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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    Comparative analysis of oil palm extraction rates and nutritional profiles of indigenous and introduced hybrid genotypes cultivated in selected districts of Uganda
    (Taylor & Francis, 2026-04-04) Caku, Jimmy; Ddamulira, Gabriel; Nuwamanya, Ephraim; Ddumba, Gerald; Mahipal, Kesawat Singh; Asiimwe, Alex; Amugoli, Otuba Moses; Alicai, Titus; Masika, Fred Bwayo
    Oil palm (Elaeis guineensis Jacq. L.) is the leading global source of plant-based oil. However, Uganda relies on imported hybrid varieties because it lacks a domestic breeding program. To inform potential breeding efforts, this study evaluated oil extraction rates and nutritional profiles of indigenous and introduced hybrid oil palm genotypes cultivated in Bundibugyo, Kanungu, and Kalangala districts. Seventy-five ripe fruit bunches were collected, and palm oil was extracted using a screw press. Measurements of oil extraction rate and stearin mass recovery were performed. Nutritional analysis of olein samples included carbohydrate quantification via the Anthrone method; fatty acid quantification (linolenic, linoleic, oleic, palmitic, and stearic acids) using High-Performance Liquid Chromatography (HPLC) with UV detection; and beta-carotene concentration determined using spectrophotometry. Statistical differences between groups were assessed using the non-parametric Kruskal-Wallis H test, as data for most variables did not meet the assumptions for parametric tests. Indigenous genotypes showed slightly higher mean oil extraction rates (23.3%) and stearin recovery (22.6%) than hybrids (22.8 and 17.9%, respectively). These results highlight the potential of indigenous genotypes as promising candidates for breeding programs aimed at enhancing oil yield and nutritional quality under Uganda’s agro-ecological conditions. The study provides foundational data to support the development of a sustainable, locally adapted oil palm breeding initiative.
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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.
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    Unlocking Ugandan pumpkin landrace diversity: integrated morphological and nutritional profiling for food security and breeding innovation
    (Taylor & Francis, 2026-04-13) Masika, Fred Bwayo; Anywar, Godwin; Kesawate, Mahipal Singh; Ddamulira, Gabriel; Kawuma, Caro; Andama, Morgan; Ajoma, Charity; Ramathan, Iddi; Amugoli, Otuba Moses; Caku, Jimmy; Alicai, Titus; Nuwamanya, Ephraim; Tugume, Arthur K.
    Pumpkins (Cucurbita spp.) are vital for food and nutritional security in Uganda, yet their full potential remains underexploited due to the limited characterization of traits. To address this, 91 landraces, 21 Cucurbita pepo and 70 Cucurbita moschata were collected from 19 districts across major agroecological zones, evaluated for morpholological and nutritional diversity. Results revealed wide phenotypic variation with fruit weights ranging from 0.5 to 10.0 kg and shapes varying from discoid (L/D 0.44) to highly elongated (L/D 4.00). Fruit size and shape were independent axes of variation. Regionally, Buganda and Bunyoro landraces produced larger fruits, averaging 3.84 kg and 4.07 kg, while West Nile landraces formed a distinct nutrient-rich cluster, with high dry matter (22.8%), lipids (3.75% fresh weight (FW), fiber (3.34% FW), and carbohydrates (4.07% FW). District-specific differences were also observed, with Mpigi landraces rich in phenolics content (0.062 ± 0.0023 g GAE/100 g), and Mukono landraces rich in proteins (0.000887 g/100 g). Importantly, external morphology poorly predicted internal nutritional quality, highlighting the need for direct biochemical profiling in breeding programs. This study provides Uganda’s first nationally structured dataset on pumpkin diversity, offering a scientific foundation for targeted germplasm conservation, nutrient-enriched cultivar development and policy interventions to strengthen food systems across diverse agroecological zones in Uganda.