School of Biosecurity, Biotechnolgy and Laboratory Sciences (SBLS) Collection

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https://dissertations.mak.ac.ug/handle/20.500.12281/6445

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Browsing School of Biosecurity, Biotechnolgy and Laboratory Sciences (SBLS) Collection by Subject "Aflatoxins"
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    Aflatoxins and ochratoxins detection in cinnamon spices sold in selected supermarkets in Kira Municipality, Uganda
    (Makerere University, 2022-12) Nakalembe, Latifah
    Spices are one of the flavoring components of food in the cooking recipes of different nations that are used daily. Studies have shown that, these ingredients may be contaminated by toxicogenic fungi and subsequent production of mycotoxins that cannot be neutralized through cooking. In Uganda, cinnamon is one of the commonest spices used and often sold in supermarkets, but there is limited literature about its safety in terms of mycotoxin contamination which could lead to serious health hazards. In the present study, the possible contamination of cinnamon spices by aflatoxins (AF) and ochratoxin (OT) was investigated from samples collected around different supermarkets in Kira municipality, Uganda. A total of 27 powdered cinnamon spice samples were purchased from supermarkets around Kira municipality. Extraction of AF and OT was done using solvent extraction method at Analytical Biosciences Laboratory, Makerere University AR grade reagents were used and additionally, screening of AF and OT was done using thin layer chromatography and high performance thin layer chromatography respectively. Data was analyzed using STATA software package version 15, and the respective frequencies of each mycotoxin calculated and results recorded. The results showed that all the screened cinnamon spice samples were contaminated with AF and 26 samples (96.3%) with OT. Regarding the high mycotoxins contamination in cinnamon spices as shown in the current study, this indicates that there is a high yet unregulated consumption of mycotoxins in the community which has been proven to be detrimental to health. A quantitative study should be carried out and regular effective surveillance by UNBS and quality control procedures are highly recommended.
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    Detection of aflatoxins in maize grains and maize flour from Central and Eastern Uganda
    (Makerere University, 2022-12) Naluwooza, Sophia Sseruwo
    Aflatoxins are secondary fungal metabolites known to be carcinogenic, teratogenic, mutagenic, immunosuppressive, and mutagenic. Several studies have reported presence of aflatoxins in different food matrices, in various countries particularly in the tropics. With the available information on aflatoxins, there is need for continuous update on aflatoxin status in foodstuffs in Uganda. Maize being the most consumed food stuff in Uganda, status of aflatoxins in maize and maize flour was examined. Aflatoxins we're extracted using solvent-solvent extraction and screened using Thin Layer Chromatography. From the study, 65.45% of the samples was positive for aflatoxins with the samples from central region being more contaminated than those from eastern region. This therefore signifies that the health of the maize consumers is at risk of aflatoxin poisoning. Basing on these findings, I recommend that a quantitative study if aflatoxins in maize should be conducted. Further studies on the prevalence of aflatoxins in the whole country in different food stuffs should as well be done.
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    Handling practices and aflatoxin contamination of the dry wild edible mushrooms sold in Rushere town council Kiruhura District Western Uganda.
    (Makerere University, 2022-01) Tandeka, Emmanuel
    Aflatoxins are secondary metabolites produced by Aspergillus species of fungus which include Aspergillus flavus and Aspergillus parasiticus. Aflatoxin presence in various foods is considered as a health threat across the globe due to their carcinogenic, teratogenic, and growth retardation ability and immunosuppressive effects. The aflatoxin presence in different foods is influenced by several factors including prolonged period of storage, temperature range of 25 to 35°C and moisture contents at adsorption equilibrium with relative humidity of 80% to 100%. More research has been done on aflatoxin contamination in different foods in developed countries. In Uganda minimal research has been done on aflatoxin contamination in the dry wild edible mushrooms. Therefore this study was conducted to assess the handling practices, detect the presence of aflatoxins in the dry wild edible mushrooms sold in Rushere Town Council Kiruhura district. 30 samples of three different wild edible mushroom species were collected from different traders. A questionnaire was used to collect data on the handling practices including nature of the packaging material, storage time and pest infestation among traders in Rushere town council. Thin layer chromatography method was used for detection of aflatoxin in the mushroom samples where 30 samples containing three mushroom species were analysed and 90% tested positive for aflatoxins whereas 10% tested negative for aflatoxins. 80% tested positive for aflatoxin B and only 20% tested negative for aflatoxin B. 73.3% tested positive for aflatoxin G whereas 26.7% tested negative for aflatoxin G. The study found out that 23.3% of the traders packed their mushrooms in intact polyethene bags, 76.7% used polyethene bags that had holes in them. 60% of the traders had their mushrooms free from insect infestation, 40% of the traders had their mushrooms infested with insects. 63.3% of the traders had stored their mushrooms for a period of more than one month while 36.7% had store their mushrooms for a period of ≤ 1 month. The association of aflatoxin contamination in the dry wild edible mushrooms and the related handling practices is a complex web and this study revealed that there was no significant association between the nature of the packaging material evaluating whether the material was intact or had holes and aflatoxin contamination at 95% confidence intervals with the p-value of 0.060 which is greater than 0.05. There was a significant association between the storage time and aflatoxin contamination with the p-value of 0.006 which is less than 0.05. There was also no significant association between pest infestation and aflatoxin status with the p-value of 0.076 which is greater than 0.05. Therefore the local authorities need to work together with the traders to ensure that handling practices are up to the required standard
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    Post harvest handling practices and aflatoxin contamination levels of cassava flour samples from Alur and Acholi cultural settings, Northern Uganda
    (Makerere University, 2025) Mungungeo, David
    Aflatoxins are toxic mycotoxins produced by fungi like Aspergillus flavus and A. parasiticus, prevalent in warm, humid regions, particularly Sub-Saharan Africa. In Uganda the primary aflatoxins of concern are AFB1, AFB2, AFG1, AFG2, AFM1, and AFM2 (Lukwago et al., 2019). Aflatoxin-producing fungi can contaminate crops in the field, harvest time and postharvest period. Cassava is a staple food in Northern Uganda, particularly among Alur and Acholi communities, but it faces high risks of aflatoxin contamination due to traditional postharvest handling practices. This study assessed post-harvest handling practices and aflatoxin contamination levels of cassava flour samples from Alur and Acholi cultural settings, Northern Uganda. The study identified and compared the traditional cassava processing methods in the two cultural settings, determined the level of aflatoxins contamination in cassava flour, and evaluated the influence of specific post-harvest handling practices on contamination levels. A cross-sectional study design was employed, involving the collection of 36 cassava flour samples from Nebbi Municipality (Alur) and Gulu City (Acholi). Samples were analyzed using Thin Layer Chromatography (TLC) at Analytical Biosciences Laboratory, Makerere University. Data was collected using structured questionnaires, field observation, and interviews, and analyzed using SPSS, Excel, and descriptive statistics. Results showed that all Cassava flour samples were positive for Aflatoxin B, but negative for Aflatoxin G, 66.67% of cassava flour samples exhibited very high levels of aflatoxin B contamination, mainly associated with heap-mold fermentation practiced in Alur culture. Storage duration was found to have a statistically significant association with aflatoxin contamination levels (χ² = 8.701, p = 0.013 where X2 , the chi-square value is deviation of observed data from expected data. And P-value is probability of obtaining X2 ). The study also established that heap fermentation, prolonged storage, and poor drying methods increased contamination risks. Conversely, the chips drying method used in Acholi culture, use of tarpaulin drying platforms, shorter drying durations, and plastic storage containers reduced aflatoxin risks. The study recommends adoption of safer drying and storage methods, limiting storage duration to under one month, promoting chips drying, and strengthening post-harvest training and policies to safeguard cassava consumers against aflatoxin-related health risks