1.1 Introduction
Vegetables are considered very important part of human diet not only in developing countries like Nigeria but all over the world. Nigeria, which is the most densely populated country in African continent, is still struggling to achieve self-sufficiency to feed its over 200 million people. According to reports, vegetables consumption is influenced by gender, age income education and family origin ad as well as health status (Wadle et al., 2000, Giskes et al., 2002).
The amount of nutrient constituent in the more commonly used leafy vegetables species in Nigeria have been studied to some extent (Kola, 2004), the lesser known region and local species remain virtually neglected. Lack of information on the specific nutrients and phytochemicals in a large number of the native vegetable species with which Nigeria is richly endowed is partly responsible for their under exploitation especially in areas beyond the traditional location where they are found and consumed.
Pharmacological importance of leafy vegetables deals with the phytochemical component of a vegetable which determines its colour and medicinal effect (Phytochemical Aspect) and the nutritional importance of leafy vegetables deals with the nutrients present in the leafy vegetables consumed such as protein content, carbohydrate content, vitamin content etc.
Vegetables are eaten in a variety of ways as part of the main meal or as snacks. The nutrient content of leafy vegetables varies considerably, though generally they contain protein or fat and varies in the proportion of vitamin they contain such as vitamin A, vitamin K, and vitamin B, minerals and carbohydrate. Leafy vegetables are not major sources of carbohydrate compared with starchy food.
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, Research questions, Limitation of the study and Definition of terms.
1.2 Background of Study
Recently, knowledge of post-harvest handling such as improve storage, packaging and handling techniques are practically non-existents with perishable crops and even if they existed, they were not easily accessible by the indigenes in the producing areas, so this allows for considerable losses of produce. Since vegetables can change hands so many times in the post-harvest sector, a high level of management is necessary to ensure that quality is maintained. Each time someone fails to be conscientious in carrying out his or her assigned responsibility, quality is irreversibly sacrificed. Those involved in the handling of vegetable products are the producers, middlemen, marketing specialist and consumers. Appropriate post-harvest handling practices are important to minimize post-harvest losses and to maintain the quality of fruits and vegetables (Aujla et al., 2011).
Estimate of production losses in developing countries are usually very hard to come by. Post harvest losses in vegetable in African countries have been estimated to about 50% of the total production (FAO, 2008). This implies that half of the total production are lost during storage handling and transportation of their produce. Therefore, minimizing these losses to a barest minimum between harvest and consumption, of already produced food is more sustainable than increasing production (Kader and Rolle, 2004).
Farmers are forced to sell their products at give away prices due to absence of adequate storage and marketing facilities. In some cases, the expected income goes to the dustbin. Post harvest losses are caused by mechanical injuries, inadequate storage, unsuitable handling, faulty system of transport and delayed transportation in retail market (CEAGESP, 2002). Green vegetables refer to all leafy vegetables predominantly green in colour which can be eaten boiled or in soups. They have achieved tremendous popularity over the last century among local traders. Besides being tasty, they (green vegetables) promote healthy nutritional balance as they are good sources of vitamin A and C, are low in calories and fats, high in protein per calorie, dietary, fibre, iron and calcium. They have a very short shell life of about 1-2 days. They have high economic value and high consequence of post harvest losses. The socio-economic factors tend to influence households’ vegetable crop production, marketing and are central in decision making with the main objective of meeting their subsistence needs and incomes.
Olubunmi et al. (2017) in their studies of assessment of dry season garden egg production among small-scale holder farmers in Edu Local Government Area of Kwara State, Nigeria reported that 100% of the farmers were male, 28.40% had age range of between 26- 36 years, 80.00% were married, 91.70% had Islam as their religion, 31.75 had quaranic education, 47.70% had farming experience between 6-10 years .Similarly, 46.70% had household size of between 6-10 persons, 65% had farm size less than 0.51 ha and 76.60% had farming as their major occupation.
Alao (2000) observed that practically all leafy vegetables such as amaranthus, cabbage, and lettuce among others grown are consumed in Nigeria and production is seasonal resulting in glut during the rainy season and scarcity at off sea- sons. Due to their soft texture, they are easily bruised or wounded as a result of harvesting, and other post-harvest handling operations such as packaging, transportation and storage. In Northern part of Nigeria where production of leafy veg- etables is all year round among those that farm using irrigation system. Despite producing adequate quantities of leafy vegetables, they become inadequate on account of losses and wastages in the field as well as along the value chain before reaching the final consumers.
Therefore, in Nigeria where the research was carried out, the activities that was conducted is to know the Nutritional and Pharmacological Importance in Common Vegetables.
1.3 Statement of Problems
Investigation revealed that the importance of leafy vegetables in improving the nutritional and economy needs of rural farmers cannot be underestimated. Leafy vegetables are essential part of human diets, but they are perishable by nature. Losses between farms and consumers are common in Nigeria where there is inadequate knowledge; skills, technologies, techniques, and facilities for produce handling and processing. These losses of leafy vegetables and economic opportunities have contributed to poverty, unemployment and malnutrition.
The varied agro-climatic conditions prevailing in Nigeria are conducive for the cultivation of leafy vegetables in different stages round the year. Nigeria is a country that is rich in the supply of agricultural products including leafy vegetables but post-harvest losses continue to reduce its impact on the socio-economic life of the rural farmers and to some extent Nigerians thereby creating food insecurity as being witness presently. In Northern part of Nigeria, despite producing adequate quantities of leafy vegetables, they become inadequate on account of losses in the field as well as in storage.
1.4 Aim and Objectives of Study
The aim of the study is to examine the Nutritional and Pharmacological Importance in Common Vegetables in Nigeria. In achieving this aim, the following specific objectives were laid out as follows:
- To examine the nutritional importance of common vegetables; and
- To identify the pharmacological importance of common vegetables.
1.5 Research Questions
The study came up with research questions so as to be able to ascertain the above stated objectives. The specific research questions for the study are stated below as follows:
- What is the nutritional importance of common vegetables?
- What is the pharmacological importance of common vegetables?
1.6 Research Hypothesis
In order to pursue the objective of this study, the following generalized statements have been designed to guide and aids in obtaining the result for the experiment to be conducted. For this work, the null hypothesis will be represented with H0 while the alternative hypothesis will be represented with hypothesis H1.
Hypothesis One
- H0: There is no relationship between nutritional and pharmacological importance development and the use of common vegetables
- H1: There is a relationship between nutritional and pharmacological importance development and the use of common vegetables
1.7 Significance of Study
This study will be of immense benefit to 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.
1.8 Scope of Study
The scope of the research is focused on Reviewing the Nutritional and Pharmacological Importance in Common Vegetables in Nigeria.
1.9 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 (internet, questionnaire and interview).
1.10 Definition of Terms
Nutrition:
Nutrition is the biochemical and physiological process by which an organism uses food to support its life.
Analysis:
It is the process of breaking down a something into its parts to learn what they do and how they relate to one another.
Value:
Values are basic and fundamental beliefs that guide or motivate attitudes or actions. They help us to determine what is important to us.
