Browsing by Author "Byenkya Byaruhanga, Yusuf"

Now showing 1 - 8 of 8
  • Thumbnail Image
    Item
    Characterizing Selected Sorghum Grain Varieties and Evaluating the Suitability of Their Malt Extracts for Cultivating Microbial Biomass
    (International Journal of Food Science, 2021) Byakika, Stellah; Muzira Mukisa, Ivan; Byenkya Byaruhanga, Yusuf
    Microbial biomass is cultivated for different technological applications including food processing, medicine, waste management, and research. The conventional growth media used are generally expensive thus necessitating the development of more affordable alternatives. In this study, four sorghum grain varieties, SESO 1, SESO 3, Epuripur, and Eyera, and their malt extracts were characterized which is aimed at determining their suitability for growing microbial biomass. The varieties had kernel length, kernel width, kernel thickness, and thousand kernel weigh equivalent to 3.8-4.3 mm, 3.2-4.5 mm, 2.4-2.8 mm, and 12.4-20.2 g, respectively. SESO 1 and Epuripur had corneous endosperm textures whereas those of SESO 3 and Eyera were intermediate and floury, respectively. Varieties had germinative energies > 90% and total defects < 8%. SESO 3 had the highest (p < 0:05) crude protein (10:8 ± 0:3%) and dietary fiber (22:5 ± 0:4%) whereas Epuripur had the highest (p < 0:05) starch (81:6 ± 0:0%) and crude fat (2:9 ± 0:1%). There was no significant difference (p > 0:05) in the ash contents (2:1 ± 0:0%). The total sugars, free amino nitrogen, condensed tannins, and pH of the malt extracts were 106-116 g/L, 70-78 mg/L, 0.1-0.6 mg/mL, and 5.5-5.7, respectively. The composition of the sorghum malt extracts suggests their potential for use in cultivating microbial biomass.
  • Thumbnail Image
    Item
    Food Safety Knowledge, Attitudes and Practices of Food Handlers along the Rice Value Chain of Uganda
    (Journal of Food Industry, 2022) Namubiru, Leatitiah; Male, Denis; Muzira Mukisa, Ivan; Byenkya Byaruhanga, Yusuf
    Food handlers play a critical role in controlling food contamination from “farm to fork”. Therefore, inadequate knowledge, poor attitudes and improper practices by food handlers pose a serious challenge to food safety. The aim of this study was to assess the knowledge, attitudes, and practices (KAP) of food handlers along the rice value chain of Uganda with the view of understanding factors that influence contamination of rice with aflatoxins, heavy metals and pesticides. A cross-sectional study, using a structured questionnaire through face-to-face interviews with 252 respondents was conducted in Butaleja, Gulu, Hoima, Kampala, Mutukula, Mbale and Mbarara districts. Categorical data was expressed as frequencies and percentages. The unique predictors of the KAP of rice handlers were defined using multivariate linear regression analysis. About 221 (87.7%) food handlers knew about the occurrence and causes of aflatoxins contamination in rice. Changes in colour (81.7%) and a musty smell (82.9%) were perceived to indicate the presence of aflatoxins. The main preand post-harvest aflatoxin preventative practices identified were growing resistant rice varieties (82.9%) and proper drying (79.8%). Food handlers were generally not knowledgeable (73.4%) about heavy metal contamination in rice. All food handlers used pesticides; however, 68.3% had never received formal training in pesticide use. Majority (86.1%) of food handlers were aware of the harmful effects of pesticides but on the contrary, this did not significantly change their practices towards safe pesticide use. At multivariate level, education was the unique predictor for aflatoxins and heavy metal contamination. Pesticide contamination was mainly influenced by district of residence. Therefore, appropriate educational programs organized to train food handlers can promote food safety in the rice value chain of Uganda. Interventions by regulatory agencies to strengthen enforcement of laws related to contaminants through regular surveillance at the farm and retail outlets are necessary to ensure compliance by food handlers.
  • Thumbnail Image
    Item
    Influence of food safety knowledge, attitudes and practices of processors on microbiological quality of commercially produced traditional fermented cereal beverages, a case of Obushera in Kampala
    (Food Control, 2019) Byakika, Stellah; Muzira Mukisa, Ivan; Byenkya Byaruhanga, Yusuf; Male, Denis; Muyanja, Charles
    Traditionally, fermented foods were only consumed in regions of their origins but owing to increasing demand, some are finding their way into foreign markets. The challenge though, is the generally uncontrolled nature of the fermentations which raises safety concerns. This paper highlights the food safety challenges associated with traditional fermented foods with a special focus on commercially produced and packaged Obushera, a Ugandan traditional fermented cereal beverage. Microbial counts, titratable acidity (TA) and pH of Obushera samples (n=59) were determined. Food safety knowledge, attitudes and practices (KAP) of processors (n=47) were also evaluated. About 50% of samples did not conform to safety requirements. Obushera had 0.0–7.3 log cfu/mL total and thermo-tolerant coliforms, 0.0–6.2 log cfu/mL E. coli and 0.0–8.1 log cfu/mL Staphylococcus spp. Flour samples had 3.7–7.3 log cfu/g total coliforms, 3.2–7.1 log cfu/g thermo-tolerant coliforms, 1.0–4.9 log cfu/g E. coli and 2.4–7.3 log cfu/g Staphylococcus spp. Salmonella spp was not detected. Obushera (56 out of 59 samples) with pH≤4.0 and TA=0.1–3.1% had coliforms and Staphylococcus spp above the recommended minimum values. Scores showed that processors had fairly good knowledge (63.0 ± 2.3%) and attitudes (52.2 ± 3.0%) but poor practices (38.7 ± 2.4%). There was no correlation between the KAP and product quality. Therefore, processors should adopt better processing technologies that enhance food safety. There is also need for enforcement and regulation of food safety by concerned authorities. Trainings for processors should aim at positively changing their attitudes and causing them to adopt appropriate practices.
  • Thumbnail Image
    Item
    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; Muzira Mukisa, Ivan; Paul Wacoo, Alex; Kort, Remco; Byenkya Byaruhanga, Yusuf; Muyanja, Charles
    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.
  • Thumbnail Image
    Item
    Probiotic Potential of Lactic Acid Starter Cultures Isolated from a Traditional Fermented Sorghum-Millet Beverage
    (International Journal of Microbiology, 2020) Byakika, Stellah; Mukisa, Ivan Muzira; Byenkya Byaruhanga, Yusuf; Muyanja, Charles
    )e purpose of this study was to establish the probiotic potential of lactic acid bacteria (LAB) starter cultures, Lb. plantarum MNC 21, L. lactisMNC 24, and W. confusaMNC 20, isolated from a traditionally fermented sorghum-millet beverage from Uganda. )e cultures were examined for tolerance to acid and bile salts, bile salt hydrolase (BSH) activity, antibiotic susceptibility, biogenic amine production, mucin degradation, hydrophobicity, auto-aggregation, adherence to the ileum, coaggregation, and antimicrobial properties against selected pathogenic species. Lb. rhamnosus yoba 2012, a known probiotic, was the reference. )e isolates were tolerant to acid (pH � 3) and bile (1%). W. confusa MNC 20 and Lb. plantarum MNC 21 exhibited medium BSH activity (11–15mm diameter of hydrolysis zone) while L. lactis and Lb. rhamnosus yoba 2012 exhibited low BSH activity (<10mm diameter of hydrolysis zone). All isolates lacked mucolytic activity. Lb. plantarum MNC 21 and W. confusa MNC 20 produced agmatine. )e candidate and reference microorganisms were resistant to 10 of 21 and 5 of 21 antibiotics, respectively. )e isolates exhibited hydrophobic, auto-aggregation and coaggregation properties. )ese three properties were exhibited more (p < 0.05) by the reference than the potential probiotics. )e ability of the potential probiotics to attach onto the goat ileum (7.3–8.0 log cfu/ cm2) was comparable to that of Lb. rhamnosus yoba 2012 (7.6 log cfu/cm2).)efour LAB inhibited E. coli, S. aureus, and S. enterica to the same extent (p < 0.05). )e findings indicated potential probiotic activity of the starter cultures. However, further in vivo examination of these isolates is required to confirm their probiotic capabilities.
  • Thumbnail Image
    Item
    A Review of Criteria and Methods for Evaluating the Probiotic Potential of Microorganisms
    (Food Reviews International, 2019) Byakika, Stellah; Muzira Mukisa, Ivan; Byenkya Byaruhanga, Yusuf; Muyanja, Charles
    Probiotics are live organisms that, when consumed in sufficient quantities, confer health benefits to the host. There is global interest in probiotics research; many are isolated from diverse niches and identified in numerous ways. The challenge is selecting the precise range of tests and methods to use. Some tests are argued to be outdated, biased and/or irrelevant. Screening guidelines exist, but at times are not strictly followed. In many countries, firm regulations regarding probiotics declaration and use are nonexistent. Consequently, some organisms are presented as probiotics without strong scientific evidence. This review discusses common screening approaches, their relevance, strengths and weaknesses. Abbreviations: ADP: Adenosine Diphosphate; ATCC: American Type Culture Collection; ATP: Adenosine Triphosphate; BSH: Bile Salt Hydrolase; Caco-2: Cancer coli-2; cFDA-SE: Carboxyfluorescein diacetate succinimidyl ester; CLSI: Clinical and Laboratory Standards Institute; DNA: Deoxyribonucleic acid; EPN: Epinephrine; FAO: Food and Agriculture Organization; FbPA: Fibronectin binding protein A; FDA: Food and Drug Authority; GIT: Gastrointestinal tract; GRAS: Generally Recognized as Safe; HEPES : 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid; HT-29: Human colon adenocarcinoma cells; HT-29 MTX: Methotrexate treated human colon adenocarcinoma cells; ICMR-DBT: Indian Council of Medical Research and Department of Biotechnology; IBS: Irritable Bowel Syndrome; ICR: Inherited Cataract Rat; LAB: Lactic Acid Bacteria; MFI: Mean Fluorescence Intensity; MIC: Minimum Inhibitory Concentration; mRNA: Messenger Ribonucleic Acid; MRS: de Man Rogosa Sharpe; NCCB: Netherlands Culture Collection of Bacteria; OD: Optical Density; PBS: Phosphate Buffered Saline; PGE: Prostaglandin; RBC: Red Blood Cells; SHIME: Simulator of the Human Intestinal Microbial Ecosystem; SDSPAGE: Sodium Dodecyl Sulfate Polyacrylamide Gel Electrophoresis; TLC: Thin-Layer Chromatography; TRAP-6: Thrombin Receptor Activator Peptide-6; WHO: World Health Organization
  • Thumbnail Image
    Item
    Sorghum Malt Extract as a Growth Medium for Lactic Acid Bacteria Cultures: A Case of Lactobacillus plantarum MNC 21
    (International Journal of Microbiology, 2020) Byakika, Stellah; Muzira Mukisa, Ivan; Byenkya Byaruhanga, Yusuf
    Cultivation of lactic acid bacteria cultures is vital for research and commercial production of fermented foods. However, the conventional growth media used are generally costly. Malt extracts from four sorghum varieties (SESO 1, SESO 3, Epuripur, and Eyera) were evaluated as alternative low-cost growth media for Lactobacillus plantarum MNC 21. Saccharified sorghum malt extracts were inoculated with 4 log cfu/mL MNC 21 and incubated at 30°C for 24 h. MRS broth was the reference medium. Microbial counts, pH, titratable acidity (TA), free amino nitrogen (FAN), and total sugars were measured. Maximum microbial counts in the extracts and MRS broth were 9 and 10 log cfu/mL, respectively. Maximum growth rate in the extracts was 0.7–0.9 log cfu/mL/h and 0.8 log cfu/mL/h in MRS broth. (e final pH of the extracts was 3.5–3.6, with an overall increase in TA of 1.2% in Epuripur and 0.2% in other varieties. Final pH and TA of MRS broth were 4.1 and 1.3%, respectively. Total sugars dropped by 95.2% and FAN by 2.1% in MRS broth. In contrast, total sugars and FAN dropped by 5.6–9.1% and 24.9–32.7% respectively, in the extracts. Sorghum malt extracts can be adopted as alternative low-cost growth media for lactic acid bacteria cultures.
  • Thumbnail Image
    Item
    Toxicological Risk Associated with Consumption of Rice Sold in Uganda
    (International Journal of Scientific Advances, 2021) Namubiru, Leatitiah; Male, Denis; Mukisa Muzira, Ivan; Byenkya Byaruhanga, Yusuf
    Previous studies have reported the presence of aflatoxins (AFB1, AFB2, AFG1 and AFG2), heavy metals (As, Cd and Pb) and organochlorine pesticide residues (OCPs) in rice sold in Uganda. However, the potential health effects associated with consumption of rice have not been evaluated. The aim of this study was to evaluate the health risk of consuming rice sold in Uganda. A total of 45 packed and 30 open traded rice samples were randomly collected from retail outlets in the main rice trading areas of Uganda. Rice was analysed for AFB1, AFB2, AFG1 and AFG2, As, Cd, Pb and OCPs using AOAC standard methods. Dietary exposure of the consumers to contaminants was assessed using the estimated daily intake (EDI). The Hazard index (HI) and the incremental lifetime cancer risk (ILCR) were determined to define the non-carcinogenic and carcinogenic risk from contaminants, respectively. The potency of liver cancer cases in Uganda was 1.02E-5 and 1.05E-5 adults/year/100,000, and 6.50E-4 and 6.72E-5 infants /year/100,000 for open traded and packed rice, respectively. The values obtained for the ILCR for Arsenic detected in rice were 1.14E-2 and 7.28E-2 for adults and infants, respectively. The ILCR of all detected OCPs in adults and infants were higher than 1.0E-4, in both open traded and packed rice. This study established a potential carcinogenic risk from consumption of rice sold in Uganda in both infants and adults at the current level of contamination and consumption rate. Establishment of a monitoring system along the entire rice value chain; enforced by a national regulatory body can provide timely feedback on the levels of contamination and the progress in reducing the contamination burden.