Browsing by Author "Wacoo, Alex Paul"

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    Feasibility of a novel on-site detection method for aflatoxin in maize flour from markets and selected households in Kampala, Uganda
    (MDPI AG, 2018-08-11) Wacoo, Alex Paul; Wendiro, Deborah; Nanyonga, Sarah; Hawumba, Joseph F.; Sybesma, Wilbert; Kort, Remco
    In sub-Saharan Africa, there is a high demand for affordable and accessible methods for on-site detection of aflatoxins for appropriate food safety management. In this study, we validated an electrochemical immunosensor device by the on-site detection of 60 maize flour samples from six markets and 72 samples from households in Kampala. The immunosensor was successfully validated with a linear range from 0.7 ± 0.1 to 11 ± 0.3 µg/kg and limit of detection (LOD) of 0.7 µg/kg. The maize flour samples from the markets had a mean total aflatoxin concentration of 7.6 ± 2.3 µg/kg with approximately 20% of the samples higher than 10 µg/kg, which is the maximum acceptable level in East Africa. Further down the distribution chain, at the household level, approximately 45% of the total number contained total aflatoxin levels higher than the acceptable limit. The on-site detection method correlated well with the established laboratory-based HPLC and ELISA-detection methods for aflatoxin B1 with the correlation coefficients of 0.94 and 0.98, respectively. This study shows the feasibility of a novel on-site detection method and articulates the severity of aflatoxin contamination in Uganda.
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    Improving health and wealth by introduction of an affordable bacterial starter culture for probiotic yoghurt production in Uganda
    (Challenges, 2019) Westerik, Nieke; Wacoo, Alex Paul; Anyimo, Esther; Matovu, William; Reid, Gregory; Kort, Remco; Sybesma, Wilbert
    In rural Africa, income generating activities of many households heavily depend on agricultural activities. In this paper, we present the results of a multi-year intervention whereby dairy farmers and small-scale entrepreneurs were taught to convert their milk into a probiotic yoghurt using an innovative bacterial starter culture and basic equipment. This intervention creates additional sources of income and employment for people involved in the delivery of milk as well as production, distribution, and sales of yoghurt. Besides the economic benefits, the consumption of the probiotic yoghurt can contribute to reduction of the incidence and severity of diarrhea, respiratory tract infections, atopic diseases, alleviate the symptoms of stomach ulcers, and decrease the uptake of aflatoxins in the body. With minimal external financial support, 116 communities or small entrepreneurs have been able to start, expand, and maintain a business by production and sales of probiotic yoghurt. Applied business models and success rate in terms of revenues and profitability varied per region and depended on location, culture, ownership structure, wealth status, and gender.
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    Potential application of lactic acid starters in the reduction of aflatoxin contamination in fermented sorghum-millet beverages
    (International Journal of Food Contamination, 2019) Byakika, Stellah; Mukisa, Ivan Muzira; Wacoo, Alex Paul; Kort, Remco; Byaruhanga, Yusuf Byenkya; Muyanja, Charles
    Background: Aflatoxin contamination in traditionally fermented cereal-based beverages is a serious food safety challenge considering that commercialization of these products is rising. The challenge is aggravated by the fact that aflatoxin elimination from the food chain is almost impossible. This paper focuses on Obushera, a popular traditional spontaneously fermented sorghum – millet beverage from Uganda. Method: Mold and total aflatoxin levels in cereal flours and Obushera from different markets in Kampala were determined. Ability of lactic acid bacteria (LAB) starters from Obushera; Lb. plantarum MNC 21, W. confusa MNC 20 and L. lactis MNC 24 to bind aflatoxin B1 (AFB1) was evaluated against Lb. rhamnosus yoba 2012 as the reference strain. Results: Mold counts in sorghum, millet and Obushera ranged between 0.0–2.4 log cfu/g, 2.0–6.5 log cfu/g and 2.0–5.5 log cfu/g, respectively. None of the flours complied with food safety standards for molds (maximum = 4 log cfu/g) while 88.0% of Obushera did (standard = maximum 1.3 log cfu/g). Total aflatoxin levels in sorghum, millet and Obushera were 22.3 ± 21.2 ppb, 9.9 ± 10.0 ppb and 10.4 ± 6.1 ppb, respectively. LAB bound 19.3–69.4% of AFB1 in a 1000 ppb solution with binding efficiency in the order of Lb. rhamnosus yoba 2012 = Lb. plantarum MNC 21 > W. confusa MNC 20 = L. lactis MNC 24. The LAB-AFB1complex remained stable under a series of washes with physiological saline. Conclusion: This study indicates that LAB with aflatoxin binding properties can be exploited for controlled cereal fermentations to improve food safety.
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    Probiotic enrichment and reduction of aflatoxins in a traditional African maize-based fermented food
    (Nutrients, 2019) Wacoo, Alex Paul; Mukisa, Ivan Muzira; Meeme, Rehema; Byakika, Stellah; Wendiro, Deborah; Sybesma, Wilbert; Kort, Remco
    Fermentation of food products can be used for the delivery of probiotic bacteria and means of food detoxification, provided that probiotics are able to grow, and toxins are reduced in raw materials with minimal effects on consumer acceptability. This study evaluated probiotic enrichment and detoxification of kwete, a commonly consumed traditional fermented cereal beverage in Uganda, by the use of starter culture with the probiotic Lactobacillus rhamnosus yoba 2012 and Streptococcus thermophilus C106. Probiotic kwete was produced by fermenting a suspension of ground maize grain at 30 ◦C for a period of 24 h, leading to a decrease of the pH value to ≤ 4.0 and increase in titratable acidity of at least 0.2% (w/v). Probiotic kwete was acceptable to the consumers with a score of ≥6 on a 9-point hedonic scale. The products were stable over a month’s study period with a mean pH of 3.9, titratable acidity of 0.6% (w/v), and Lactobacillus rhamnosus counts >108 cfu g-1. HPLC analysis of aflatoxins of the water-soluble fraction of kwete indicated that fermentation led to an over 1000-fold reduction of aflatoxins B1, B2, G1, and G2 spiked in the raw ingredients. In vitro fluorescence spectroscopy confirmed binding of aflatoxin B1 to Lactobacillus rhamnosus with an efficiency of 83.5%. This study shows that fermentation is a means to enrich with probiotics and reduce widely occurring aflatoxin contamination of maize products that are consumed as staple foods in sub-Saharan Africa
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    Utilization of solid waste as a substrate for production of oil from oleaginous microorganisms
    (Hindawi, 2018-05-16) Laker, Fortunate; Agaba, Arnold; Akatukunda, Andrew; Gazet, Robert; Barasa, Joshua; Nanyonga, Sarah; Wendiro, Deborah; Wacoo, Alex Paul
    The overwhelming demand of oil and fats to meet the ever increasing needs for biofuel, cosmetics production, and other industrial purposes has enhanced a number of innovations in this industry. One such innovation is the use of microorganisms as alternative sources of oil and fats. Organic solid waste that is causing a big challenge of disposal worldwide is biodegradable and can be utilized as substrate for alternative oil production.The study evaluated the potential of isolated yeast-like colonies to grow and accumulate oil by using organic solid waste as substrate. Of the 25 yeast-like colonies isolated fromthe soil samples collected fromthree different suburbs in Kampala district, Uganda, 20 were screened positive for accumulation of lipid but only 2 were oleaginous. The NHC isolate with the best oil accumulation potential of 48.8% was used in the central composite design (CCD) experiments. The CCD experimental results revealed a maximum oil yield of 61.5% from 1.25 g/L cell biomass at 10 g/L of solid waste and temperature of 25∘C. The study revealed that organic solid waste could be used as a substrate for microbial oil production.