Browsing by Author "Nuwamanya, Ephraim"

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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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    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.