Browsing by Author "Mugabi, Robert"

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    Antimicrobial Activity of Lactic Acid Bacteria Starters against Acid Tolerant, Antibiotic Resistant, and Potentially Virulent E. coli Isolated from a Fermented Sorghum-Millet Beverage
    (International Journal of Microbiology, 2019) Byakika, Stellah; Muzira Mukisa, Ivan; Mugabi, Robert; Muyanja, Charles
    Bacterial contamination of fermented foods is a serious global food safety challenge that requires effective control strategies. -is study characterized presumptive E. coli isolated from Obushera, a traditional fermented cereal beverage from Uganda. -ereafter, the antimicrobial effect of lactic acid bacteria (LAB) previously isolated from Obushera, against the E. coli, was examined. -e presumptive E. coli was incubated in brain heart infusion broth (pH � 3.6) at 25°C for 48 h. -e most acid-stable strains were clustered using (GTG)5 rep-PCR fingerprinting and identified using 16S rRNA sequencing. E. coli was screened for Shiga toxins (Stx 1 and Stx 2) and Intimin (eae) virulence genes as well as antibiotic resistance. -e spot-on-the-lawn method was used to evaluate antimicrobial activity. Eighteen isolates were acid stable and are identified as E. coli, Shigella, and Lysinibacillus. -e Stx 2 gene and antibiotic resistance were detected in some E. coli isolates. -e LAB were antagonistic against the E. coli. Lactic acid bacteria from traditional fermented foods can be applied in food processing to inhibit pathogens. Obushera lactic acid bacteria could be used to improve the safety of fermented foods.
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    Effects of Feed Moisture Content, Soybean Ratio and Barrel Temperature on Physical and Functional Properties of Extruded Maize-Soybean Flour Blends
    (Tanzania Journal of Science, 2022) Mugabi, Robert; Byakika, Stellah; Muzira Mukisa, Ivan
    The effects moisture content, temperature and soybean ratio on expanded product characteristics of extruded maize-soybean blends were studied. Response surface methodology was used to study the effects of extrusion conditions on extrudate properties taking barrel temperature (BT), feed moisture content (FM) and soybean flour ratio (SR) as factors. Expansion ratio (ER), water absorption index (WAI), water solubility index (WSI), hardness and colour (b* - (+) yellowness) of the extrudates were determined. BT and FM had significant effects on ER (p < 0.05). At low FM levels, ER increased with BT. It was observed that both FM and BT significantly affected WAI and WSI. WAI increased as FM increased. Increasing FM to 20% resulted in a decrease in WSI, beyond which an increase was observed. Hardness increased significantly as feed moisture content increased. High SR content significantly increased the extrudate hardness. FM had no significant effect on colour. Colour increased as the SR and BT increased. Significant regression models explained the effects of SR, FM, and BT on all response variables. All of the response variables' R2, were higher than 0.89.