which may play a role in heart disease, cancer and other diseases.
Activities: a thermodynamic quantity representing the effective concentration of a particular component in a solution or other system, equal to its concentration multiplied by an activity coefficient.
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.
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