Browsing by Author "Caku, Jimmy"

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    Comparative analysis of oil extraction rates and nutritional profiles of indigenous and introduced hybrid oil palm varieties in selected districts in Uganda
    (Muni University, 2025-10-06) Caku, Jimmy
    Oil palm (Elaeis guineensis Jacq. L.) is the world’s leading source of plant-based oil, but Uganda depends on imported hybrid varieties because it lacks a domestic breeding program. Important indicators of possible breeding lines for initiating an oil palm breeding program are the oil extraction rate, mass of fat recovery, and nutritional characteristics. A total of 75 ripe oil palm fruit bunches were collected from Bundibugyo, Kanungu, and Kalangala districts. Ripe bunches were procured directly from farmers using the snowball sampling technique to identify oil palm growers in Bundibugyo and Kanungu districts. In Kalangala district, sampling was conducted in three designated blocks with guidance from extension officers of the Kalangala Oil Palm Growers Trust. Following mesocarp drying, oil extraction was performed using a screw press, and both the oil extraction rate and the mass of fat recovered were subsequently measured. The nutritional composition of the oil samples was assessed through multiple analyses. Carbohydrate content was quantified using the Anthrone method, while fatty acid profiles were determined via High-Performance Liquid Chromatography coupled with UV detection. Beta-carotene concentration was measured using a spectrophotometer, and β-carotene content was quantified by recording absorbance at 449 nm. Independent Samples t-test to determine whether there were statistically significant differences in mean values of the oil extraction rate, mass of fat recovery and other nutritional properties between the indigenous genotypes and introduced hybrid varieties. One-way ANOVA was used to evaluate differences in oil extraction, mass of fat recovery, and nutritional profiles of indigenous genotypes and introduced hybrids across different age categories and the three districts. The analysis revealed no statistically significant differences between indigenous genotypes and introduced hybrid varieties; however, indigenous genotypes recorded marginally higher mean values for both oil extraction rate (23.3%) and fat recovery (22.6%) compared to the introduced hybrids (22.8% and 17.9%, respectively). Indigenous oil palm genotypes demonstrated significantly higher concentrations of unsaturated fatty acids, particularly oleic acid, as well as elevated levels of beta-carotene, indicating superior nutritional quality compared to the introduced hybrid varieties. Conversely, the hybrids were characterized by higher carotenoid content. These findings underscore the potential of indigenous genotypes as valuable genetic resources for developing breeding lines aimed at improving both oil quality and yield under local agro-ecological conditions.
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    Relative abundance, geographical distribution, and utilization of the edible wild black plum (Vitex doniana) in Uganda
    (Springer Nature, 2025-08-04) Caku, Jimmy; Kesawat, Mahipal S.; Ddamulira, Gabriel; Masika, Fred Bwayo
    Wild edible plants play a crucial role in food security, biodiversity conservation, and sustaining rural livelihoods. Vitex doniana, though widely distributed, remains an underutilized species with significant ecological, economic, and medicinal value. Despite its adaptability across diverse ecosystems, its population in Uganda faces increasing threats from human activities. In addition, the lack of comprehensive data on its abundance and distribution hampers conservation efforts, posing a risk to the plant’s genetic diversity. Ecological and ethnobotanical surveys were conducted in Uganda, Koboko district, to assess the abundance, utilization, and distribution of V. doniana. A total of six line transects and 18 quadrats (three alternating quadrats (50 m × 100 m) with 25 m spacing between quadrats per line transect) were used for data collection. A pre-tested questionnaire was used to collect data on the utilisation of V. doniana from 144 respondents. Data were analysed using descriptive statistics and Chi-square tests in SPSS. Results indicated a higher relative abundance of young regenerating trees (74.0%) than mature trees (26.0%). The distribution of V. doniana across different land-use types showed a statistically significant variation (χ² = 7.17, df = 2, p = 0.028). The local community utilizes the tree for fruit harvesting, firewood, charcoal production, and construction purposes. To ensure the sustainable use of V. doniana, community by-laws, awareness, controlled harvesting, and agroforestry practices should be embraced.