1.2 Problem Statement
The fatty acid composition of vegetable oils can vary significantly depending on environmental conditions and geographical location. Although general fatty acid profiles of vegetable oils are well documented, the specific quantities of individual fatty acids may differ across regions, thereby affecting oil quality and nutritional value. There is therefore a need to determine and update the fatty acid composition of vegetable oils produced in the West Nile sub-region.
Additionally, vegetable oils may be contaminated with heavy metals originating from environmental sources such as soil, fertilizers, and pesticides. The use of agrochemicals, including fertilizers and pesticides, contributes to heavy metal accumulation in soils, which can subsequently be absorbed by crops. These metals can accelerate oxidative degradation of fatty acids and negatively impact oil quality and safety.
In the West Nile region, the widespread use of fertilizers such as triple superphosphate and diammonium phosphate, as well as pesticides in commercial agriculture, increases the risk of heavy metal contamination in oilseed crops. Therefore, it is essential to assess the levels of heavy metals, fatty acid composition, and physicochemical properties of oils derived from oil seeds grown in this region.
1.3 General Objective
To analyze the fatty acid composition, heavy metal concentrations, and physicochemical characteristics of selected oil seeds grown in the West Nile sub-region of Uganda.
1.3.1 Specific Objectives
- To determine the physicochemical properties of sunflower (Helianthus annuus), sesame (Sesamum indicum), and peanut (Arachis hypogaea) oils from different locations in the West Nile region.
- To analyze the fatty acid composition of sunflower, sesame, and peanut oils from various locations within the region.
- To determine the concentrations of cadmium (Cd), zinc (Zn), iron (Fe), and lead (Pb) in selected vegetable oils from the West Nile region.
1.4 Scope of the Study
This study focused on analyzing fatty acid composition, heavy metal concentrations (Cd, Pb, Fe, and Zn), and physicochemical properties of selected vegetable oils, namely peanut, sesame, and sunflower oils. The oil samples were obtained from the districts of Arua, Yumbe, Nebbi, and Zombo in the West Nile sub-region. The study was conducted over a period spanning from August 2017 to August 2018.
1.5 Hypotheses
- H₀₁: There is no significant variation in the physicochemical properties of vegetable seed oils produced in the West Nile region.
- H₀₂: There is no significant difference in the fatty acid composition of vegetable oils obtained from seeds grown in different locations within the West Nile sub-region.
- H₀₃: There is no significant heavy metal contamination in vegetable oils produced from seeds grown in the West Nile sub-region.
1.6 Significance of the Study
Vegetable oils are important dietary sources of essential fatty acids. The findings of this study will help consumers make informed comparisons between locally produced and imported vegetable oils in terms of quality and safety.
The study will also provide valuable data to policymakers and regulatory authorities to support the development of standards and regulations governing the production, processing, and consumption of vegetable oils.
Furthermore, the research will contribute to scientific knowledge by providing updated information on fatty acid composition and heavy metal contamination in oils from the West Nile region. This information will be useful for researchers and stakeholders in the agricultural and food sectors.
Finally, the study will enhance understanding of how heavy metals contribute to oil degradation processes such as rancidity and highlight the potential health risks associated with their accumulation in edible oils.
